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The purpose of this treatise is to discover a method by which we shall be able to syllogize about every proposed problem from probabilities, and when we ourselves sustain the argument we may assert nothing repugnant. First, then, we must declare what a syllogism is and what are its differences, in order that the dialectic syllogism may be apprehended, for we investigate this in the proposed treatise.

A syllogism then is a discourse in which, certain things being laid down, something different from the posita happens from necessity through the things laid down. Demonstration indeed is when a syllogism consists of things true and primary, or of such a kind as assume the principle of the knowledge concerning them through certain things primary and true; but the dialectic syllogism is that which is collected from probabilities. Things true and primary indeed are those which obtain belief, not through others, but through themselves, as there is no necessity to investigate the "why" in scientific principles, but each principle itself ought to be credible by itself. Probabilities however are those which appear to all, or to most men, or to the wise, and to these either to all or to the greater number, or to such as are especially renowned and illustrious. Moreover a contentious syllogism is one which is constructed from apparent, but not real probabilities, and which appears to consist of probabilities, or of apparent probabilities. For not every thing which appears probable is so, since none of those which are called probable has entirely the superficial image (of probability), as happens to be the case about the principles of contentious arguments, since immediately, and for the most part, the nature of the false in them is evident even to those who have small perception. Let then the first of the syllogisms called contentious, be also called a syllogism, but let the other be a contentious syllogism, yet not a syllogism (simply), since it appears indeed to draw an inference, but does not collect one.

Besides all the above-named syllogisms, there are paralogisms, which consist of things peculiar to certain sciences, as happens to be the case in geometry, and those (sciences) allied to it. For this mode seems to differ from the syllogisms enumerated, since he who describes falsely, neither syllogizes from the true and primary, nor from the probable, for he does not fall into definition, since he neither assumes things which appear to all men, nor those which appear to the greater number, nor to the wise, and to these neither to all, nor to the greater part, nor to the most famous; but he makes a syllogism from assumptions, appropriate indeed to science, yet not from the true, as either by describing semicircles not as they ought to be, or by drawing certain lines not as they ought to be drawn, he produces a paralogism.

Let then the species of syllogisms, to comprehend them summarily, be those which I have stated, and in a word, to sum up all that have been spoken of, and those which shall be mentioned hereafter, let our definition be so far given, because we do not propose to deliver an accurate description of any of these, but wish merely to run through them briefly, thinking it quite sufficient according to the proposed method, in some way or other to be able to know each of them.

It will be consequent upon what we have stated to describe to what an extent and for what subjects this treatise is useful. It is so for three: exercise, conversation, philosophical science. That it is useful for exercise, appears evident from these, that possessing method, we shall be able more easily to argue upon every proposed subject. But for conversation (it is useful), because having enumerated the opinions of the many, we shall converse with them, not from foreign, but from appropriate dogmas, confuting whatever they appear to us to have erroneously stated. Again, (it is useful) for philosophical science, because being able to dispute on both sides, we shall more easily perceive in each the true and the false; also, (it is applicable) to the first principles of each science, since we cannot say any thing about these from the appropriate principles of a proposed science, as they are the first principles of all, but we must necessarily discuss these through probabilities in the singulars. This however is peculiar, or especially appropriate to dialectic, for being investigative, it possesses the way to the principles of all methods.

We shall possess this method perfectly when we are similarly disposed, as in rhetoric, medicine, and such like powers; and this is to effect what we choose from possibilities, since neither will the rhetorician persuade from every mode, nor the physician heal, but if a man omits no possibility we say that he sufficiently possesses science.

First then let us examine of what this method consists. If therefore we assume for how many, what kind of, and from what things, arguments are constructed, and how we may be well provided with these, we shall sufficiently gain our point. Now those things are equal and the same in number from which arguments are constructed, and about which syllogisms are conversant; for arguments are constructed of propositions, but the things with which syllogisms are conversant are problems. Now every proposition and every problem shows either genus, property, or accident; for difference, being generic, we must place together with genus. Since however of property, one kind signifies the very nature of a thing, but the other does not signify it, let property be divided into the two above-named parts, and let what signifies the very nature of a thing be called definition, but let the other, according to the common appellation attributed about these, be called property. Now it is clear from what we have said, that according to the present division it happens that all are four, either property, or definition, or genus, or accident. Let however no one suppose that we say that each of these asserted by itself is a proposition or a problem, but that problems and propositions are produced from these. Still a problem and a proposition differ in mode, since when it is thus said, is a pedestrian biped animal the definition of man? and is animal the genus of man? there is a proposition, but if (it should be said), whether is a pedestrian biped animal the definition of man or not? there is a problem. So also in other things. Wherefore with propriety problems and propositions are equal in number, for from every proposition you will make a problem by changing the mode.

We must describe what definition, property, genus, and accident are. Now definition is a sentence signifying what a thing is: and either a sentence is employed instead of a noun, or a sentence instead of a sentence, since it is possible to define some things which are signified by a sentence. As many however as in some way or other make the explanation by a noun, evidently do not explain the definition of the thing, since every definition is a certain sentence. Still we must refer a thing of this kind to definition, as that the becoming is beautiful; in like manner also whether sense and science are the same or different, since about these definitions, whether they are the same or different, there is a very great discussion. In short, however, all things may be called definitive which are under the same method with definitions, but that all which have been spoken of are of this kind is evident from these (considerations). For when we are able to argue that a thing is the same and that it is different, we shall by the same manner be well supplied with arguments about definitions, since when we have shown that it is not the same we shall have upset the definition. Still what is now said is not converted, since it is not enough to construct a definition to show that it is the same, but for the subversion of definition it is sufficient to show that it is not the same thing.

Property, indeed, is that which does not show what a thing is, but is present to it alone, and reciprocates with the thing. As it is the property of a man to be capable of grammar, for if he is a man he is capable of grammar, and if he is capable of grammar he is a man; since no one calls property that which may possibly be present with something else, as sleep to a man, not even if it should happen at a certain time to be present with him alone. If then any thing of this kind should be called property, it will not be called property simply, but at a certain time or with reference to something, since to be on the right hand is sometimes a property, but biped happens to be called property with reference to something, as to man with reference to horse and dog; but that nothing which may possibly be present with something else is reciprocally predicated is clear, since it is not necessary if any thing sleeps that it should be a man.

Genus, however, is that which is predicated of many things differing in species, in (answer to) what a thing is; but let those things be said to be predicated in (answer to) what a thing is, which are fitted to answer the person inquiring what the proposed thing is, as it is adapted to man, when it is asked what the proposed thing is, to say that he is animal. Moreover it is generic, whether one thing is in the same genus with another or in a different genus, since such a thing falls under the same method with genus, as having discussed that animal is the genus of man, and in like manner of ox, we shall reason that they are in the same genus; if, however, we should show that it is the genus of one of them, but not of the other, we shall reason that these are not in the same genus.

Accident, again, is that which is not any of these, neither definition, nor property, nor genus; yet it is present with a thing, and is that which may possibly be present with some one and the same thing and may not be present, as, to sit may be and may not be present with some one and the same thing, and in like manner whiteness, for there is nothing to prevent the same thing being at one time white and at another not white. Now of these definitions of accident, the second is the better; since when the first is stated, it is necessary in order to understand it, to know previously what definition genus and property are, but the second is self-sufficient for the knowledge per se of what the thing asserted is. To accident also let comparisons of things with each other belong, in whatever way they are derived from accident, as, whether the honourable or the advantageous be preferable, and whether a life of virtue or of enjoyment is the sweeter, and if there happens to be any other assertion similar to these, for in all things of this kind, the question arises as to which the predicate rather happens to belong. Still from these it is manifest that there is nothing to prevent accident sometimes, and with reference to something, becoming property, as to sit being accident, when some one alone sits, will then be a property, but one not sitting alone, it will be a property with reference to those who do not sit, so that nothing prevents accident from becoming property in a certain relation and at a certain time; simply, however, it will not be property.

Nevertheless we must not forget that every thing which is referred to property, genus, and accident will also be adapted to definitions, for by showing that a thing is not present with that alone which is under definition, as in the case of property, or that what is given in the definition is not genus, or that some one of those things stated in the definition is not present, which may also be said in accident, we shall have subverted the definition; so that, on account of the reason given before, all those things which have been enumerated will after a certain manner be definitive. Nevertheless we must not on this account look for one method universal in all things, as neither is it easy to discover this, and if it were discovered it would be altogether obscure and useless to the proposed treatise. But a peculiar method being delivered as to each of the defined genera singly, the discussion of the proposition will be easy from those things which are appropriate to each. Wherefore, as we have before said, we must make a rough division, but of the rest we must join those which are especially appropriate to each, denominating them both definitive and generic. What, however, have been set forth have almost been adapted to each.

We must first of all distinguish about "the same," in how many ways it is predicated; but "the same," to speak in general terms, may appear to be divided triply, since we are accustomed to denominate a thing the same, in number, or in species, or in genus; in number indeed when the names are many but the thing one, as a garment and a vestment, but in species when the things being many are without specific difference, as man with man, and horse with horse, for such things are said to be the same in species as are under the same species: in like manner also, those are the same in genus which are under the same genus, as horse with man. Nevertheless, it may seem indeed that water from the same fountain, being called the same, has a certain difference besides the modes enumerated, yet such a thing must be placed at least in the same arrangement with those, which are in some way or other said to be under one species, for all such things appear to be of a kindred nature and similar to each other, since all water is said to be the same in species with all water, because of the possession of a certain similarity; but water from the same fountain differs in nothing else except that the similarity is greater; wherefore we do not separate it from those which some way or other are said to be according to one species. Confessedly, however, that which is one in number, seems especially to be called the same, by all men; still we usually attribute this in many ways, most properly indeed and chiefly, when "same" is attributed in name or definition, as garment to a vestment, and animal pedestrian biped, to man; secondly, when (it is attributed) in property, as what is susceptible of science to man, and what naturally is carried upwards, to fire; thirdly, when from accident, as that which sits or is musical, to Socrates. For all these would signify one thing in number, and that what we have now said is true, a person may especially learn, from those who change appellations; for frequently when we desire to call some one who is sitting, by name, we change (the appellation), when he to whom we give the order, does not happen to understand, as if he would rather understand from accidents, and we desire him to call to us, the person who is sitting or discoursing , evidently considering it the same thing to signify by name and by accident. Let therefore "same" be triply divided, as we have said.

That disputations are composed from the things mentioned before, and through these, and pertain to these, we have the first evidence through induction, since if any one considers each of the propositions and problems, it will appear to have originated either from definition, or from property, or from genus, or from accident. Another evidence however is by syllogism, for it is necessary that every thing which is predicated of a certain thing, should either reciprocate with that thing or not. And if indeed it reciprocates it will be definition or property, since if it signifies what a thing is, it is definition, but if it does not signify it, it is property, for this was property, viz. that which reciprocates indeed, but does not signify what a thing is. If however it does not reciprocate with the thing, it either is one of those which are predicated in the definition of the subject, or it is not, and if it is one of those predicated in the definition it would be genus or difference, since definition consists of genus and differences, but if it is not of those predicated in definition, it would be evidently accident, for that was said to be accident which is neither definition, nor genus, nor property, yet is present with a thing.

We must next define the genera of the Categories, in which the above-named four (differences) are inherent. Now these are ten in number; what a thing is, quantity, quality, relation, where, when, position, possession, action, passion, for accident, and genus, and property, and definition will always be in one of these categories, since all propositions through these signify either what a thing is, or quality, or quantity, or some other category. Moreover, it is evident from these that he who signifies what a thing is, at one time signifies substance, at another quality, and at another some other category. For when man being proposed, he says that the thing proposed is man or animal, he says what it is, and signifies substance; but when white colour being proposed, he says that the thing proposed is white or colour, he says what it is, and signifies quality. So also, if when the magnitude of one cubit is proposed, he says that what is proposed is a cubit in size, he will say what it is, and will signify quantity, and so of the rest, for each of these, both if it be itself predicated of itself, and if genus (be predicated) of it, signifies what a thing is. When however (it is spoken) of another thing, it does not signify what it is, but quantity or quality, or some other category, so that the things about which and from which arguments (subsist), are these and so many; but how we shall take them, and by what we shall be well provided with them, we must declare hereafter.

In the first place then, let us define what is a dialectic proposition, and what a dialectic problem, for we must not suppose every proposition nor every problem as dialectic, since no one in his senses would propose that which is assented to by no one, nor would he advance as a question what was palpable to all, or to most men, for the latter does not admit of a doubt, but the former no one would admit. Indeed a dialectic proposition is an interrogation, probable either to all, or to the most, or to the wise; and to these, either to all or most, or to the most celebrated, it is not paradoxical, as any one may admit what is assented to by the wise, if it be not contrary to the opinions of the multitude. Dialectic propositions however are both those which resemble the probable and which are contrary to those which appear probable, being proposed through contradiction, and whatever opinions are according to the discovered arts. For if it be probable that there is the same science of contraries, it would also appear probable that the sense of contraries is the same, and if the grammatical art be one in number, that there is one art also of playing on the pipe, but if there are many grammatical arts, there will also be many piping arts, for all these things seem to be similar and akin. So also those things which are contrary to probabilities, being proposed according to contradiction, will appear probable, for if it is probable that we ought to benefit friends, it is also probable that we ought not to injure them. Nevertheless, that we ought to injure friends is contrary, but that we ought not to injure them is contradictory; so also if we ought to benefit friends, we ought not to benefit enemies; but this also is according to the contradiction of contraries, since the contrary is that we ought to benefit enemies, and in like manner in the case of other things. Still the probable will appear in comparison to be the contrary about the contrary, as, if we ought to benefit friends, we ought also to injure enemies. To benefit friends however may appear contrary to injuring enemies, yet whether it is truly so or not, will be shown in what we say about contraries. Notwithstanding, it is apparent that whatever opinions also are according to the arts, are dialectic propositions; since any one would admit those things, which are assented to by persons conversant with such subjects, as in matters of medicine, that the physician (is to be assented to), the geometrician in geometrical concerns, and similarly of others.

The dialectic problem is a theorem tending either to choice and avoidance, or to truth and knowledge, either per se or as co-operative with something else of this kind, about which the multitude either hold an opinion in neither way, or in a way contrary to the wise, or the wise to the multitude, or each of these to themselves. Now some problems it is useful to know, for the purpose of choice or avoidance, as whether pleasure is eligible or not, but others for knowledge only, as whether the world is everlasting or not, some again by themselves, for neither of these purposes, yet do they co-operate to something of this kind, since there are many things which we do not desire to know for themselves, but for the sake of others, in order that through these we may know something else. Moreover, those are problems also, of which there are contrary syllogisms (for they admit a doubt, whether they are so and so, because of there being credible arguments in both respects). And those about which we have no argument from their being vast, conceiving it difficult to assign their cause, e. g. whether the world is everlasting or not, for any one may investigate such things as these.

Let then problems and propositions be distinguished as we have said: a thesis, on the other hand, is a paradoxical judgment of some one celebrated in philosophy, as that contradiction is impossible, as Antisthenes said, or that all things are moved, according to Heraclitus, or that being is one, as Melissus asserted, for to notice any casual person setting forth contrarieties to (common) opinions is silly. Or (a thesis is an opinion) of things concerning which we have a reason contrary to opinions, as that not every thing which is, is either generated or perpetual, as the sophists declare, since (they say) that a musician is a grammarian, though he is neither generated nor eternal, for this, even if it be not admitted by any one, may appear to be from possessing a reason.

A thesis then is also a problem, yet not every problem is a thesis, since some problems are of such a kind, as that we form an opinion about them in neither way; but that a thesis is also a problem is evident, as it is necesary from what we have said, either that the multitude should be at variance with the wise about the thesis, or one or other of these with themselves, since a thesis is a certain paradoxical judgment. Now almost all dialectical problems are called theses, let it, however, make no difference how they are called, as we have not thus divided them from a desire to fabricate names, but that we may not be ignorant what are their real differences.

Still we need not consider every problem nor every thesis, but that which any one may be in doubt about, who is in want of argument and not of punishment or sense, for those who doubt whether we ought to worship the gods and to love our parents or not, require punishment, but those (who doubt) whether snow is white or not, (need) sense. Nor (need we discuss those things) of which the demonstration is at hand, nor those of which it is very remote, for the one do not admit of doubt, but the other, of greater (doubt) than accords to (dialectic) exercise.

These things then being determined, we must distinguish how many species of dialectic arguments there are. Now one is induction, but the other syllogism, and what indeed syllogism is, has been declared before, but induction is a progression from singulars to universals, as if the pilot skilled in his art is the best, so also is the charioteer, and generally the skilful is the most excellent about each thing. Nevertheless, induction is more calculated to persuade, is clearer, and according to sense more known, and common to many things; but syllogism is more cogent, and efficacious against opponents in disputation.

Let then the genera about which, and from which, arguments subsist be defined, as we have stated before, but the instruments by which we shall be well provided with syllogisms are four; one to assume propositions, the second to be able to distinguish in how many ways each thing is predicated, the third to discover differences, and the fourth the consideration of the similar. In a certain way indeed there are three propositions of these, since it is possible to make a proposition as to each of them, as that the beautiful, or the sweet, or the profitable is eligible, and that sense differs from science, in that he who loses the latter may regain it; but this is impossible with the other, and that the wholesome has the same relation to health as what produces good constitutional habit, to a good habit of constitution. Now the first proposition is derived from that which is predicated in many ways, but the second from differences, and the third from similars.

Propositions then must be selected in as many ways as there has been definition about proposition, either choosing the opinions of all, or those of most, or those of the wise, and of these either of all, or of most, or of the most celebrated, or opinions contrary to the apparent, and whatever are according to arts. Yet it is necessary to propose according to contradiction those which are contrary to the apparently probable, as we observed before; but it is useful to produce them by selecting, not only those which are probable, but those also which are like these, as that there is the same sense of contraries, (for there is the same science,) and that we see by admitting, not by emitting, somewhat, as it is thus also with the other senses, since we both hear from admission and not from emission of something, and also taste, and similarly with the rest. Again, whatever are seen in all or in most things, we must take as principle and apparent theses, since persons lay down these who do not see, at the same time, in what thing it does not happen so. We must also select from written arguments, but descriptions must be made supposing separately about each genus; as about good or about animal, and about every good, beginning from what it is; we must also note besides, the several opinions, as that Empedocles said there are four elements of bodies, for any one would admit what had been asserted by some celebrated man.

But to speak comprehensively, there are three parts of propositions and of problems; for some propositions are ethical, others physical, but others logical. The ethical then are such, as whether it is right to obey parents rather than the laws, if the two are discordant; the logical, as whether there is the same science of contraries or not; and the physical, whether the world is perpetual or not; the like also occurs in problems. Still it is not easy to explain by definition, what the quality of each of the above-named is, but we must endeavour to know each of them from habit, which arises from induction, addressing our attention, according to the before-mentioned examples.

With regard then to philosophy, we must discuss these according to truth; but as to opinion, dialectically; still we must assume all the propositions as universal as possible, and make many one, as that there is the same science of opposites, afterwards that there is of contraries, and also of relatives. In the same manner we must divide these again, as long as it is possible to divide them, as that (there is the same science) of good and of evil, and of white and black, of the cold and the hot, and likewise of other things.

Concerning proposition then, what has been stated will suffice, but as to how many ways (a thing may be predicated), we must discuss not only such things as are predicated in a different manner, but also we must endeavour to give their reasons; as not only that justice and fortitude are called good in one way, but what conduces to a good habit of body and to health in another way, but also that some things (are called so) from being certain qualities, but others from being effective of something, and not from themselves being certain qualities, and indeed in a similar manner in other things.

Whether however a thing is predicated multifariously, or in one way in species, we must investigate through these. First, we must consider in the contrary, if it is multifariously predicated, whether it differs in species or in name, for some things immediately differ even in names, as the grave is contrary in voice to the sharp, but in magnitude the obtuse. Therefore it is clear that the contrary to the sharp is predicated multifariously, but if this be so, the sharp also is, for according to each of these, the contrary will be different, since the same sharp will not be contrary to the obtuse and to the grave, but the sharp will be contrary to each. Again, to the heavy in voice, the sharp is contrary, but in weight, the light, so that the heavy is predicated multifariously since the contrary also is. Likewise to the beautiful in an animal, the ugly, but in a family, the depraved (is contrary), so that the beautiful is equivocal.

In some, indeed, there is no dissonance in the names, but the difference in them is at once palpable in species, as in white and black, for voice is said to be clear and obscure in the same manner as colour. In these, then, there is no dissonance in names, but their difference is at once evident in species, for colour and voice are not similarly called clear, and this is also evident from sense, for of things which are the same in species, the sense is the same; but we do not judge the lightness which is in voice, and that which is in colour, by the same sense, but one by sight, and the other, by hearing. So also the sharp and the obtuse in fluids and magnitudes, the one indeed by touch, the other by taste, since neither are these dissonant in names, neither in themselves nor in the contraries, for what is obtuse is contrary to each.

Again, we must consider if there is any thing contrary to the one, but nothing simply to the other; as, to the pleasure from drinking, the pain from thirst is contrary; but to that which arises from contemplating, that the diameter of a square is incommensurable with its side, there is nothing (contrary), wherefore pleasure is predicated multifariously. To hate, also, is contrary to the love which is mental, but nothing to that which subsists according to bodily energy, wherefore it is evident that to love, is equivocal. Besides, we must consider the media, if there is a certain medium of some, but not of others, or whether there is of both, yet not the same, as of white and black, in colour, the dark brown; but in voice, there is no medium, unless it be the hoarse, as some say that a hoarse voice is the medium; so that white is equivocal, and black in like manner; yet more, whether there are many media of some things, but one of others, as in the case of white and black; for in colours, there are many media, but in voice, one, viz. the hoarse.

Again, in that which is contradictorily opposed, we must consider if it is predicated multifariously, for if this is multifariously predicated, the opposite to this also will be enunciated multifariously; thus, not to see, is predicated in many ways; in one, not to have sight; in another, not to energize with the sight. Now if this is multifariously, to see, must necessarily be multifariously predicated; for to each (signification of the verb) not to see, there will be something opposed, thus to the not possessing sight, the possession of it, and to the not energizing with the sight, the energizing with it.

Further, we must remark this, in the case of those things, which are predicated according to privation and habit; for if the one, is multifariously predicated, the other is, also; thus, if to perceive, is predicated multifariously, both according to the soul and according to the body, to be deprived of sense, will be multifariously predicated, i. e. both according to the soul and the body. Nevertheless, that the particulars now mentioned, are opposed according to privation and habit, is evident, since animals are naturally adapted to possess each of the senses, viz. both according to the soul and according to the body.

We must look also to the cases, for if "justly" is predicated multifariously, "the just" also, will be multifariously predicated; for the just subsists according to each of those which are justly, thus if justly is predicated, both of judging according to one's own opinions, and also in a proper manner, the just is similarly. Likewise, if the healthy is multifariously, the healthily also, will be spoken multifariously, as if that is called "healthy," which produces, preserves, and signifies health, the "healthily" also, will be predicated either productively, or preservingly, or significantly. And in like manner in other things, when (the noun) itself is multifariously predicated, the case also derived from it, will be spoken in many ways, and if the case (the noun) itself besides.

We must regard too, the genera of the categories, as to name, whether they are the same in all things, since if they are not the same, it is evident that what is predicated, is equivocal; thus good in food is what produces pleasure, in medicine, what produces health, in the soul, to be of a certain quality, as temperate, or brave, or just, similarly also in the case of man. Sometimes indeed it is "the when," as the good in opportunity, for that is called good, which is in season: frequently also quantity, for instance, the moderate, for the moderate also is called good, so that good is equivocal. Likewise clearness in respect of body, is colour, but in voice, that which may easily be heard, and in like manner the acute, for the same, is not predicated in all things, after the same manner, for a rapid voice is called acute, as musicians say, who are conversant with numbers; but an angle is acute, which is less than a right angle, and a sword is acute, which has a sharp point.

We must also notice the genera, of those things which are under the same name, whether they are different and not subaltern, thus ὄνος is both an animal and a vessel, since the definition of them according to the name, is different, for the one will be said to be a certain kind of animal, but the other a certain kind of vessel. If however the genera are subaltern, the definitions need not be different, as of a crow, both animal and bird are the genus, when therefore we say, that a crow is a bird, we also say, that it is a certain kind of animal, so that both genera are predicated of it; likewise also when we say that a crow is a winged biped animal, we say that it is a bird, and thus then both the genera are predicated of the crow, and also the definition of them. This nevertheless does not occur in genera which are not subaltern, since neither when we speak of a vessel, do (we speak of) an animal, nor when (we speak of) an animal, (do we mean) a vessel.

Not only indeed must we observe whether the genera of the thing proposed, be different and not subaltern, but also in regard to the contrary, since if the contrary is predicated in several ways, it is evident that the proposition will be so too.

It is useful also, to regard the definition produced from the composite, as of a white body and white voice; for the property being taken away, it is necessary that the same definition should be left. Now this does not occur in equivocals, for instance, in the things now spoken of, for the one, will be body having such a colour, but the other, will be an audible voice; body, then, and voice being taken away, what remains is not the same in each, at least it would be necessary if white, were synonymous, that what is predicated in each (definition), should be (the same).

Frequently also in the definitions themselves, the equivocal, which is consequent, escapes us, wherefore, we must look to the definitions. Thus, if any one were to say, that what is significant and productive of health, is that which is symmetrically disposed with respect to health, we must not leave off, but consider what he calls symmetrically, in each, as if the one, were to be of such a kind, as to produce health, but the other, such as to signify, what is the quality of the habit.

Moreover, (we are to examine) whether they may not be compared according to the more, or similarly, as a light voice, and a light garment, and a sharp flavour, and a sharp voice, for these are neither called light nor sharp similarly, nor one, more than the other. So that the light, and the sharp, are equivocal, for every synonym is capable of comparison, since it will either be predicated similarly, or one more than the other.

Since however of things heterogeneous and not subaltern, the differences are also different in species, as of animal and science, (for the differences of these are diverse,) consider whether those things, which are under the same name, are the differences of different, and not of subaltern genera, as the acute (is the difference) of voice and magnitude, for voice, differs from voice, in acuteness, likewise also one mass, from another, so that the acute is equivocal, for these are the differences of diverse, and not of subaltern, genera.

Again, (observe) whether of things under the same name, there be divers differences, as of the chroma which belongs to bodies, and of that which is in melodies, for of that which belongs to bodies, the differences are, that which diffuses, and that which condenses, the vision, but these are not the same differences of that which is in melodies, so that chroma is an equivocal word, for there are the same differences of the same things.

Once more, since species is not the difference of any thing, notice of those which are under the same name, whether one is species, but the other, difference, as bodily clearness is a species of colour, but vocal (clearness) is a difference, since voice differs from voice, in being clear.

Concerning therefore what is multifariously predicated, we must consider it through these and such as these; but the differences we must investigate in the genera themselves with respect to each other, as what difference there is between justice and fortitude, prudence and temperance, (for all these are from the same genus, virtue,) and of those which do not differ very much, one from the other, as in what, sense, differs from, science, since in things which are very different, the differences are altogether palpable.

We must consider similitude in the case of things of different genera, (thus) as one thing is to another, so is another to another, for instance, as science to the object of science, so is sense to the object of sense, and as one thing in a certain other thing, so is another thing in another, e. g. as sight in the eye, so is intellect in the soul, and as tranquillity in the sea, so is serenity in the air. But most of all, it is necessary to be practised, in things vastly diverse, for we may easily perceive similitudes in the rest. Besides, we must also consider those things which are in the same genus, whether something identical is present with all, as for instance, with man, and horse, and dog; since so far as something identical is present with them, so far are they similar.

To have considered in how many ways a thing may predicated, is useful for perspicuity, (as any one can better know what he admits, when it is clearly explained in how many ways it may be predicated,) and for the construction of syllogisms against the thing itself, and not (merely) against the name. For when it is dubious in how many ways it is predicated, he who answers, and he who questions, may possibly not direct their attention, to the same thing, but when it is explained in how many ways it is predicated and with what object a person admits it, the questioner would appear ridiculous if he did not frame his argument against this. But it is also useful that we may not be deceived (ourselves) by paralogism, and may deceive another by it, since when we know in how many ways predication occurs, we can never be deceived by paralogism, but we shall know if the questioner does not argue against the same thing, and we ourselves, when questioning, shall be able to deceive by paralogism, except the respondent happens to know, in how many ways predication occurs. Nevertheless, this is not possible in all cases, but when of things multifariously predicated, some are true, but others false; this mode however is not appropriate to dialectic, wherefore a thing of this kind, must be altogether avoided by dialecticians, viz. arguing against a name, unless any one should be otherwise incapable of discussing the proposition.

Notwithstanding, it is useful to discover differences, in order to (construct) syllogisms of the same, and of the different, and also to the knowledge of what each thing is. That it is useful for syllogisms about the same, and the different, is clear; for when we have discovered the difference of the things proposed, of whatever kind it may be, we shall have shown that they are not the same, (and it is useful) for the knowledge of what a thing is, because we are accustomed to separate the proper definition of the essence of each thing, by the peculiar differences of each.

On the other hand, speculation upon the similar, is useful for inductive reasons, and for hypothetical syllogisms, and for the statement of definitions. For inductive reasons then, because by the induction of similar particulars, we deem it proper to infer the universal, since it is not easy to form induction, when we are ignorant of similars. (It is useful also) for hypothetical syllogisms, because it is probable that as a thing subsists in one of those which are similar, so also it does in the rest, so that in order that we may discuss any of them sufficiently, we should previously acknowledge, that as a thing is in these, so also is its condition in the subject proposed; but when we have demonstrated that, we shall also have proved the proposition by hypothesis, for we have framed a demonstration, upon the supposition that as a thing is in these, so it is also, in the case of what is proposed. Again, for the statement of definitions (it is useful), since being able to comprehend what in each thing is identical, we shall not be in doubt as to what genus the thing proposed ought to be referred, in definition; for of those which are common, what is especially predicated in (the question) what a thing is, will be the genus; in like manner in those which are vastly different from each other, the contemplation of the similar is useful for definitions, as that tranquillity in the sea, is the same thing as serenity in the air, (for each of them is quiet,) and that a point in a line (is identical) with unity in number, for each is a principle. Wherefore by assigning the common genus in all things, we shall appear not to define in a manner foreign (from the subject), and indeed almost those who define, are accustomed thus to explain, for they say that unity is the principle of number, and that a point is the principle of a line; it is evident then that they refer the genus of both to what is common.

The instruments therefore by which syllogisms are constructed, are these; but the places, for which what we have said, is useful, are those (which follow).

Of problems, some are universal but others particular, the universal then, as that all pleasure is good, and that no pleasure is good, but the particular, as that a certain pleasure is good, and a certain pleasure is not good. To both genera, however, of problems, those things are common which universally construct and subvert, for having shown that a thing is present with every, we shall also have proved that it is present with a certain individual, and in like manner, if we have shown that it is present with no individual, we shall also have proved it not present with every. We must first speak, then, of those which are universally subversive, both because such are common to universal and particular (problems), and because men rather introduce theses in the affirmative than in the negative, but the disputants subvert them. Nevertheless, it is most difficult to convert an appropriate appellation (derived) from accident, for (to be inherent) partly, and not universally, it is possible to accidents only, since it is necessary to convert from definition, property, and genus, as if it is present with a certain thing to be an animal, pedestrian, biped, it will be true for the person who has converted it, to say, that it is an animal, pedestrian, biped. Likewise from genus, for if it is incident to a thing to be an animal, it is an animal; and it is the same with property, for if it is present with any to be capable of grammar, it will be capable of grammar, since nothing of these can be partly present or not present, but simply present or not present. Yet there is nothing to prevent accidents from being partly present, for instance, whiteness or justice, so that it is not enough to show that whiteness or justice is inherent, in order to show that a man is white or just, since it is doubtful, because he may be partially white or just, so that conversion is unnecessary in accidents.

Again, we must determine the errors occurrent in problems, that they are two, either from false assertion, or a departure from the established mode of speaking. For both false assertors err, from saying that what is not present, is present with a certain thing, and those who call things by foreign names, as a plane tree a man, transgress the established nomenclature.

One place then is, to consider whether he (the respondent) has given as an accident, that which is inherent, according to some other mode; which error, indeed, especially obtains about genera, as if some one should say, that it was accidental to whiteness to be a colour, since it is not accidental to whiteness to be a colour, but colour is its genus. Therefore, it is possible that he who lays down a thesis, may define according to denomination (the genus as an accident), e. g. that it is accidental to justice to be a virtue; frequently, however, without definition, it is evident that he has given the genus as an accident, as if any one should have said, that whiteness is coloured, or that walking is moved, for the predication of species is paronymously asserted from no genus, but all genera are predicated of species synonymously, since species receive the name and definition, of genera. Whoever, therefore, says that whiteness is coloured, has neither explained it as genus, since he has spoken paronymously, nor as property, nor as definition, since definition and property are present with nothing else, while many other things are coloured, as wood, stone, man, horse; wherefore he evidently gives it as accident.

Another (topic) is, to regard those with which, either all or none, a thing is said to be present, and to consider according to species and not in infinites, (individuals,) for the investigation (will be) more in the way and in fewer things. Still we must consider and begin from first things, and then (proceed) as far as individuals, for instance, if a man said that there is the same science of opposites, we must consider if there is the same science of relatives, of contraries, and of those which are enunciated according to privation and habit, and according to contradiction, and if it should not yet be evident in these, we must divide them again as far as individuals, as whether (there is the same science) of the just and the unjust, or of the double and the half, or of blindness and sight, or of entity and nonentity. For if it should be proved that there is not the same in respect of a certain thing, we shall have subverted the problem, likewise also if it should be present with none. Now this place converts to confirmation and refutation, for if, when they have introduced division, it should appear (present) with all, or with many, things, it must be required to admit it universally, or to object some (instance) wherein it is not so, and if (the opponent) does neither of these, he will appear absurd from not conceding it.

Another (topic) is, to make definitions, both of accident and of that to which it is accidental, either of both severally, or of one of them, then to consider whether any thing has been assumed as true, which is not true, in the definitions; thus if the (problem) is, that we can injure God, (we must consider) what it is, to injure, for if it be, to hurt voluntarily, it is evident that God cannot possibly be injured, since it is impossible that God can be hurt. Again, if the worthy man is envious, who is the envious, and what is envy, (must be considered,) for if envy be pain at the apparent success of some worthy person, it is evident that a worthy man is not envious, for if so, he would be depraved, and if the man prone to indignation be envious, (we must explain) who each of these is, for thus it will be evident whether what is said is true or false, e. g. if he is envious who is grieved at the success of the good, but he is prone to indignation who is grieved at the success of the bad, it is clear that the envious will not be the indignant man. We must also assume definitions, instead of the names in definitions, and not desist until we arrive at what is known; since often the question is not yet clear, when, indeed, the whole definition has been given, but it becomes evident, if the definition is given, instead of some name placed in the definition.

Moreover, the problem must be changed into a proposition and then objected to, for the objection will be an argument against the thesis: this place, indeed, is almost the same as seeing, with what, either all or none, a thing is said to be present, but it differs in the mode.

Further, we must define what kind of things we ought, and what we ought not, to denominate as the multitude do, for this is useful both for confirmation and subversion, as that things are to be called by the same names as the multitude use, but that we are no longer to attend to the multitude, as to the quality of things, whether they be such or such. For instance, that is to be called salubrious, which is productive of health, as the multitude say, but whether the thing proposed be productive of health or not, is no longer to be decided by what the multitude, but by what the physician declares.

Moreover, if a thing be multifariously predicated, but is laid down as inherent, or as noninherent, we must prove one of the things multifariously predicated, if we cannot prove both. This must be used, however, in those things which are latent, for if what is multifariously predicated is not latent, the opponent may object, that what he is in doubt about, is not the subject of dispute, but something else. This topic, indeed, converts both for confirmation and subversion, for when we desire to confirm we shall show that one is inherent, if we cannot both; but when we subvert, we shall show that one is not inherent, if we cannot both. Nevertheless, there is no need for the subverter to dispute from compact, neither if a thing be said to be present with every individual, nor if it be said to be so with none, since if we show that it is not present with any individual whatever, we shall have subverted its being with every individual, likewise also if we should prove it present with one, we shall have subverted its presence with nothing. Still, in confirming, we must previously acknowledge, that if it is present with any whatever, it is present with every thing, if the axiom be probable, since it is not enough to discourse about one thing, in order to prove that it is present with every thing, as if the soul of man is immortal, that every soul is immortal, wherefore, it must be previously taken for granted, that if any soul whatever is immortal, every soul also is immortal. This, however, is not always to be done, but when we cannot supply one common reason in all, as a geometrician (proves by one common reason, that a triangle has angles equal to two right).

Yet if a thing is not latent, being predicated in many ways, we must subvert and confirm, having distinguished in how many ways it is predicated; thus, if the becoming is the advantageous or the beautiful, we must try to confirm or subvert, both about the proposed (problem), e. g. that it is beautiful and advantageous, or that it is neither beautiful nor advantageous. Still if we cannot prove both, we must prove one, of them, showing that the one is, but the other not; but the reasoning is the same, though there should be more members in the division.

Again, (we must consider) those things which are not equivocally predicated in many ways, but in some other way, thus science is one of many, either as belonging to the end, or to that which pertains to the end, as medicine (is the science) of producing health, and of prescribing diet, or as belonging to both ends, as of contraries there is said to be the same science, (since the one) is no more an end than the other, or as belonging to that which is per se, and to that which is accidental, as (we know) per se that a triangle has angles equal to two right, but according to accident, that it is equilateral, for because it happens to an equilateral triangle to be a triangle, according to this we know that it has angles equal to two right. If then it is by no means possible that there should be the same science of many things, it is clearly altogether impossible, or if in a certain respect it is possible, it is clear that it is possible. Nevertheless, we must distinguish in how many ways it is useful; for instance, if we desire to confirm we must introduce such things as are possible, and we must divide them into those only which are useful to confirmation; but if we would subvert, (we must introduce) such things as are impossible, and omit the rest. This too must be done in these, when it is latent in how many ways they are predicated, that this also belongs to that, or does not belong, must be confirmed from the same places; as that this science is of this thing, either as belonging to the end, or to those things which pertain to the end, or as to those which are accidental, or on the other hand, that a thing is not according to any of the above-mentioned modes. The same reasoning also subsists about desire and such other things as are said to belong to many, for desire belongs to this thing either as to the end, as to health, or as to those things which pertain to the end, as to the taking medicine, or as to that which is from accident, as in wine, he who loves sweetness (desires wine), not because it is wine, but because it is sweet, since he desires sweetness per se, but wine accidentally, since if it should be sour, he no longer desires it, therefore he desires it from accident. This place however is useful in relatives, for almost all such things as these, belong to relatives.

Again, a change must be made into a name more known, as, for instance, the clear instead of the accurate in notion, and the love of employment instead of being engaged in various occupations, for the assertion being more known, the thesis is more easily opposed. This place also is common to both confirmation and subversion.

In order however to show that contraries are present with the same thing, it is necessary to attend to the genus; thus if we desire to prove that there is rectitude and error about sense, since sensibly to perceive, is to judge, but it is possible to judge rightly and not rightly, about sense also, there will be rectitude and error. Now, then, from the genus the demonstration is concerning the species, since to judge is the genus of sensible perception, for he who sensibly perceives, in some way judges. Again, from species to genus, for whatever things are present with species are also with genus, as if science is bad and good, disposition also is bad and good, for disposition is the genus of science. The former place therefore is false indeed for confirmation, but the latter is true, since it is not necessary that whatever things are present with genus, should also be present with species, since animal is winged and quadruped, but man is not, yet whatever things are present with species, are necessarily also with genus, for if man is good, animal also is good. Still for subversion, the former is true, but the latter false, as whatever are not present with genus, neither are with species, but it is unnecessary that whatever are not with species, should not be present with genus.

Notwithstanding, since it is requisite that of what things genus is predicated, some species also should be predicated, and whatever things possess genus, or are paronymously denominated from genus, have necessarily a certain species, or are paronymously demonstrated from some species, as if science is predicated of some certain thing, grammar also, or music, or some other science, will be predicated (of it); and if any one has science, or is paronymously denominated from science, he will also possess grammar, or music, or some other science, or will be paronymously called from some one of them, as, for instance, a grammarian or musician;—if then anything should be laid down which is in any way denominated from genus, as that the soul is moved, we must consider whether it is possible for the soul to be moved according to any species of motion, as to be increased, or corrupted, or generated, or such other species of motion. For if by none (may it be moved), it is evident that it is not moved: this place also pertains in common to both subversion and confirmation, for if it is moved according to any species, it is evident that it is moved, and if according to no species, it is evidently not moved.

He however who is not well provided with arguments about the thesis, must consider from the definitions, either real or apparent, of the proposed thing, and if he cannot from one, (definition, he must obtain an argument) from many, for it will be easy to argue when they have defined, since opposition to definitions is easier.

We must also consider in the proposed (problem) to what thing it belongs, or what will necessarily be if the proposition subsists. The person who wishes to confirm, must consider to what the proposition will belong, (for if that be shown to exist, the proposition will also have been proved,) but he who wishes to subvert, (must consider) what will be the consequence if the proposition subsists, for if we can show that the consequent to the proposition does not subsist, we shall have subverted the proposition.

Besides, we must attend to time if it is any where discrepant, as if a person said that what is nourished, is of necessity increased, for animals are always nourished, yet do not always increase. Likewise, if he said that to know scientifically, is to remember, for the one belongs to past time, but the other to the present and the future, for we are said to know scientifically things present and future, as that there will be an eclipse, but it is impossible to remember any thing except the past.

It is also a sophistical place, to bring (the adversary) to that, against which we are well provided with arguments, and this will sometimes indeed be necessary, at others, appear to be so, but sometimes neither apparent, nor necessary. Now it is necessary, when the respondent, denying some one of those things which are useful to the thesis, the arguments are directed against this, which happens to be a thing of that kind, against which it is possible to abound with arguments. In like manner, when some one by making an abduction to a certain thing, through what is laid down, endeavours to subvert (that thing), for this being subverted, the proposition is also subverted. On the other hand, it appears to be necessary when it seems indeed useful and appropriate to the thesis, yet is not so to that against which the arguments are adduced, whether he who sustains the argument denies, or whether by a probable abduction through the thesis against it, he endeavours to subvert it. The remainder is when that against which the arguments are advanced, is neither necessary nor appears to be so, but it happens that the respondent is sophistically confuted in another respect. We must however be cautious about the last of the above-mentioned modes, for it seems to be altogether remote and foreign from dialectic, wherefore the respondent must not be displeased, but should admit whatever are not useful to the thesis, signifying what do not appear to him to be true, though he admits them; for it happens generally that those who interrogate are more perplexed, when every thing of this kind is admitted, if they do not conclude.

Further, every one who states any thing, in some way states many things, since many are consequent of necessity, upon each; for instance, he who states that man is, states also that animal is, and that animated, and that biped, and that what is capable of intellect and science (are), so that any one of these consequents being subverted, the original proposition also, is subverted. Still we must be careful lest we make a transition to what is more difficult, for sometimes it is easier to subvert the consequent, and at others the proposition itself.

In those things, with which it is necessary one thing alone, should be present, as with man, disease or health, if we are well furnished with arguments against one, that it is present or not, we shall also be well provided against the other. This, however, converts with regard to both, for when we have proved one of them present, we shall have proved that the other is not present, but if we have proved that it is not present, we shall have proved the other present; wherefore the place is evidently useful for both.

Again, we must argue by transferring the name to the meaning, as being more appropriate to assume, than as the name is placed, for instance, (to take) well-animated, not brave, as it is now placed, but (as signifying) one who has his soul well, as also hopeful of good, one who hopes good things, and in like manner, good-fated, one whose demon is good, just as Xenocrates says, that he is happy who has a worthy soul, for that this is each man's demon.

Since, however, some things are from necessity, others subsist generally, but others casually, if what is from necessity is laid down as general, or what is general as from necessity, either itself, or the contrary to what subsists generally, it always affords a place for argument. For if what is of necessity be laid down as for the most part, it is evident that a person states it to be present, not with every individual, when it is, so that he commits an error; also, if he says, that what is for the most part is from necessity, since he states that to be present with every individual which is not; similarly, if he says that the contrary to the general is from necessity, for the contrary to the general is always asserted of the fewer, for instance, if men are generally bad, good men are few, so that he makes a still greater error if he says that men are of necessity good. Likewise, if he should say that what happens casually, is from necessity, or for the most part, for the casual, is neither necessary, nor general; if, however, a person has not defined, whether he says a thing is general, or of necessity, but the thing should subsist as for the most part, it is possible to dispute, as if he had said, it was of necessity, e. g. if he had said, that those without heritage were bad, without defining them (who they are), it might be argued as if he had said (they were so), from necessity.

Moreover, we must consider whether he has placed a thing accidental, as if different, to itself, from the name being different, as Prodicus divided pleasures into joy, delight, and hilarity, for all these are names of the same thing, pleasure; if then any one should say that joy happens to hilarity, he would say that the same thing happens to itself.

Since contraries are united to each other in six ways, but produce contrariety when united in four, we must assume contraries in such a method as may be useful, both to the subverter and constructer. Now that they are involved six ways is clear, for either each will be connected with each of the contraries, and this in a twofold respect, as to act well by friends and ill by enemies, or, on the contrary, to act ill by friends and well by enemies: or when both are about one thing, and this in two ways, as to act well by friends and ill by friends, or well by enemies and ill by enemies: or one thing about both, and this in a twofold respect, as to act well by friends and well by enemies, or ill by friends and ill by enemies.

The first two conjunctions named, do not, indeed, produce contrariety, since to act well by friends is not contrary to acting ill by enemies, as both are eligible and proceed from the same character. Nor is the injuring friends contrary to the benefiting enemies, for both these are to be avoided and proceed from the same character, but what is to be avoided does not seem contrary to what is to be avoided, unless the one is spoken according to excess, but the other according to defect, for excess appears to be of the number of things to be avoided, and similarly also defect. All the remaining four, however, produce contrariety, for to benefit friends is contrary to injuring friends, for they are both from contrary character, and the one is to be chosen and the other avoided. In like manner, also, as to other things, for according to each connexion, the one is eligible, but the other to be avoided, and the one belongs to a worthy, but the other to a depraved character, so that it is clear from what we have said, that many things happen to be contrary to the same thing; for to benefit enemies, and to injure friends, are contrary to benefiting friends, and similarly to each of the others, there will appear two contraries, to those who consider them after the same manner, nevertheless, whichever contrary is useful to the thesis should be assumed.

Moreover, if any thing is contrary to accident, we must see whether it is present with what the accident is said to be present with; for if this is present, that cannot be, since contraries cannot possibly be at the same time with the same thing.

Also whether such a thing has been predicated of any, which existing, contraries must necessarily be inherent; thus if any one said that ideas are in us, for it will happen that they will both be moved and be at rest; also be both sensible and intelligible. For ideas, to those who admit their existence, appear to rest, and to be intelligible; but if they are in us, they cannot be immovable, for since we are moved, it is necessary that all things in us should be moved together with us, it is also clear that they are sensible if they are in us, for through the sense of sight we know the form which is in every thing.

Again, if accident is laid down to which there is a certain contrary, we must consider whether it is also susceptible of the contrary which contains the accident, for the same thing is capable of contraries; thus if any one said that hatred followed anger, hatred would be in the irascible (part of the soul), for anger is there. We must consider then whether the contrary also is in the irascible part, friendship, for if not, but friendship is appetitive, hatred would not follow anger. Likewise, also, if he said that the appetitive part of the soul was ignorant, for it will be capable of science, if indeed it is of ignorance, which does not seem to be the case, that the appetitive part should be capable of science. Whoever therefore subverts, should, as we have said, use this place, but it is not useful to one who confirms that accident is inherent, though it is useful to show that it is possible to be inherent. For when we have shown that it is not susceptible of the contrary, we shall have shown that accident is neither, nor can be, inherent; but if we have shown that the contrary is inherent, or that it is susceptible of the contrary, we shall not yet have shown that accident also is inherent, but it will only be so far proved that it may be inherent.

As oppositions are four, we must consider (whether we can derive an argument) from contradictions, the consequence being inverse both for subversion and confirmation, and we must assume from induction, as if a man is animal, what is not animal is not man, likewise in other things; for here the consequence is inverse, since animal is consequent to man, but what is not animal is not consequent to what is not man, but inversely what is not man is consequent to what is not animal. In all cases then such must be admitted, as if the beautiful is pleasant, the unpleasant is not beautiful, and if this is not, neither will that be; likewise also if the unpleasant is not beautiful, the beautiful is pleasant, wherefore it is clear that the consequence according to contradiction being inverted, converts to both.

In contraries indeed, both the subverter and the constructers must consider, whether the contrary follows the contrary directly, or inversely, but must also assume such things, as far as it is useful, from induction. The consequence then is direct, for instance, to bravery and timidity, for to the one, virtue, but to the other, vice, is consequent, and the eligible follows the one, but what is to be avoided, the other, therefore the consequence of these also is direct, since the eligible is contrary to what is to be avoided, and similarly in other things. But the consequence is inverse, as health indeed follows a good habit of body, but disease does not, a bad habit, but a bad habit of body is consequent to disease, wherefore it is clear that the consequence in these, is inverse. Nevertheless, the inverse rarely occurs in contraries, but in most of them the consequence is direct; if then the contrary follows the contrary, neither directly nor inversely, it is manifest that neither in what is asserted, is the one, consequent to, the other, but if in contraries, in the assertions also, it is requisite, that the one should be consequent to the other.

As in contraries, so also must we consider in privations and habits, except that in privations the inverse does not occur, but the consequence must of necessity always be direct, just as sense follows sight, and privation of sense, blindness, for sense is opposed to the privation of sense, as habit and privation, since one of these is habit, but the other is privation.

Relatives also, we must use in a similar way to habit and privation, for their consequence is direct, as if the triple is multiple, the sub-triple also is sub-multiple, for the triple is referred to the sub-triple, and the multiple to the sub-multiple. Again, if science is opinion, the object of science will also be the object of opinion, and if vision is sense, the visible also, is sensible. It is objected (perhaps), that it is not necessary there should be a consequence in relatives, as we have said, for the sensible is an object of science, but sense is not science, yet the objection does not appear to be true, for many deny that there is science of sensibles. Besides, what has been said is no less useful for (proving) the contrary, as that the sensible is not an object of science, since neither is sense, science.

Again, we must both in subversion and construction, attend to elementary co-ordinates, and to cases, and such things are called co-ordinates, as just things, and a just man, with justice, and courageous deeds, and a courageous man, with courage. Likewise, also, things efficient, and conservative, are co-elementary with that, of which they are efficient, or conservative, as the salubrious, with health, and the productive of a good habit, with a good habit, of body. In the same manner with other things, whence it is usual to call such, coordinates, but cases, are such as justly, and courageously, and healthily, and whatever are spoken after this manner. Those also which are according to cases, seem to be co-ordinate, as justly with justice, and courageously with courage; but all those are called co-ordinate, which are in the same affinity, as justice, a just man, a just thing, justly. It is clear then, that when any one of these which are in the same affinity, is proved good or laudable, all the rest also have been shown so, as, if justice is one of things laudable, the just man, and the just thing, and the justly, are also of the number of things laudable, but justly, and laudably, will be enunciated according to the same case, from the laudable, as justly from justice.

Not only however is the contrary to be considered in what has been said, but also in the contrary, as that the good is not necessarily pleasant, for neither is the evil (necessarily) painful, or if this is, that also is, or so if justice is science, injustice is ignorance, and if justly, is scientifically, and skilfully, the unjustly, is ignorantly, and unskilfully, and if these are not, neither are those, as in the case just now stated, for what is unjustly, would rather appear skilfully, than unskilfully, (done). Now this place has been mentioned before, in the consequences of contraries, for we do not now lay down any thing else, as a principle, than that the contrary follows the contrary.

Moreover, both by the subverter and the constructor, (arguments are to be derived) in generations and corruptions, efficients and destructives. For those things of which the generations are good, are themselves also good, and if they are good, the generations are too; but if the generations are of the number of things evil, the things themselves also are of evil. In corruptions, indeed, it is the contrary, for if corruptions are among the number of things good, the things themselves (corrupted) are evil, but if the corruptions are amongst things evil, the things themselves are good. The same reasoning indeed prevails in the case of efficients and destructives, for those things, of which the efficients are good, are themselves also good, but those, whose destructives are good, are themselves amongst things evil.

Again, (it should be observed,) whether the same thing happens with similars, as if science is one of many, whether opinion also is, and if to possess sight is to see, whether to possess hearing also is to hear, and likewise of the rest, both in the case of the real and of the apparent. This place indeed is useful for both, for if it is so with any similar, it will be also with other similars, but if not with some, neither with the others. Still we must consider both, whether the same occurs in one thing and in many, for sometimes there is a discrepancy; thus, if to know scientifically is to energize with the intellect, to know many things scientifically is intellectually to energize about many things, but this is not true, for we may know much scientifically without energizing the intellect, if then this is not (true), neither is that (which was asserted) in one thing, viz. that to know scientifically is to energize the intellect.

Besides, we must take arguments from the more and less; now there are four places of the more, one is, if the more follows the more, as if pleasure is good, the greater pleasure is the greater good, and if to injure is evil, the greater injustice is the greater evil. This place indeed is useful for both, for if the addition of the accident is consequent upon the addition of the subject, as was stated, it is evident that it happens, but if it is not consequent it does not happen, but this must be assumed by induction. Another place is, when one thing is predicated of two, if it is not present with what it is more probable to be present, neither (will it be) with what (it is) less (probable), and if it is present with what it is less probable to be present, (it is) also with what (it is) more (probable). Again, when two things are predicated of one, if what appears more present is not present, neither will the less, or if that which appears to be less present is present, that which is more (will be). Once more, when two things are predicated of two, if what appears more present with the one is not present, neither will the remainder be with the remainder; or if what appears less present with the other is present, the remainder also (will be) with the remainder.

Again, (there is an argument) from what is similarly present, or appears to be present, triply, just as was said in that, which was more (present), in the three last-mentioned places. For whether one thing is similarly present with two, or appears to be so, if it is not with the one, neither is it with the other, but if it is with the one it will be also with the remainder; or two things similarly present with the one, if the one is not present, neither will the other be, but if the one, (then) also the other. In the same way if two things are similarly present with two, for if one is not present with the other, neither will the remaining one (be) with the remainder, but if the one is present with the other, the remainder (will be) also with the remainder.

It is possible then to argue in so many ways from the more, the less, and the similar; also indeed from addition, if one thing being added to another makes that good or white, which before was not white or good, what is added will be (such) a whiteness or good, as in fact it causes the whole to be. Further, if a certain thing being added to what is inherent, makes it more such than it was, itself also will be of a similar kind; and the same with other things. Still this (place) is not useful in all cases, but in those, in which there happens to be an excess of the more. This place too, does not convert for the purpose of subversion, for if what is added does not produce good, it is not yet manifest whether itself be not good, since good added to evil, does not of necessity render the whole good, nor white (added) to blackness.

Again, if a thing is said to be more and less, it is likewise simply, for what is not good nor white, will neither be said to be more or less good or white, for evil is not more or less good, than any thing, but will be said to be more or less evil. Yet neither does this place convert for the purpose of subversion, since many things which are not said to be more, subvert simply, for man is not called more and less, yet not on this account is he not man.

In the same manner we must pay attention to that which subsists according to something, and at some time, and in some place; for if it is possible as to something, it is also simply possible, and in like manner the when or the where, for what is simply impossible, is neither possible as to any thing, nor any where, nor at any time. It is objected (perhaps) that worthy men are naturally (so), as to a certain thing, for instance, liberal or temperate, but simply they are not naturally worthy. Likewise it is possible at some time that something corruptible may not be corrupted, but simply it is impossible that it should not be corrupted: in the same way also it is beneficial to use a certain kind of diet some where, for instance, in unhealthy places, but simply it is not beneficial. Moreover, in a certain place, it is possible for one only to be, but simply it is not possible that one only should be; in the same way also at a certain place, it was good to sacrifice a father, e. g. among the Tribali, but simply it is not good. Now does not this indeed signify not a certain place, but to certain people? for it makes no difference where they may be, since every where it will be a noble action with them, (as) Tribali. Again, at some time it is beneficial to take medicine, as when a man is ill, but simply it is not (beneficial), may we not say that neither does this signify a certain time, but refers to one disposed in a certain way, for it does not signify at all when (it is done), if only he be thus disposed. But that is simply, which, when nothing is added, you may declare to be good or the contrary, e. g. you would not say that to sacrifice a father is good, but that it is good amongst certain persons, it is not therefore simply good. On the contrary, you will say that to reverence the gods is good without any addition, for it is simply good; hence that which without any addition appears to be good, or base, or any thing else of the kind, will be said (to be so) simply.

BOOK III

From these things, we must consider which of two or more, is the more eligible or better, and this is first to be determined, that we do not make those the subjects of consideration, which are very remote and greatly differ from each other, (since no one doubts whether happiness or wealth is preferable,) but those which are near, and about which we entertain a doubt, to whether of them, "more" should be added, because we see no superiority of one to the other. Now in these it is clear, that one or more excellencies being shown, the reasoning faculty will grant, that this is more eligible whichever of them happens to excel.

First, then, that which is longer in duration or is more certain, is more eligible, than that which is less such; and that which a wise or good man would rather choose, or upright law, or the studious about each would prefer, so far as they are such; or the scientific in each genus; or whatever the great number, or all; (as in medicine or in carpentering, what the greater number of physicians, or all, would choose;) or such things, in short, as most or all things (choose), for instance, good, for all desire what is good. Yet we must bring what shall be said, to that which is useful, but simply the better and more eligible, is that which is according to the better science, but to a certain one, that which is according to his proper science.

Next, whatever is in genus (is more eligible) than that which is not in genus, for instance, justice than a just man, for the one is in genus, that is, in good, but the other, not, and the one is what is good, but the other not, since nothing is said to be what genus is, which does not happen to be in genus, thus a white man, is not what colour is, and similarly of the rest.

That, also, which is eligible for itself, is preferable, to what is eligible for the sake of something else, as to be well, is preferable to being exercised, for the one is eligible for itself, but the other for something else. Also what is per se, than what is accidental, as that friends, rather than that enemies, should be just, for the one is eligible per se, but the latter accidentally, since we wish our enemies to be just, from accident, that they may not injure us. This, however, is the same with what is prior to it, but it differs in the mode, as we desire our friends, to be just, for their own sake, even if nothing should happen to us, and they should be in India, but our enemies, for something else, viz. that they may do us no injury.

The cause also, per se, of good, is preferable to the accidental cause, as virtue than fortune, for the one, is the cause of good, per se, but the other accidentally; also, if there is any thing else of the kind. It will be the same, too, in the contrary (to the eligible), for what is per se, the cause of evil, is more to be avoided, than the accidental cause, for instance, vice and fortune, for the one is evil per se, but fortune from accident.

The simple good, again, is more eligible than that which is (so) to a certain person, as to be well than to be cut, for the one is simply good, but the other to some one who requires to be cut. Also what is naturally (good, is preferable) to what is not naturally (so), as justice than a just man, since the one is by nature, but the other is acquired. That also is preferable, which is present with the better and more honourable, as (that which is present) with God, than with man, and with the soul, than with the body. The property, also, of the better is better than that of the worse, e. g. that of God than that of man, for according to what are common in both, they do not differ from each other, but the one excels the other in properties. Whatever, also, is in the better, or the prior, or the more honourable, is better, as health than strength and beauty, for the one is in the moist, and the dry, and the hot, and the cold, in short, (in those things) whereof primarily the animal consists, but the other in things posterior, for strength is in nerves and bones, but beauty seems to be a certain symmetry of the members. The end, also, appears to be preferable to those things tending to the end, and of two things, that which is nearer to the end, and in short, what contributes to the end of life, is preferable to what (tends) to something else, as that which contributes to felicity, than what tends to prudence. Moreover, the possible than the impossible, and when there are two efficients, that of which the end is better. The efficient, however, and the end, (we must consider) from analogy when one end more surpasses another, than that, its own efficient cause, thus, if felicity more excels health than health the salubrious, what is productive of felicity will be better than health, for as far as felicity surpasses health, so far what is productive of felicity surpasses the salubrious. Nevertheless, health less surpasses the salubrious, so that what is productive of felicity more surpasses the salubrious then does health the salubrious. Evidently, then, what is productive of felicity is preferable to health, since it more surpasses the same thing.

Once more, the more beautiful per se, and the more honourable and praiseworthy, as friendship than wealth, and justice than strength, for the one are per se amongst things honourable and praiseworthy, but the other not per se, but on some other account, since no one honours wealth for itself, but for something else, but friendship for itself, even if nothing else should result to us from it.

Moreover, when two things are very like each other, and we cannot perceive any superiority of the one to the other, we must investigate from the consequents, for whichever the greater good follows, is the preferable. Still, if the consequents be evil, that which the less evil follows is preferable, for both being eligible, there is nothing to prevent something troublesome resulting. The investigation indeed from the consequent is two-fold, since it follows both prior and posterior, as to the learner ignorance is prior, but knowledge posterior; for the most part however the latter consequent is better, so that we must take whichever consequent may be useful.

Again, many goods (are to be preferred) to fewer, either simply, or when some are inherent in others, viz. the fewer in the more: it is objected if anywhere one thing is for the sake of another, for both are not at all preferable to the one; thus, to be made well and health are not preferable to health, as we choose to be made well on account of health, still there is nothing to prevent things which are not good, conjoined with such as are good, from being more eligible, as felicity and something else, which is not good, than justice and fortitude, and the same things with pleasure, rather than without pleasure, and the same things with painlessness than with pain.

Besides, each thing at the time of its greatest power is more eligible, as to be without pain in old age rather than in youth, for it is capable of effecting more in old age. So also prudence in old age is preferable, because no one chooses the young as leaders from not deeming them prudent. Courage indeed is contrary, for courageous energy is more necessary in youth; so also temperance, for the young are more burdened by desires than elderly men.

Whatever also is useful at every time or at most times, is more useful, thus justice and temperance than courage, for the former are always, but the latter is sometimes useful. Again, that which all men possessing we require nothing else, (is more eligible) than that which (all) possessing we should require something else beside, as in the case of justice and courage, for if all men were just, courage would not at all be useful, but though all men were courageous, justice would be useful.

Further, (we can derive arguments) from corruptions and rejections, generations, assumptions, and contraries, for those, the corruptions of which are more to be avoided, are themselves more eligible. Likewise with rejections and contraries, for whether the rejection or the contrary is more to be avoided, it is itself more eligible. Still in generations and assumptions the contrary occurs, and those are more eligible whose assumptions and generations are so.

Another place is, that the nearer to the good is better and preferable, also the more similar to the good, as justice than a just man. Likewise what is more similar to the better than itself, as some say that Ajax was better than Ulysses, because he was more similar to Achilles. The objection to this is that it is not true, since nothing prevents Ajax from being more similar to Achilles, not so far as Achilles was the best; the other (Ulysses) being indeed good, yet not similar. We must also see whether the similar exists in things more ridiculous, as an ape is like a man, when a horse is not so, since the ape is not more beautiful, but more similar to man. Again, in two things, if one more resembles the better, but the other the worse, that will be the better which more resembles the better. Yet this also has an objection, since there is nothing to prevent the one being in a small degree similar to the better, but the other being very similar to the worse. As if Ajax was a little like Achilles, but Ulysses excessively like Nestor. Also if what resembles the better is like so far as pertains to the worse, but what resembles the worse so far as belongs to the better, as a horse with respect to an ass, and an ape to a man.

Another, the more illustrious, (is preferable) to that which is less so, likewise the more difficult, for the possession of those things is dearer to us which cannot easily be obtained. Again, the more peculiar than the more common. Also that which has less connexion with evils, for that is preferable which no molestation follows, rather than that which it does follow.

Again, if this is simply better than that, that which is the best in this, is better than that which is the best in the other, as, if man is better than horse, the best man also is better than the best horse, and if the best is better than the best, this also is simply better than that, thus, if the best man is better than the best horse, man also simply is better than horse.

Further, those things of which our friends can share are preferable to what they cannot partake of: also those which we would rather do for a friend, are preferable to what we would do for any one, as, to act justly and to do good are preferable to seeming (to do so), for we rather desire to benefit our friends than to seem (to benefit them), but contrarily with regard to casual persons.

Also those which are from abundance are better than such as are necessary, and sometimes indeed are more eligible, for to live well, is better than to live merely, but to live well is from the abundant, and to live itself, is necessary. Sometimes however things which are better are not also more eligible, for if they are better, it is not necessary that they should be more eligible, for instance, to philosophize is better than to get money, yet it is not more eligible to one in want of necessaries. Still it is from abundance, when necessaries being (supplied), a person procures certain other things good; yet perhaps the necessary is almost preferable, but that from abundance is better.

Again, that which cannot be supplied by another is better than what another may supply, as justice fares with regard to courage, also if this thing is eligible without that, but not that without this, as power is not eligible without prudence, but prudence is eligible without power. Also if we deny one of two, that the other may seem to be present with us, that is the more eligible which we desire to seem present, as we disclaim labour in order to appear talented.

Again, that, the absence of which we reprove persons less for bearing with difficulty, is more eligible, and that, the absence of which when it is not borne with difficulty, we rather reprove, is also more eligible.

Moreover of things under the same species, that which possesses its own proper virtue (is preferable) to what does not, but when both possess it, that which has it in a greater degree. Further, if one thing causes that to be good with which it is present, but another does not, the efficient is preferable, as what heats is hotter than what does not, yet if both cause it, that which causes it the more, or that which renders the better and more principal thing good, as if one thing causes the soul, but another the body.

Again, from cases, uses, actions, and works, and these from those, for they follow each other; for example, if justly is preferable to courageously, justice also is preferable to courage, and if justice is preferable to courage, justly also is preferable to courageously, and similarly in other things.

Besides, if of the same thing one is the greater good, but the other the less, the greater is preferable, or if it is the good of the greater, it is the greater (good). But also if two things are preferable to a certain thing, the more eligible is to be preferred to the less eligible. Again, that of which the excess is more eligible than the excess (of another thing), is itself more eligible, as friendship than wealth, for the excess of friendship is preferable to the excess of wealth. Also that which a man would rather procure through himself, than which (he procures) through another, e.g. friends than money.

Again, also from addition, if any thing being added to the same, renders the whole more eligible: we must be careful, however, lest we propose such things, in which what is common is employed in one of the things added, or is in some other way co-operative with it, but the rest is not used nor is co-operative; for example, a saw and a sickle (being joined) by constructive art, the saw when conjoined is more eligible, but simply is not so. Again, if any thing being added to the less renders the whole greater. Likewise also from detraction, for when any thing being taken away from the same, the remainder is less, that (which was taken away) will be greater, since what is removed renders the remainder less.

Also, if one is eligible for itself, but the other on account of estimation, as health than beauty. Now, the definition of what is eligible on the score of estimation, is that if no one were conscious, we should not endeavour to obtain it. And it one thing is eligible for its own sake, and on account of estimation, but the other on account of one of them only. And that which is more honourable for its own sake is better and more eligible, but that would be more honourable per se, which, nothing else being about to result, we rather prefer for its own sake.

Moreover, we must distinguish in how many ways the eligible is predicated, and for the sake of what things, as for that of the profitable, or the beautiful, or the pleasant, for whatever is useful to all or to the greater number, would be more eligible than that which is not similarly (so useful). When, however, the same are present to both, we must consider with which they are more present, whether it be the more pleasant, or the more beautiful, or the more profitable. Again, what is for the sake of the better, is more eligible, as what is for the sake of virtue than what is for the sake of pleasure. It is the same also in things to be avoided, for that is more to be avoided which is more an impediment to the eligible, as disease than deformity, since disease is a greater impediment both to pleasure and probity.

Once more, from similarly demonstrating, that the thing proposed is to be avoided and chosen, for a thing of such a kind as that one may similarly choose and avoid it, is less eligible than another thing which is eligible only.

We must make then, as we have said, comparisons of things with each other. The same places, however, are also useful for showing whatever is to be chosen or avoided, for it is only requisite to take away the excellence by which one thing surpasses another. For if the more honourable is more eligible, the honourable also is eligible, and if what is more useful is more eligible, the useful also is eligible, it is the same also in other things which have such a comparison. Still in some, by making a comparison of one with the other, we pronounce directly, that either, or that one of them, is eligible, as when we say, that one thing is naturally, but another not naturally, good, for what is naturally good is evidently eligible.

Places pre-eminently universal are to be assumed of the more and greater, for when they are thus assumed they will be useful for more (problems); still we may render some of those we have mentioned, more universal by changing the appellation in a slight degree; thus, what is such by nature, is more such than what is not such by nature. Also, if the one causes, but the other does not cause, the thing which possesses that to be such, in which it is inherent; what is sometimes the cause, is more a thing of this kind than what is not the cause, but if both are causes, that which is rather the cause is a thing of this kind.

Further, if of the same thing, one is more, but another less such, and if the one of a thing of this kind is more such, but the other is not of such a thing such, it is evident that the first is more a thing of this kind. Moreover, from addition (we may derive) a topic, if something being added to the same, renders the whole more such, or if what is added to the less such, makes the whole more such. Likewise from detraction, for that which being taken away, the remainder is less such, is itself more such. Also things which are more unmixed with contraries are more such, as that is whiter which is more unmixed with black. Besides, what has been said before, there is that which is more recipient of the proper definition of the thing proposed, as, if the definition of whiteness be colour separating the sight, that is more white which is more colour separating the sight.

If the problem should be laid down partially and not universally, all the above-mentioned universal places confirmatory or subversive are useful. For when we subvert or confirm universally, we also demonstrate particularly, since if a thing is present with every, it is also present with a certain one, and if with none, neither is it with any one. Notwithstanding, those places are above all opportune and common, which are assumed from opposites, coordinates, and cases, for it is similarly probable to assume, if every pleasure is good, that all pain likewise is an evil, and if a certain pleasure is good, that a certain pain also is an evil. Yet more, if a certain sense is not a power, a certain privation of sense also is not impotence, and if a certain thing being the subject of opinion is also that of science, a certain opinion also is science. Again, if any thing unjust is good, something just also is evil, and if any thing done justly is an evil, something done unjustly is good. Also, if something pleasant is to be avoided, a certain pleasure is to be avoided; on this account too, if any thing pleasant is profitable, a certain pleasure is profitable. In things corruptive also, and in generations and corruptions in like manner, for if any thing which is corruptive of pleasure or science is good, a certain pleasure or science would be of the number of things evil; similarly also if a certain corruption of science be among the number of good things, or a generation be among evil things, a certain science will be amongst things evil, for instance, if to forget the base acts a person has committed, is among things good, or to remember them, is amongst things evil, to know the base acts which any one has perpetrated, will be amongst evils. It is the same also with the others, for in all there is similar probability.

Moreover, (there is a place) from the more, and the less, and the similarly. For if any one thing of those from another genus is more such, but no one of those is such, neither will what was mentioned be such, e.g. if a certain science is more a good than pleasure, but no science is good, neither will pleasure be. And in the same way from the similarly and the less, for both to subvert and to confirm, will be possible, except (that we may do) both from the similarly, but from the less, only confirm, and not subvert. For if a certain power is similarly good, and science, but a certain power is good, a certain science also is, but if no power, neither is science; still, if a certain power is less a good than science, but a certain power is good, science also is. On the other hand, if no power is good, it is not necessary also that no science should be good, wherefore we can evidently only confirm, from the less.

Notwithstanding, we may not only subvert from another genus, but also from the same, by assuming what is especially such; as if it is admitted that a certain science is good, but it should be shown that prudence is not good, neither will any other be, since what especially seems (good) is not (so). Once more, from hypothesis, when in the same way it is assumed, that if a thing is present or not, with one, it is also or not, with all, as if the soul of man is immortal, that other (souls) also are, but if this is not, that neither are the others. If indeed then a thing is assumed present with a certain one, it must be proved not present with a certain one, since it will follow through the hypothesis that it is present with nothing, but if it is laid down not present with any, we must show that it is present with some one, for thus it will follow that it is present with all. Indeed it is evident that he who makes this hypothesis , makes the problem universal, which was laid down as particular, for he requires that to be acknowledged universal, which was allowed to be particular, since if it is present with one, he assumes it similarly present with all.

The problem then being indefinite, it is possible to subvert it in one way, as if a person said that pleasure is good or not good, and added nothing else in the definition. For if he said that a certain pleasure is good, we must show universally that no pleasure is, if the proposition is to be subverted. In like manner, also, if he said that a certain pleasure is not good, we must show universally that all is, for otherwise subversion is impossible; since if we have shown that a certain pleasure is not good, or that it is good, the proposition is not yet subverted. It is evident then, that subversion is possible in one way, but confirmation in two, for both whether we show universally that all pleasure is good, or that a certain pleasure is good, the proposition will have been proved. Likewise if it should be required to be argued that a certain pleasure is not good, if we have proved that no pleasure is good, or that a certain one is not good, we shall have argued in both ways, both universally and particularly, that a certain pleasure is not good. The thesis indeed being defined, it will be possible to subvert in two ways, as if it should be laid down that good is present with a certain pleasure, but with a certain (pleasure) is not present, since whether all pleasure, or no pleasure, be proved good, the proposition will be subverted. Still, if it has been admitted that one pleasure only is good, subversion is possible in three ways, for by showing that all, or that none, or that more (pleasures) than one, are good, we shall have subverted the proposition. Nevertheless, the thesis having been defined to a greater extent, as that prudence alone of the virtues is a science, subversion is possible in four ways, for it having been shown that every virtue is science, or that none, or that some other (is a science), as justice, or that prudence itself is not a science, the proposition will have been subverted.

It is also useful to attend to singulars, in which something was said to be inherent or not, as in universal problems. Again, we must look to genera dividing according to species, as far as to individuals, as we observed before, for whether a thing appears present with every, or with none, (the opponent) must be required by him, who has adduced many things, to acknowledge universally, or to bring an objection, in what thing it is not so. Besides, in what things it is possible to define accident, whether in species or in number, it must be considered, if no one of these is present, as that time is not moved, and that neither is it motion, having enumerated how many species of motion there are, since if not one of these is present with time, it is evidently not moved, neither is it motion. Likewise also, (if we wish to show) that the soul is not number, (we must prove) by division, every number is either odd or even, as, if the soul is neither odd nor even, it is clearly not number.

For accident then we must argue through such (places) as these, and in such a manner.

Our attention must now be directed to what appertains to genus, and property, and these are the elements of such as belong to definitions, but about them there is seldom a consideration by disputants. If then it should be laid down that there is a genus of any certain thing, we must first have respect to all things allied to what is spoken, whether it is not predicated of something, as is the case with accident, as if good is assumed as the genus of pleasure, (we must see) whether a certain pleasure is not good; for if this happens, it is clear that good is not the genus of pleasure, since genus is predicated of all things under the same species. Next, whether it is not predicated in answer to the question, what a thing is; but as accident, as whiteness, of snow, or what is moved by itself, of the soul; for neither is snow, the same thing as whiteness, wherefore whiteness, is not the genus of snow, nor is the soul, the same as what is moved, but it is accidental to it, to be moved, as also it frequently happens to an animal, to walk and to be walking. Moreover, the being moved, is not a certain thing, but appears to signify something active, or passive; likewise also whiteness, for it does not discover what snow is, but what kind of thing it is; hence neither of these, is predicated in reply to the question what a thing is.

Notwithstanding, we must especially have regard to the definition of accident, if it concurs with the stated genus, as also in what has just now been mentioned, for the same thing may possibly move, and not move itself, likewise also may be white, and not white, so that neither of these is genus, but accident, since we denominate that accident, which possibly may, and may not be present, with a certain thing.

Further, whether the genus and the species, be not in the same division, but the one, essence, and the other, quality, or the one, relative, but the other, quality, for instance, snow is essence, also a swan, yet whiteness is not essence, but quality, so that whiteness is neither the genus of snow, nor of a swan. Again, science is of the number of relatives, but good, and beautiful, are each a quality, hence neither the good, nor the beautiful, is the genus of science, since the genera of relatives, must necessarily themselves also, be relatives, as in the instance of the double, for the multiple being the genus of the double, is itself of the number of relatives. To speak universally, genus must be under the same division with species, for if the species be essence, the genus also is, and if the species be a quality, the genus also is some quality, as if whiteness is a certain quality, so also is colour, and likewise in other cases.

Further, (we must examine) whether it is necessary or contingent that genus partake of that which was laid down in genus, and the definition of partaking, is to receive the definition of what is participated. Now it is evident that species partake of genera, but not genera of species, since the species accepts the definition of genus, but not genus that of the species. Wherefore we must observe, whether the proposed genus partakes, or can partake, of species, as if some one should declare that there is a certain genus of "being," or of "the one," for the genus will happen to partake of the species, since "being" and "the one" are predicated of all entities, so that their definition is (predicated) also.

Besides, whether the assigned species is truly predicated of a certain thing, but not the genus, as if "being" or the object of science is laid down as the genus of what is the object of opinion, for the object of opinion will be predicated of non-entity, since many non-entities are the objects of opinion. Still that being, or the object of science, is not predicated of non-entity, is evident, wherefore neither "being" nor the object of science, is the genus of the object of opinion, as of what species is predicated, genus must also of necessity be predicated.

Again, whether what is placed in the genus can possibly partake of no species, since it is impossible that what partakes of no species, should partake of genus, unless it should be one of those species according to the first division, for these alone partake of genus. If, then, motion be assumed as the genus of pleasure, we must see whether pleasure be not production, nor alteration, nor any one of the other assigned motions, for it is palpable, that it partakes of no species, wherefore neither of the genus, since it is necessary that the participant of the genus, should also be participant of some species, so that pleasure can neither be a species of motion, nor an individual, (neither among those which are under a species of motion). For individuals partake, also, of genus and species, as a certain man, participates both of man, and of animal.

Besides, whether what is placed in genus, is of wider extension than the genus, as the subject of opinion, than entity, since both entity, and non-entity, are objects of opinion, wherefore, the object of opinion, will not be a species of entity, as the genus is always more widely extended than the species. Again, whether the species and the genus are predicated of an equal number of things, as if amongst those which are consequent to all, one should be placed as species, but the other as genus, as "being," and "the one;" for "being," and "the one," (are consequent) to every thing, so that neither is the genus of the other, since they are predicated of an equal number. Likewise also, if the first and the principal, be placed, one upon the other, since the principal is what is first, and what is first is principal, so that either both stated are the same, or neither is the genus of the other. Still the element relative to all such is, that the genus is of wider extension than the species and the difference, for difference, also, is predicated of fewer things than genus.

Also, examine whether what has been mentioned be not, or appear not to be, the genus of some one of those things which do not differ in species, the supporter of the argument, however, (will see) whether it is (the genus) of one of these, for there is the same genus of all things not different in species. If, then, it be shown to be the (genus) of one, it is evidently that of all, and if not of one, evidently not of any, as if some one admitting that there are indivisible lines, should say that their genus is indivisible, for what has been stated is not the genus of lines, admitting division, as they are not specifically different, for all straight lines do not specifically differ from each other.

Consider, also, whether there is any other genus of the assigned species, which neither comprehends the assigned genus, nor is under it, as if some one should assert science to be the genus of justice, since virtue also is genus, and neither of these genera comprehends the other, so that science would not be the genus of justice, for apparently, when one species is under two genera, one is comprehended under the other. This, nevertheless, is doubtful in some cases, for to some, prudence seems both virtue and science, and neither of the genera to be comprehended under the other, yet it is not admitted by all, that prudence is science; if, then, any one admitted the statement to be true, yet it will appear necessary that genera of the same thing, should be either subaltern, or both under the same genus, just as it happens in virtue and science, for both are under the same genus, since each of them is habit and disposition. We must see, therefore, whether neither of them is present with the assigned genus, for if they are neither subaltern genera, nor both under the same genus, what is assigned will not be a genus.

We must observe too the genus of the assigned genus, and so always the superior genus, whether all things are predicated of the species, and whether they are so in reply to what a thing is, for all superior genera must be predicated of species, in respect to what a thing is; if then there is any where a discrepancy, what is assigned, is evidently not the genus. Again, whether the genus partakes of the species, either itself, or any of the superior genera, as the superior (genus) partakes of none of the inferior. The subverter must use what we have said, but for the supporter it will be sufficient (if the proposed genus is admitted present with the species, but it is doubtful whether it is present with genus) to show that some one of the superior genera is predicated of species, in reference to what a thing is. For if one thing is predicated in reference to what a thing is, all, both above and below this, if they are predicated of species, will be so predicated in reference to what a thing is, so that the assigned genus also is predicated in reference to the same. But that if one is predicated in reference to what a thing is, all the rest will be so, if they are predicated, must be assumed from induction: nevertheless, if it is doubted whether the assigned genus is simply inherent, it is not enough to show that any of the superior genera is predicated of species, in respect to what a thing is, e. g. if some one gave lation, as the genus of walking, it is not sufficient to show that walking is motion, in order to prove that it is lation, since there are other motions also, but we must prove besides, that walking partakes of none of those in the same division, except lation. For it is necessary that the participant of genus, should also participate of some one species, according to the first division; if then walking, neither partakes of increase, nor of diminution, nor of the other motions, it clearly partakes of lation, so that lation would be the genus of walking.

Again, in those where the assigned species is predicated as genus, observe whether the assigned genus also is predicated of the same things of which species is, in reference to what a thing is, likewise whether all those things which are above the genus. For if there is any discrepancy, what is assigned is evidently not genus, as if it were genus, all things above this, and the very thing itself, would be predicated in reference to what a thing is, of which things species also is predicated, in respect of the same. Now this is useful to the subverter, if the genus is not predicated in respect to what a thing is, of which thing, species also is predicated, but to the confirmer it is useful, if it is predicated in the question, what a thing is. For both the genus and the species, will happen to be predicated of the same, in respect to what a thing is, so that the same thing is under two genera, wherefore the genera are necessarily subaltern. If then what we wish to constitute genus is shown not to be under species, species will be evidently under it, so that it will have been proved that this is genus.

Examine moreover, the definitions of the genera, whether they suit the assigned species, and the participants of the species, since it is necessary that the definitions of the genera, should be predicated of the species, and of what partakes of the species, so that if there is any where a discrepancy, it is manifest that genus is not, what has been assigned.

Again, whether a person has given the difference, as a genus, must be (looked to); for instance, whether the immortal, as a genus of God, for immortal, is the difference of animal, since of animals, some are mortal, but some immortal, so that there is evidently an error, for the difference, is not the genus, of any thing. But that this is true is evident, for no difference signifies what a thing is, but rather of what quality it is, as pedestrian, and biped.

Also whether difference is placed in genus, as that the odd is that which is number, since the odd is a difference, not a species, of number. Neither does difference seem to partake of genus, for every thing which partakes of the genus, is either species or individual; but difference is neither species nor individual, wherefore clearly difference, does not partake of genus, so that neither would the odd, be species, but difference, since it does not partake of genus.

Moreover, whether genus is placed in the species, for instance, that conjunction is continuity, or that mixture is temperament, or as Plato defines, that local motion is lation, since it is not necessary that conjunction should be continuity, but on the contrary that continuity should be conjunction, since not every thing which touches is continuous, but every thing which is continuous touches. The like also occurs with the rest, for neither is all mixture, temperament, (as the mixture of dry things, is not temperament,) neither is all local change, lation, since walking, does not seem to be lation. For (the latter) is asserted generally of those, which involuntarily change their place, as happens to inanimate natures. Nevertheless, it is evident, that species is more widely predicated than genus, in the cases advanced, when the contrary ought to occur.

Again, whether difference is placed in species, as that the immortal, is that which is God. For species will happen to be predicated, either equally or of more, since difference is always predicated equally with, or to a greater extent than, species. Moreover, whether the genus is placed in the difference, as that colour, is what concretes, or that number, is the odd. Likewise, if the genus has been spoken of, as if it were difference; for it is possible that some one may adduce, even a thesis of this kind, as that mixture is the difference of temperament, or local change, the difference of lation. All such particulars however, we must consider through the same, (for places intercommunicate,) since both the genus must necessarily be predicated more extensively than the difference, and must not partake of difference, but when it (genus) is thus assigned, neither of what have been mentioned can possibly occur; for it will be spoken of fewer things, and genus will partake of difference.

Besides, if no difference of genera is predicated of the assigned species, neither will the genus be predicated, thus neither the odd, nor the even, is predicated of the soul; wherefore neither is number. Moreover, if species is prior naturally, and co-subverts the genus, (it will not be genus,) for the contrary appears to be true. Once more, if is possible (for species), to leave the proposed genus or difference, as to be moved, the soul, or the true and the false, opinion, neither of these named would be genus or difference, for genus and difference are apparently consequent so long as there is species.

Moreover, we should observe whether what is laid down in the genus, partakes or can partake, of something contrary to genus, since the same thing, will, at the same time, partake of contraries, as it (species) never leaves genus, but partakes, or is capable of partaking, of what is contrary. Besides, whether species communicates with any thing which cannot altogether be present with those which are under genus, thus, if the soul partakes of life, but no number can possibly live, the soul would not be a species of number.

Notice also, whether the species is equivocal with the genus, employing for (the investigation of) the equivocal, the elements before mentioned, for genus and species, are synonymous.

Since however there are many species of every genus, we must observe whether there may not be another species of the proposed genus, for if there is not, it is evident, in short, that the thing spoken of will not be genus.

Likewise observe, whether a person has proposed as genus, that which is spoken of metaphorically, as that temperance is symphony, for every genus is properly predicated of species, but symphony is not properly predicated of temperance, but metaphorically, for all symphony is in sounds.

Again, whether a thing be contrary to species; and this consideration is multifarious; first, indeed, whether in the same genus there is also a contrary when there is not a contrary to genus, for contraries must necessarily be in the same genus, if nothing is contrary to genus. If however there is any thing contrary to genus, we must observe whether the contrary is in the contrary (genus), since it is necessary that the contrary should be in the contrary, if any thing is contrary to genus; each of these however appears through induction. Moreover, if in short the contrary to species, is in no genus, but is itself a genus, as the good, for if this is not in genus, neither will the contrary to this be in genus, but will be itself genus, as happens in the case of good and evil, since neither of these is in genus, but is each of them a genus. Further, whether both genus and species are contrary to a certain thing, and whether there is any thing between some, but not between others. For if there is something between genera, there is also between species, and if between species, likewise between genera, as in virtue and vice, and justice and injustice, for there is something between each of these. To this it may be objected, that there is nothing between health and disease, but that there is something between evil and good, or whether there is something between both the species and genera, yet not similarly, but between the one negatively, and between the other as a subject, for it is probable that something similarly intervenes between both, as between virtue and vice, justice and injustice, for there are intermediates between both, according to negation. Further, when there is not a contrary to genus, we must observe not only whether the contrary is in the same genus, but also whether the medium is, for the media are in the same genus as the extremes, as, for instance, in white and black, for colour is both the genus of these, and of all intermediate colours. An objection may lie, that defect and excess, are in the same genus, (as both are in what is evil,) but the moderate, which is a medium between these, is not in what is evil, but in what is good. Notice too, whether the genus is contrary to a certain thing, but the species to nothing, as if the genus is contrary to a certain thing, the species is also, as virtue and vice, justice and injustice. Likewise, to one who considers other things, such a thing would appear evident. There is an objection in health and disease, for health simply, is contrary to disease, yet a certain disease, being a species of disease, is not contrary to any thing, e. g. a fever and ophthalmia, and every other (disease).

The subverter then, must pay attention in so many respects, for if what have been mentioned are not inherent, the thing assigned is evidently not a genus, but the confirmer (must regard them) triply: first, whether the contrary to species is in the before-named genus, when there is not a contrary to the genus, for if the contrary is in this, it is evident that the proposition is also: next, whether the medium is in the above-named genus, as in what the media are the extremes also are: lastly, if there be any thing contrary to genus we must notice whether the contrary also is in the contrary, since if it be, the proposed (species) is evidently in the proposed genus.

Again, in cases and co-ordinates, both the subverter and confirmer (must notice) whether they are similarly consequent, since at the same time they are present, or are not present, with one thing, and with all, as if justice is a certain science, what is justly, is also scientifically, (done), and a just is a scientific man, but if something of these is not, neither is any of the rest.

Such things also (must be noticed), which are similarly affected with respect to each other, thus the pleasant subsists with reference to pleasure, similarly to the useful with reference to good, for each is effective of the other. If then pleasure is what is good, the pleasant will be what is useful, for it would be clearly effective of good, since pleasure is good. The like also occurs in generations and corruptions, as, if to build is to energize, to have built is to have energized, and if to learn is to remember, to have learned is to have remembered, and if to be dissolved is to be corrupted, to have been dissolved is to have been corrupted, and dissolution is a certain corruption. So also in those which have the power to generate and to corrupt, and in powers and uses, and in short, according to any kind of likeness, as we have observed in generation and corruption, consideration must be paid both by the subverter and the confirmer. For if what is corruptive dissolves, to be corrupted is to be dissolved, and if what is generative is effective, to be generated is to be made, and generation is making, and the same in powers and uses, since if power is disposition, to be able also is to be disposed; and if the use of a thing is energy, to use is to energize, and to have used is to have energized.

If however privation be that which is opposed to species, we may confute in two ways: first, if the opposed be in the assigned genus, for either privation simply, is in no genus, which is the same, or it is not in the (same) extreme genus, as if sight is in sense, as the extreme genus, blindness will not be sense. Secondly, if privation is opposed both to genus and to species, but the thing opposed is not in the opposite, neither will the thing assigned be in the assigned; by him therefore who subverts, this must be used as we have said, but by the constructor only in one way, for if the opposite be in the opposite, the proposition also would be in the proposition, thus, if blindness be a certain privation of sense, sight also is sense.

Again, we must consider negatives inversely, as was observed in the case of accident, thus, if the pleasant be what is good, what is not good is not pleasant, for if it were not so, something not good would be pleasant. Now it is impossible, if good is the genus of the pleasant, that any thing not good should be pleasant, for of what genus is not predicated, neither will any species be. He also who confirms, must consider it in like manner, since if what is not good is not pleasant, the pleasant is good, so that the good is the genus of the pleasant.

If however species be relative, we must see whether genus also is relative, for if species be a relative, genus is also, as in the double and the multiple, for each of these is a relative. If then genus be a relative, it is not requisite that species also should be, for science is of the number of relatives, but grammar is not. Or does what was before asserted appear neither to be true? for virtue is that which is beautiful and which is good, and virtue is a relative, but the good and the beautiful are not relatives, but qualities.

Moreover, (notice) whether species is not referred to the same thing, both per se, and according to genus, as if the double is said to be the double of the half, it is necessary also that the multiple should be said (to be the multiple) of the half, for if not the multiple will not be the genus of the double.

Besides, whether it is not referred to the same thing, both according to genus and according to all the genera of the genus, for if the double and the multiple are with reference to the half, to exceed will also be predicated of the half, and in short, according to all the superior genera there will be a reference to the half. It is objected, that a reference to the same thing is not necessary per se, and according to genus, for science is said to be of that which is the object of science, but habit and disposition are not predicated with reference to the object of science, but to the soul.

Again, whether genus and species are predicated in the same manner as to case, as whether pertaining to a certain thing, or predicated of something, or in some other way, for as species, so also is genus (predicated), as in the double, and the superior (genera), for both the double and the multiple are predicated of a certain thing. Likewise in the case of science, for both science itself and its genera, as disposition and habit, are (predicated) of a certain thing. It is objected, that sometimes this is not the case, for "the different," and "the contrary," (are predicated) with reference to a certain thing, but "another" being the genus of these, is not predicated with reference to, but from, something, for (a thing) is so predicated "another," (which is different) from, something else.

Moreover, whether what are similarly called relatives, according to cases, do not similarly reciprocate, as with the double and the multiple, for each of these is said to be of something, both itself, and reciprocally, for both the half and the least part, (are said to be so) of something. Likewise with science and opinion, for these are said to be of a certain thing and similarly reciprocate, and both the object of science and of opinion are predicated with reference to something. If, then, the reciprocation is not similar in the respect of something, one is evidently not the genus of the other.

Again, if genus and species are not predicated with reference to an equal number of things, for each, seems predicated similarly, and of the same number, as in "a gift," and "giving," for a "gift," is said to be "of" some one, or "to" some one, and "giving" also, "of" a certain one, and "to" a certain one; still "giving" is the genus of "gift," for "a gift," is "a giving" not to be returned. With some, predication with reference to an equal number, does not occur; for the double is the double of something, but the excessive, and the greater, (are predicated) of, and with reference to, a certain thing, for every thing excessive, and that which is greater, exceeds in something, and is the excess of a certain thing. Wherefore, what are mentioned, are not the genera of the double, since they are not predicated with reference to an equal number in species, or it is not universally true that species and genus are predicated with reference to an equal number of things.

Examine, likewise, whether the opposite is the genus of the opposite, as if the multiple is the genus of the double, the sub-multiple is so, of the half, for the opposite must necessarily be the genus of the opposite. If, then, any one asserts science to be sense, it will be requisite that the object of science should be sensible, which, however, is not the case, for not every object of science is sensible, as some things intelligible are objects of science. Wherefore, the sensible is not the genus of the object of science, but if it be not, neither is sense, the genus of science.

Nevertheless, since of those which are enunciated with reference to any thing, some are necessarily in, or about, those, to which they happen to be referred, as disposition, habit, and symmetry, (for these can possibly be in nothing else, than in those things to which they are referred;) but others are not necessarily in those, to which they are sometimes referred, yet may be in them, (as if the soul is an object of science, since nothing prevents the soul having science of itself, yet it is not necessary, since this very science may possibly be in something else;) others, again, cannot simply be inherent in those to which they happen to be referred, (as the contrary can neither be in the contrary, nor science in its object, unless the object of science should be the soul or man;) we must observe, whether any one places a thing of this kind in a genus, which is not of this kind, as if he declared that memory is the permanency of science. For all permanency is in, and about, that which is permanent, so that the permanency of science is in science; memory therefore is in science, since it is the permanency of science, yet this is impossible, for all memory is in the soul. The place here spoken of, is common also to accident, for it does not signify whether we say that permanency is the genus of memory, or call it accidental to it; since if in any way whatever, memory is the permanency of science, the same reasoning will suit it.

Again, if a person has referred habit to energy, or the energy to the habit, as that sense is a motion through the body, for sense is a habit, but motion an energy. Likewise, if he has stated memory to be a habit retentive of opinion, since no memory is a habit, but rather an energy.

They also err, who arrange habit under consequent power, as that mildness is a command of anger, and that courage and justice are the control of fear and lucre, for the impassive man is said to be courageous and mild, but he is self-controlled, who, when he suffers, is not carried away. Perhaps, therefore, such a power as this is consequent to each, so that if he suffers, he should not be transported by, but command (passion). Yet this is not the essence of a courageous or a mild man, but not to be affected at all, by such things.

Sometimes, indeed, they admit as genus, that which is in any way consequent, as that pain is the genus of anger, and opinion of faith, for both these we have named follow in a certain way the assigned species, yet neither of them is a genus, for the angry man is pained, pain having been produced in him before, since the anger is not the cause of the pain, but the pain of the anger, so that anger simply is not pain. On this account, neither is faith opinion, since it is possible to have an opinion of, without believing in, a thing; and this is impossible, if faith is a species of opinion, for it is impossible that a thing should remain the same any longer, if it has been altogether changed from species, as neither can the same animal by possibility be sometimes man, but sometimes not. Still, if any one say, that he who opines, of necessity also believes, opinion and faith will be predicated of an equality, so that neither thus can it be genus, since it is necessary that genus possess a greater extent of predication.

Observe, moreover, whether both are naturally adapted to be in any the same thing, for in what the species is, the genus also is, as in what there is whiteness, there is also colour, and in what grammar is present, science also is. If then, any one should say that shame is fear, or that anger is pain, species and genus will not happen to be in the same thing, since shame is in the reasoning, but fear in the irascible part of the soul; pain also, indeed, is in the appetitive part, (for pleasure also is in this,) but anger in the irascible part, so that what have been assigned are not genera, since they are not naturally adapted to be in the same (subject) with the species. In like manner also, if friendship be in the appetitive, it could not be a certain will, for all will, is in the reasoning part. This place, indeed, is useful for accident, also; for accident, and that to which it is accidental, are in the same thing, so that unless they should appear in the same thing, they are evidently not accidents.

Further, (notice) whether species partakes of what is said to be genus partially, since genus does not appear to be partially participated, as man is not partially an animal, nor grammar partially a science, likewise also, in other things. Observe, therefore, whether genus is partially partaken of in certain things, as if animal has been said to be that which is sensible or visible, for animal is partially sensible and visible; as to the body, sensible and visible, but not as to the soul; so that the visible and the sensible would not be the genus of animal.

Sometimes, indeed, they insensibly transfer the whole to a part, for instance, that animal is animated body; yet the part is by no means predicated of the whole, so that body would not be the genus of animal, since it is a part.

Also, see if any thing to be blamed or avoided is referred to power or to the possible, as that a sophist (is one able to acquire wealth from apparent wisdom), or that a calumniator (is one able to calumniate and make enemies of his friends), or that a thief is one able secretly to steal the property of others. For no one of the above-named is said to be such in consequence of being able to act in this way, for both God and a good man are able to perform base actions, yet they are not such in character, since all debased characters are called so, on account of their deliberate choice. Besides, all power is of the number of eligible things, for the powers of the bad are eligible, wherefore we say, that both God and the good man possess them, for they are able to perform base actions. So that power would not be the genus of any thing blameable, otherwise it would happen that something blameable was eligible, since there will be a certain power blameable.

Also, (notice) whether any thing which is of itself honourable or eligible, is referred to power, or to the possible, or to the effective, for every power and everything possible or efficient is eligible, on account of something else, or whether any one of those things which are in two or in more genera, have been referred to one, since some things cannot be reduced to one genus, as an impostor and a calumniator; as neither is he who deliberately chooses, but is incapable of effecting, nor he who is capable, but does not previously choose, a calumniator or an impostor, but he who has both these; so that we must not place the above-named in one genus, but in both genera.

Yet further, vice versâ, sometimes they assign genus as the difference, and the difference as genus; e.g. that astonishment is the excess of admiration, and that faith is the vehemence of opinion. For neither excess nor vehemence is genus, but difference; since astonishment seems to be excessive admiration, and faith vehement opinion; so that admiration and opinion are genus, but excess and vehemence are difference. Moreover, if any one should assign excess and vehemence as genera, inanimate things would be susceptible of faith and astonishment, for the vehemence and excess of each thing is present with that of which it is the vehemence and excess; if then astonishment is the excess of admiration, astonishment will be present with admiration, so that admiration will be astonished. In a similar manner also, faith will be present to opinion, if it is the vehemence of opinion, so that opinion will believe. Again, it will occur to him who thus assigns (genus), to call vehemence vehement, and excess excessive, for there is a vehement faith, if then faith is vehemence, vehemence would be vehement, likewise also there is an exceeding astonishment, if then astonishment is excess, excess would be exceeding. Nevertheless, neither of these seems right, as neither is science the object of science, nor motion that which is moved.

Sometimes, indeed, an error arises from placing passion in that which suffers, as a genus, which happens to as many as declare immortality to be perpetual life; for immortality appears to be a certain passion or symptom of life, and that what we have stated is true, may become evident, if any one admits that a person from being mortal has become immortal, for no one would say that he takes another life, but that a certain symptom or passion accedes to this life, wherefore life is not the genus of immortality.

Again, (an error occurs) if that of which there is passion, they declare to be the genus of the passion, as that wind is air in motion, for wind is rather the motion of air, since the same air remains both when it is moved and when it is stationary, so that, in short, wind is not air, for else there would be wind when the air is not moved, since the same air remains stationary which was wind. The like will also happen in other such things, if then it is necessary in this to grant that wind is air in motion, yet such a thing is not to be admitted in all cases, of which the proposed genus is not truly predicated, but in those only wherein it is truly predicated. For in some it does not appear truly predicated, as in clay and snow, for they describe snow to be congealed water; but clay, earth, mingled with moisture; yet neither is snow, water; nor clay, earth; so that neither of the assigned can be genus, for genus must of necessity always be truly predicated of species. In a similar manner neither is wine putrified water, as Empedocles calls it :"—the water putrified in wood." for simply it (wine) is not water.

Further, (we must notice) whether, in short, what is proposed is the genus of nothing, for (if so) it will evidently not be that of the thing enunciated; but this must be considered from those which are participant of the assigned genus, not at all differing in species, as, for instance, white things, for such do not at all differ in species from each other; yet of every genus the species are different, so that whiteness will not be the genus of any thing.

Again, whether that which is consequent to all, has been declared genus or difference, for many things are consequent to all, as "being," and "the one," are of the number of things consequent to all. If then a person has assigned being as genus, it will evidently be the genus of all things, since it is predicated of them, for genus is predicated of nothing else than of species, so that "the one" will be a species of "being." Of all then of which genus is predicated, it happens that species is also predicated, since "being," and "the one," are simply predicated of all, when it is necessary that species should be predicated to a less extent. If however he has stated that what is consequent to all, is difference, it is manifest that difference will be predicated to an equal or greater extent than genus, for if genus is of the number of things consequent to all, it will be predicated to an equal extent, but if genus does not follow all, difference will be predicated to a greater extent than it.

Yet more, (we must observe) whether the assigned genus is stated to be in subject species, as whiteness in snow, so that it will evidently not be genus, for genus is predicated alone of the subject species.

Notice, moreover, whether genus and species are not synonymous, as genus is synonymously predicated of all the species.

Besides, (it is erroneous) when there being a contrary both to species and to genus, the better of the contraries is referred to the worse genus, for the remainder will happen to be in the remainder, since contraries are in contrary genera, so that the better will be in the worse, and the worse in the better, yet the genus of the better, seems also to be better. Also, if when the same species subsists similarly, with regard to both, it is referred to the worse, and not to the better genus, e. g. that the soul is motion or what is moved. For the same (soul) appears equally to possess the power of resting and moving, so that if permanency be better, it ought to be referred to this genus.

Again, the subverter (may argue) from the more and less, if genus accepts the more, but species does not, neither itself, nor what is enunciated according to it. For instance, if virtue accepts the more, justice also, and the just man (do so), for one is said to be more just than another, if then the assigned genus accepts the more, but the species does not, neither itself, nor what is enunciated according to it, the thing assigned cannot be genus.

Again, if what seems to be the more or similarly, is not genus, it is evident that neither is the thing assigned. This place however is useful, especially in such things wherein those appear many, which are predicated of species, in reference to the question what a thing is, and when there has not been definition, neither can we say what is their genus; as of anger, both pain, and the opinion of contempt, seem to be predicated, in reference to what a thing is, since the angry man is pained, and thinks that he is contemned. Indeed there is the same consideration in species, to any one comparing it with something else, as if the more, or what appears similarly to be in the assigned genus, is not in the genus, the assigned species, it is evident, cannot be in the genus.

The subverter then must employ this as we have said, but to the supporter this place is not useful, if the assigned genus and species accept the more, for there is nothing to prevent, when both accept it, one from becoming the genus of the other; for both the beautiful and the white accept the more, and neither is the genus of the other. Yet the comparison of the genera and of the species with each other is useful, as if this, and that, are similarly genus, if one of them is genus, the other also is. Likewise, if the less, the more also is, as if power more than virtue is the genus of continence, but virtue is a genus, so likewise power. The same things will be adapted to be said also of species, for if this, and that, are similarly species of the proposed (genus), if one be species, the other also is, and if the less seeming is species, the more is likewise.

Moreover, in order to confirm, we must examine whether the genus in those things in which it is assigned, is predicated in reference to what a thing is, when the assigned species is not one, but there are many and different (species), for it will be evidently genus. But if the assigned species be one, see whether the genus is predicated also of other species in reference to what a thing is; since, again, it will occur that the same thing is predicated of those which are many and different.

Nevertheless, since difference also appears to some to be predicated of species, in reference to what a thing is, we must separate genus from difference, by employing the above-mentioned elements: first, indeed, because genus is of wider predication than difference; next, because genus is more suitable than difference to enunciate, in answer to the question what a thing is; for he who says that man is an animal, developes in a greater degree what man is, than he who terms him pedestrian—and because the difference always signifies the quality of the genus, but the genus not that of the difference; for whoever terms man pedestrian, describes what kind of animal he is; but he who calls him animal, does not describe of what quality is the pedestrian.

Thus then, we must separate the difference from the genus; since however what is musical, so far as it is musical, appears to be scientific, and music to be a certain science, and if what walks is moved by walking, walking to be a certain motion, we must consider in what genus we desire to construct any thing after the manner stated, e. g. if (we wish to show) that science is faith, (we must notice) whether he who is scientifically cognizant, so far as he is so, believes; for it will be evident that science is a certain faith, and the same method (must be used) in other such cases.

Once more, since it is difficult to separate what is always consequent to a certain thing, and does not reciprocate, (so as to show) that it is not genus, if this is consequent to every individual of that, but that not to every individual of this—as quiet to tranquillity, and divisibility to number, but not the contrary, (as not every thing divisible is number, neither (all) quiet, tranquillity,)—(the disputant) must employ this place, as if genus were that which is always consequent, when the other does not reciprocate; but if another proposes (this argument), it must not be admitted in all cases. The objection to it is, that non-entity is consequent to every thing generated, (for what is being generated, is not,) and does not reciprocate, (for not every non-entity is generated,) yet, nevertheless, non-entity is not the genus of what is being generated, for simply non-entity has no species. About genus then, we must carry on the discussion, as we have stated.

Whether what is asserted be property or not property, must be examined through these (places).

Property is assigned either per se and always, or with relation to something else and sometimes, as the property of man per se is an animal naturally mild, but in relation to something else, as of the soul to the body, that the one commands, but the other obeys; always, as of God to be an immortal animal, but sometimes, as of a certain person to walk in the Gymnasium.

Nevertheless, the property assigned with reference to something else produces either two or four problems. For if it is affirmed of one thing, but the same denied of another, two problems only arise, as of man with regard to horse, the property is that he is a biped. For that man is not a biped may be argued by some one, also that a horse is a biped, and in both ways the property may be removed. But if each is affirmed of each, and denied of each, there will be four problems, as the property of man with reference to horse is that the former is biped, but the latter quadruped, for that man is not a biped and that he is naturally a quadruped may be argued, and that a horse is a biped and not a quadruped is capable of argument, in whatever way therefore it is shown, the proposition is subverted.

That indeed is property per se, which is attributed to all, and separates from every thing, as of man to be a mortal animal capable of science. Property on the other hand with relation to another, is that which does not separate from every thing, but from a certain definite thing, as of virtue in regard to science, the property is that the one is naturally adapted to be in many, but the other in the reasoning faculty alone, and in those who possess the reasoning faculty. Again, the property "always" is that which is true at all times and never fails, as of animal to be composed of soul and body, but the property "sometimes" is that which is true at a certain time, yet does not always follow from necessity, as of a certain man to walk in the Forum.

We may however assign property with reference to something else, when we assert that difference is either in all and always, or for the most part, and in most, for instance, in all and always, as the property of man with respect to horse is the being biped, for both always and every man is a biped, but no horse is ever a biped. For the most part and in most, as the property of the rational in regard to the appetitive and irascible part, is that the one commands, but the other obeys, since neither does the rational always govern, but sometimes is also governed, nor are the appetitive and irascible always governed, but sometimes also govern when a man's soul is depraved.

Of properties however those are especially logical, which are per se, and always, with reference to something else. For the property with reference to something else produces many problems, as also we observed before, since either two or four problems arise from necessity, wherefore many arguments originate in reference to these. Still we may argue about what is per se and always, in reference to many things, or observe it with regard to many times, what is per se indeed, with reference to many things, for it is necessary that property should be present with a subject in regard to each thing that exists, so that if it is not separated as to all, it would not be well assigned as property. But we may observe that which is always, with regard to many times, and both whether it is not present, or was not present, or will not be present, it will not be property. But the property at a certain time, we observe as to the present time, wherefore there are not many arguments belonging to it, but that is a logical problem, in reference to which numerous and good arguments may be framed.

What therefore is stated to be property with reference to something else, must be considered from the places concerning accident, viz. whether it happens to one, but not to another, but those which are at all times, and per se, we must examine by the following places.

First, (it must be considered) whether property be not well or be well explained; of the ill or well, one point indeed is, if the property is laid down, not through things which are more known, or which are more known; subverting it, if not through things more known, but confirming it if through things more known. Now of the (being laid down), not through things more known, one (place) is, if the property which a person assigns, is altogether more unknown, than that of which he states it to be the property, for the property will not be well laid down. For we introduce property for the sake of knowledge, wherefore it should be assigned through things more known, for thus it will be more possible sufficiently to apprehend it. For instance, since he who lays it down as the property of fire to be most similar to the soul, employs the soul, which is more unknown than fire, (for we know more what fire, than what the soul, is,) it would not be well laid down as the property of fire to be most similar to the soul. Another (way) is, if it is not more known that this is present with that, since it is necessary not only that (the property) should be more known than the thing, but also that it should be more known to be present with this thing, since he who is ignorant, whether it is present with this thing, will not know whether it is present with this alone, so that whatever of these happens to be the case, the property becomes obscure. For instance, since he who lays down the property of fire, to be that, in which first, soul is naturally adapted to be, uses what is more unknown than fire, if soul is inherent in this, and if it is inherent in this first, hence that in which first, soul is naturally adapted to be, would not be well placed as the property of fire. We confirm property indeed, if it is placed through things more known, and if through things more known according to each mode, for according to this, property will be well placed, since of the topics capable of confirming any thing well, some will show that it is placed according to this only, but others simply that it is well placed. For instance, since he who says that the property of animal is to possess sense, assigns the property through things more known, and in a manner more known, according to each mode, after this it would be well assigned, as the property of animal to possess sense.

In the next place, we subvert it, (property,) if some one of the names which are assigned in the property is multifariously predicated, or if altogether the sentence also signifies many things, for the property will not be laid down. For instance, since to perceive signifies many things, one to possess sense, but another to use sense, a natural aptitude to sensation would not be well laid down as the property of animal. On this account we must neither employ a name of multifarious signification nor a sentence, as signifying property, because what is multifariously predicated, renders the statement obscure; he who is about to argue being in doubt which of the things multifariously predicated he (the other) means, for property is assigned for the sake of learning. Besides, there must of necessity be a certain elenchus against those who thus explain property, when in (a signification in) which what is proposed is false, some one frames a syllogism of what is multifariously predicated. On the other hand, we confirm it, if neither any one of the names, nor the whole sentence signify many things; for in this respect the property will be well laid down, thus since neither body denotes many things, nor that which is most easily moved to an upward place, nor the whole composed of these, according to this, a body which is most easily moved to an upward place would be well assigned as the property of fire.

In the next place, we subvert it if that is multifariously predicated, of which they assign the property, yet it is not defined, of which of them the property is laid down, for the property (thus), will not be well assigned. On account of what reason is not obscure from what has been before said, for the same things must necessarily result, for instance, since to know this thing scientifically, signifies many things, the property of scientifically knowing this thing, would not be well assigned when it is not defined, of which of them, the property is laid down. We confirm it, however, if that of which the property is placed, be not multifariously predicated, but is one and simple, for as to this, the property will be well laid down, for instance, since man is predicated as one thing, it would be well laid down as to this, that the property of man (consisted in his being) an animal naturally mild.

Again, we subvert it, if the same thing has frequently been mentioned in the property, for oftentimes it escapes notice when men do this, as well in properties as in definitions. Now the property of this kind will not be well laid down, for the frequent repetition disturbs the hearer, so that obscurity necessarily arises, and besides this men seem loquacious. Still it will happen that the same thing is frequently repeated in two modes, the one, when we often denominate the same, as if any one assigned the property of fire to be a body the most subtle of all bodies, (for he repeats the word body,) and in the second place, if a man assumes definitions instead of names, as if he should give as the property of earth, that it was an essence which, most of all bodies, naturally tends to a downward place, and should afterwards assume, instead of (the word) bodies, such essences, for body and such an essence are one and the same thing, so that he will repeat the word essence, and neither of the properties would be well placed. We confirm it, indeed, if no one and the same name be frequently used, for as to this the property will be well assigned, e. g. since he who says, the property of man is an animal capable of science, does not frequently employ the same name, in this respect the property of man would be well assigned.

Next, property is subverted, if such a name is assigned in the property as is present with all, for that will be useless which is not separated from some, but what is asserted in properties, we ought to separate, as also in definitions, wherefore, the property will not be well stated. Thus, since he who assigns as the property of science, opinion immutable by reason, being one, uses a certain such thing in property, viz. one which is present with all, the property of science would not be well stated; on the other hand we confirm it, if no common term has been used, but one separating from a certain thing, for in this respect the property would be well stated, thus, since he who says the property of animal is to have a soul, uses no common (term), in this respect it would be well laid down, as the property of animal, that it possesses a soul. Moreover it is subverted, if a person assign many properties of the same thing, not distinguishing that he assigns many, for the property will not be well placed. For as in definitions it is not requisite that any thing more should be added, than the sentence denoting the essence, so neither in properties should any thing be added, besides the sentence which constitutes what is asserted to be the property, since a thing of this kind is useless. Thus, since he who states that the property of fire is to be a body of the greatest subtlety and lightness, assigns many properties, (for it is true) to assert each of fire alone, it would not be well laid down as the property of fire to be a body, most subtle and most light. On the other hand, he confirms property who has not assigned many properties, but one of the same thing, for as to this, the property will be well stated, thus, since he who says that the property of moisture is a body which can be brought to every shape, assigns one property and not many, in this respect property of moisture would be well stated.

In the next place, the subverter (ought to consider) if he (the proposer) has used that, the property of which he assigns, or some of its (subjects), for the property will not be well laid down. For the property is assigned, for the sake of learning; the same thing therefore is similarly unknown with itself, but what is the subject of a certain thing is posterior to it, and therefore is not more known. Hence, through these, greater instruction in any thing does not happen, e.g. since he who states the property of animal, to be a substance, a species of which is man, uses some one of the subjects of this (animal), the property would not be well stated. But the confirmer (must observe) if he uses neither it, nor any of its subjects, for in this respect, property will be well stated; thus, since he who lays down the property of animal, to be composed of soul and body neither uses it, nor any of its subjects, the property of animal, with regard to this, would be well assigned.

In the same manner, also, consideration must be paid as to the other things which do not, or which do render, a thing more known, subverting, indeed, if what is opposite is used, or in short, what is simultaneous in nature, or any thing posterior, for the property will not be well stated. What is opposite is indeed simultaneous in nature, but what is simultaneous in nature and what is posterior, do not render a thing more known. For instance, since he who states the property of good, to be that which is especially opposed to evil, uses the opposite of good, the property of good would not be well assigned. On the other hand, we confirm it if nothing opposite is used, nor, in short, what is simultaneous in nature, nor what is posterior, for as to this, the property will be well assigned; e.g. since he who lays down the property of knowledge, to be a notion in the highest degree credible, uses neither an opposite, nor what is simultaneous in nature, nor what is posterior, so far as regards this, the property of knowledge would be well stated.

We next subvert peculiarity, indeed, if what does not always follow, has been assigned as the property, but that which sometimes happens not to be property, for the property will not be well explained: since neither will the name even be necessarily verified, in respect of that in which we apprehend its being inherent, nor of what it is apprehended not to be inherent, will the name necessarily not he asserted of this. Further, besides these, neither when the property is assigned, will it be clear whether it is inherent, if it is a thing of that kind as to fail, therefore the property will not be clear; e.g. since he who places the property of animal sometimes to be moved and to stand still, has assigned a property which is sometimes not a property, the latter would not be well laid down. On the other hand, it is confirmed, if that is assigned which is necessarily always a property, for in this respect the property would be well stated, since he who asserts the property of virtue to be that which makes its possessor a worthy man, assigns that which always follows as a property, so far as regards this, the property of virtue would be well assigned.

In the next place, it is subverted if some one assigning that which is now a property, does not declare that he assigns what is now a property, since the property will not be well stated. For, first, every thing which is contrary to custom requires explanation, and for the most part, all men are accustomed to assign as property that which is always consequent; secondly, he is uncertain who does not explain whether he desired to state that which is now property, wherefore a pretext of reproof must not be given. For instance, since he who states the property of a certain man, is to sit with a certain man, lays down that which is now a property; he would not place the property well, if he did not speak with explanation. Nevertheless, he confirms it if, assigning what is property at present, he explains that he adduces the present property, for in this respect the property will be well stated; thus, since he who asserts the property of a certain man to be his walking now, asserts this with a distinction, the property would be well alleged.

Next, it is subverted if such a property is assigned, which is in no other way evident to be inherent than by sense, since the property will not be well placed; for every thing sensible, when it is external to sense becomes obscure, since it is not apparent whether it is still inherent, because of its only being known by sense. This, indeed, would be true in those things which do not always follow from necessity. For example, since he who asserts the property of the sun to be the most splendid star moved above the earth, uses such (an expression) in the property, to be moved above the earth, which is known by sense, the property of the sun would not be well assigned, for it would be doubtful when the sun sets, whether it is moved above the earth, because of sense then failing us. Property, however, is confirmed if such a kind has been given, as is not evident to sense, or which, being sensible, is manifestly inherent of necessity, for in this respect the property will be well stated. Thus, since he who lays down, as the property of superficies, to be that which is first coloured, uses, indeed, something sensible, viz. to be coloured, but of such a kind as is evidently always inherent, in this respect the property of superficies would be well assigned.

Next, it is subverted if definition is assigned as property, for the property will not be well stated, since it ought not to manifest the very nature of a thing; e.g. since he who says the property of man is to be an animal pedestrian biped, assigns as the property of man that which signifies his very nature, the property of man would not be well assigned. But we confirm it if a property which reciprocates is assigned, yet which does not manifest the very nature of a thing, since in this respect the property would be well assigned; e.g. since he who states the property of man to be an animal naturally mild, assigns a property which reciprocates indeed, yet does not manifest the very nature of man, in this respect the property of man would be well assigned.

Moreover, it is subverted, if he who assigns the property, does not assert what a thing is, since it is necessary with properties, as with definitions, to assign the first genus, next, to add what remains, and to separate. Hence, the property which is not placed after this manner would not be well assigned; thus, since he who asserts that the property of animal is to have a soul, does not state what an animal is, the property of animal would not be well laid down. Again, we confirm it, if any one, asserting what that is of which he assigns the property, annexes what remains, for in this respect the property will be well assigned; thus, since he who asserts the property of man to be an animal susceptible of science, by asserting what man is, assigns his property, in this respect, the property of man would be well assigned.

Whether, however, what is assigned as property, be so well, or ill, must be examined from such (places), but whether what is stated be altogether property or not property, must be inspected from these. For those which simply confirm that the property is well stated, will be the same places as those which produce property at all, therefore they will be explained with them.

First then in confirmation, we must regard each particular, of which the property has been assigned, as whether it is present with no individual, or is not verified in this respect, or whether it is not the property of each of them, as regards that of which the property has been assigned, for the property will not be that which was laid down as the property. For instance, since it is not truly asserted of a geometrician that he cannot be deceived by argument, (for a geometrician is deceived when there is made a false description,) it would not be the property of a scientific man, not to be deceived by argument. It is confirmed, on the other hand, if it is verified of every thing, and is true as regards this, for that will be property which was stated not to be property; e.g. since an animal capable of science is verified of every man, and so far as he is man, an animal capable of science would be the property of man. This place indeed is for subversion, if a sentence is not verified of what the name is verified, and if of what the sentence is verified the name is not verified, but it belongs to confirmation, if of what the name, the sentence also is verified, and if of what a sentence is predicated, a name also is.

In the next place, we subvert it, if, of what the sentence is, the name also is not verified, and if, of what the name is spoken, the sentence is not, since what is stated to be property, will not be property. For example, since animal partaking of science is verified of God, but man is not predicated, animal partaking of science would not be the property of man. But we confirm it, if, of what the sentence is, the name also is predicated, and if, of what the name, the sentence also is predicated, since that will be property which was stated not to be so; thus, since animal is verified of that of which the possession of a soul is, and the possession of a soul of that of which animal is, the possession of a soul would be the property of animal.

Again, it is subverted, if the subject is assigned as the property of what is stated in the subject, since that will not be property which is stated to be so; e.g. since he who asserts the property of body, consisting of the most subtle parts, is fire, assigns the subject as the property of that which is predicated, fire would not be the property of a body of the most subtle parts. Wherefore the subject will not be the property of that which is in the subject, because the same thing will be the property of many things specifically different, since many things differing in species are present with the same, being predicated of it alone, the property of all which, will be the subject, if a person thus places the property. Again, property is confirmed if that which is in the subject is assigned as the property of the subject , for that will be property which was stated not to be so, if it is predicated of those alone of which it is said to be the property; thus, since he who says that the property of earth, is body specifically the heaviest, assigns the property of the subject which is predicated of that thing alone, and as a property, the property of earth would be rightly stated.

We next subvert it, if the property is assigned according to participation, for that will not be property which was stated to be so, since what is present according to participation, belongs to the very nature of a thing, but this sort would be a certain difference predicated of some one species: thus, since he who says the property of man is a pedestrian biped, assigns the property according to participation, pedestrian biped would not be the property of man. We confirm, on the contrary, if the property is not assigned according to participation, nor manifests the very nature when the thing reciprocates, for that will be property which is stated not to be property; thus, since he who places the property of animal, as naturally to possess sensation, neither assigns property according to participation, nor manifests the very nature, the thing itself reciprocating with it, naturally to possess sensation, would be the property of animal.

Again, we subvert it, if the property cannot be at the same time inherent, but either subsequent or prior to, that of which it is the name, for what is stated to be property, will not be so, either never, or not always: thus, since it is possible for walking through the forum, to be present with some one, both prior and subsequent to its being man, walking through the forum would not be the property of man, either never, or not always. We confirm it however, if it is always present from necessity at the same time, being neither definition nor difference, since that will be property which was stated not to be so; thus, since animal capable of science, and man, always exist necessarily at one and the same time, being neither difference nor definition, animal susceptible of science, would be the property of man.

Moreover, we subvert it, if the same thing is not the property of the same things, so far as they are the same, since that will not be property which is stated to be so; thus, since it is not the property of what is the object of pursuit, to appear good to certain persons, the latter would not be the property of the eligible, for what is the object of pursuit, and the eligible, are the same thing. But it is confirmed, if the same is the property of the same, so far as it is the same, since that will be property which is stated not to be so: thus, since of man, so far as he is man, the possession of a tripartite soul is said to be the property; the possession of this, would also be the property of mortal, so far as mortal. Now this place is likewise useful for accident, since it is necessary that the same things should be or not be present, with the same things, so far as they are the same.

Again, we subvert, if of things the same in species, the property is not always the same in species, since neither will what is stated be the property of the thing proposed; thus, since man and horse are the same in species, but it is not always the property of a horse to stand from himself, neither will it be the property of man to be moved from himself, since to be moved and to stand from self are the same in species, and happen to each of these, so far as he is animal. On the other hand, we confirm it, if of what are the same in species the property is always the same, for that will be property which is stated not to be so; thus, since it is the property of man to be a pedestrian biped, it would also be the property of bird to be a winged biped, since each of these is specifically the same, so far as some are as species under the same genus, being under animal, but others are as differences of the genus, animal. Now this place indeed is false, when one of those mentioned is present with one species alone, but the other with many, as a pedestrian quadruped.

Since however "same" and "different" are multifariously predicated, it is difficult, when they are sophistically assumed, to assign the property of some one thing alone; for what is present with something to which any thing happens, will also be present with the accident assumed together with that, to which it is accidental; thus, what is present with man, will also be with white man, if man is white, and what is with white man, will also be with man. Some one however may find fault with many of these properties, if he makes one subject subsistent per se, but another with accident, as if he stated man to be one thing, but white man another, moreover, making the habit another, and that which is enunciated according to the habit. For what is present with habit will also be present with what is denominated according to habit, and what is present with that denominated according to habit, will also be present with habit. Thus, since he who possesses science is said to be scientifically disposed, the property of science would not be the being immutable in opinion by reason, for the man of science will be unpersuadable by reason. In confirmation however it must be stated, that that to which a thing happens, and the accident taken together with that to which it is accidental, are not different simply, but they are said to be so from their essence being different, since it is not the same thing for man to be man, and for a white man to be a white man. Besides, we must inspect cases, stating that neither will he be scientific, who is (a thing) unpersuadable by reason, but he who is unpersuadable by reason, nor is science that which cannot be induced to change its opinion by reason, but the being unchangeable by reason, for he who in every way objects, must in every way be opposed.

Property is, in the next place, subverted, if he who wishes to assign what is naturally inherent, places it after that manner in his discourse, as to signify what is always inherent, since he will seem to have subverted that, which was stated to be the property. Thus, since he who says that the property of man is to be a biped, wishes to assign what is naturally inherent indeed, but signifies in the enunciation what is always inherent, biped would not be the property of man, since not every man has two feet. On the other hand, he confirms it, if he desires to assign the property which is naturally inherent, and signifies it after this manner in his speech, for as to this, property will not be subverted. Thus, since he who assigns the property of man, to be an animal susceptible of science, both desires and also signifies in speech, the property which is naturally inherent, it would not, as regards this, be subverted, as that an animal susceptible of science is not the property of man.

Besides, with regard to such things as are enunciated, as to some other first, or as that which is itself first, it is difficult to assign the property of such as these; for if you assign the property of what is through something else, it will also be verified in respect of what is first, but if you assign the property of the first, it will also be predicated of that which subsists according to something else. Thus, if some one asserts the property of superficies to be coloured, to be coloured will also be verified of body, but if of body, it will also be predicated of superficies; so that of what a sentence is verified, a name is not also verified.

Nevertheless, it happens with some properties, that an error for the most part happens from the want of definition, as to how and of what things the property is assigned. For all men endeavour to assign property, either as what is naturally inherent, as biped of man, or as what is (merely) inherent, as of a certain man to have four fingers, or as in species, as of fire that which is most subtle, or simply, as of animal to live, or through another, as of soul to be wise, or as the first, as of the reasoning faculty to possess prudence, or as in having, as of the scientific to be unconvincible by argument, (for to be unconvincible in argument will be nothing else than to have something,) or from being had, as of science, the being unchanged by reason, or from being participated, as sensation, by animal, (since something else also has sensation as man, but he perceives because he is a participant of animal,) or in consequence of participating, as of a certain animal to live. He errs, therefore, who does not add the word naturally, because what is naturally inherent, it is possible may not be inherent in that, to which it is natural to be inherent, as in a man to have two feet, He, however, who does not distinguish that he assigns what is inherent (errs), because a thing will not be such (sometimes) as it is now, as for man to have four fingers, but he errs who does not show that he assigns it, as what is first, or as through something else, because the name will not be verified of that, of which the definition is, as to be coloured, whether it is assigned as the property of superficies or of body. He, again, who does not previously declare that he assigns property, either from having, or from being had, (errs,) because it will not be property, for it will be inherent, if he assign the property from being had, in that which has, but if from having, in that which is had, as the being unconvincible by reason being laid down as the property of science, or of the scientific man. He, again, who does not, besides, signify (that he assigns property), from a thing partaking or being partaken of, (errs,) because the property will be present with certain other things also; if, indeed, he assign it from being partaken of, it will be present with those partaking it, but if from its partaking, with those which are partaken of, as if to live should be placed as the property of some certain animal, or of animal. (Again he errs), who does not distinguish (that the property is assigned) in species, because it will be present with one thing alone, of those which are under this, of which he assigns the property, for what exists according to excess is present with one thing alone; as of fire, that which is most light. Sometimes, indeed, he who adds the expression "in species" errs, for it will be necessary that there should be one species of the things stated, when the words "in species" are added, but this does not occur in some things, as neither in fire, for there is not one species of fire, since a burning coal, flame, and light, each of them being fire, are specifically different. For this reason, there is no necessity, when the words "in species" are added, that there should be another species of what is stated, because what is assigned as property will be more present with some, but less with others, as of fire that which is most subtle, for light is more subtle than a burning coal, and than flame. Nevertheless, this ought not to happen, when the name is not more predicated of that, of which the sentence is more verified, for otherwise it will not be (true), that of what the sentence is more, the name is also more (predicated.) Moreover, besides these, the same thing will happen to be the property of what is simply, and of what is especially; in what is simply, as the most subtle happens in the case of fire, for this very thing will be property of light also, since light is most subtle. If, therefore, another person should thus assign property, we must argue, but he must not yield to this objection, but straightway, when the property is assigned, define the manner in which he assigns it.

In the next place, property is subverted if a thing is assigned as the property of itself, for what is stated to be, will not be property, since every thing which is the same with a thing, manifests essence, but that which manifests essence is not property, but definition; thus, since he who says that the becoming, is a property of good, assigns that which is the property of itself, (for the good and the becoming are the same,) the becoming, would not be the property of the good. On the other hand, we confirm it, if the same is not assigned as the property of itself, but that which reciprocates is laid down, for what is stated not to be, will be property; e.g. since he who asserts the property of animal is animated substance, does not lay down the same thing as the property of itself, but assigns what reciprocates, animated substance would be the property of animal.

Next, we must consider this in the case of those which consist of similar parts, the subverter indeed whether the property of the whole is not verified of the part, or whether the property of the part is not predicated of the whole, since what is stated to be, will not be property. In some things indeed this occurs, as a man may assign property perty in things of similar parts, sometimes looking to the whole, and sometimes directing his attention to what is enunciated according to a part, yet neither will be rightly assigned. For instance, in the whole of thing; since he who states the property of the sea is an abundance of salt water, introduces the property of a certain thing, consisting of similar parts, but assigns such as is not verified of a part, (for a certain sea does not abound with salt water,) the property of the sea would not be an abundance of salt water. Again, in the case of a part, e.g, since he who states the property of air to be the respirable, asserts the property of a certain thing of similar parts, but assigns such a thing as is verified of a certain air, but is not spoken of all air, (for all is not respirable,) the respirable would not be the property of air. Now he who confirms, (must see) whether of each of the things consisting of similar parts, that is verified, which is the property of them according to the whole, since what is stated not to be, will be property: thus, since it is verified of all earth to tend naturally downward, and this is the property of certain earth according to earth, to tend naturally downward would be the property of earth.

We must next consider from opposites; first, from contraries, the subverter indeed whether the contrary is not the property of the contrary, since a contrary will not be the property of a contrary; thus, since injustice is contrary to justice, but the worst to the best, and the best is not the property of justice, neither would the worst be the property of injustice. On the other hand, the confirmer (must examine), whether the contrary is the property of the contrary, for a contrary will be the property of a contrary; thus, since evil is contrary to good, and what is to be avoided to what is eligible, but the property of good is the eligible, the property of evil would be that which is to be avoided.

Next, from relatives; the subverter indeed if one relative is not the property of another relative, for this relative will not be the property of that relative; thus, since the double is spoken relatively to the half, and the exceeding to the exceeded, but the exceeding is not the property of the double, the exceeded would not be the property of the half. It is confirmed however, if one relative is the property of another, for this relative will be the property of that; thus, since the double is spoken relatively to the half, one indeed with relation to two, but two to one, and the property of the double is as two to one, the property of the half will be as one to two.

Thirdly, it is subverted, if what is predicated according to habit is not the property of the habit, since neither will what is predicated according to privation be the property of privation; also if what is predicated as to privation is not the property of privation, neither will what is predicated as to habit be the property of habit; thus, since privation of sense is not said to be the property of deafness, neither would sensation be the property of hearing. Again, it is confirmed, if what is predicated according to habit is the property of habit, for what is predicated as to privation will be also the property of privation; and if what is predicated as to privation is the property of privation, what is predicated as to habit will be the property of habit. Thus, since it is the property of sight to see, according as we possess sight, not to see, would be the property of blindness, according as we do not possess sight when we are naturally adapted to have it.

Moreover, from affirmatives and negatives, and, first, from the predicates themselves; but this place is useful for the subverter only. Thus, if affirmation, or what is predicated as to affirmation, is the property of a thing, neither negation nor what is predicated as to negation will be the property of it; but if negation, or what is predicated according to negation, is its property, neither affirmation nor what is predicated as to affirmation will be its property; thus, since animated is the property of animal, what is not animated will not be the property of animal.

Secondly, from things predicated or not predicated, and of which they are predicated or not predicated, subverting it indeed if affirmation is not the property, of affirmation; for neither will negation be the property of negation, and if negation is not the property of negation, neither will affirmation be the property of affirmation. Thus, since animal is not the property of man, neither would what is not animal be the property of what is not man, and if what is not animal appears to be not the property of what is not man, neither will animal be the property of man. We confirm it, on the contrary, if affirmation is the property of affirmation, for negation will also be the property of negation, and if negation is the property of negation, affirmation also will be the property of affirmation; thus, since not to live is the property of what is not animal, to live would be the property of animal; and if to live appears the property of animal, not to live will appear the property of what is not animal.

Thirdly, from subjects themselves, subverting indeed if the assigned property is the property of affirmation, since the same will not also be the property of negation; but if what is assigned be the property of negation, it will not be the property of affirmation; thus, since the animated is the property of animal, the animated would not be the property of what is not animal. On the other hand confirming it, if the assigned be not the property of affirmation, for it would be that of negation. This place however is false, for affirmation is not the property of negation, nor negation of affirmation, for affirmation is not wholly present with negation, but negation is with affirmation, yet is not present as a property.

Next, from things oppositely divided, subverting indeed, if none of the oppositely divided is the property of no one of the remaining oppositely divided, since neither will what is stated, be the property of that of which it is stated as the property; thus, since sensible animal is the property of no other animal, intelligible animal would not be the property of God. Again, confirming it, if any one of the remainder oppositely divided, is the property of each of these which are oppositely divided; for the remainder will be the property of that of which it is stated not to be the property; thus, since it is the property of prudence to be naturally per se, the virtue of the reasoning part, and of each of the other virtues thus assumed, the property of prudence would be, to be naturally per se, the virtue of the appetitive part of the soul.

In the next place, from cases, subverting property indeed if case is not the property of case, for neither will one case be the property of the other; thus, since what is beautifully is not the property of what is justly, the beautiful would not be the property of the just. On the other hand, confirming if case is the property of case, for the one case will be the property of the other; thus, since pedestrian biped is the property of man, it would also be the property of man to be called pedestrian biped. Not only however must we observe cases in respect of what has been stated, but also in opposites, as was observed in the former places, subverting indeed if the case of the opposite is not the property of the case of the opposite, for neither will the case of one opposite be the property of the case of another opposite; thus, since what is well (done) is not the property of what is justly done), neither would be ill (done), the property of that which is done unjustly. Again, we confirm it, if the case of the opposite be the property of the case of the opposite, for the case of this opposite will be the property of the case of that opposite; thus, since best is the property of good, worst would be the property of evil.

Next, from those which subsist similarly, subverting, indeed, if what subsists similarly is not the property of what has similar subsistence, for neither will what subsists similarly be the property of that which has similar subsistence. Thus, since the builder of a house subsists similarly with regard to building a house, as the physician with regard to producing health, but it is not the property of the physician to produce health, neither would it be the property of the house-builder to produce a house. It is confirmed, however, if what subsists similarly is the property of what has similar subsistence, for the similarly subsisting will also be the property of what has similar subsistence; thus, since the physician subsists similarly with regard to being effective of health, as the trainer of the gymnasium to the being effective of a good habit of body, but the being effective of a good habit of body is the property of the trainer, to be effective of health would be the property of the physician.

Next, from those which subsist after the same manner, subverting, indeed, if what subsists after the same manner is not the property of what subsists after the same manner, for neither will what subsists after the same manner be the property of what subsists after the same manner, but if of that which subsists after the same manner, that which subsists after the same manner, is the property, it will not be the property of that thing of which it is stated to be the property. Thus, since prudence subsists after the same manner with regard to the honourable and the base, from their being a science of each of them, but to be the science of the honourable is not the property of prudence, it would not be the property of prudence to be the science of the base, but if it is the property of prudence to be the science of the honourable, it would not be the property of it to be the science of the base, since it is impossible that the same thing should be the property of many. For him who confirms, indeed, this place is of no use, for what subsists after the same manner is one thing compared with many.

Next, we subvert it, if what is said to exist is not the property of what is said to exist, since neither will to be corrupted be the property of that which is said to be corrupted, nor to be generated of what is said to be generated. For instance, since it is not the property of man to be animal, neither will to be generated animal, be the property of to be generated man, nor will the corruption of animal, be the property of the corruption of man. After the same manner, we must assume (the argument) from being generated to existence and being corrupted, and from being corrupted to existence and being generated, as was just now said from existence, to the being generated and corrupted. Again, we confirm it, if of what is arranged according to existence, the property is that which is arranged according to the same, for what is said to be according to the being generated, will also be the property of what is said to be according to the being generated, and of what is said to be corrupted that which is assigned according to this. Thus, since to be mortal is the property of man, to be generated mortal would also be the property of the being generated man, and the corruption of mortal of the corruption of man. In the same way, indeed, we must take the argument, both from the being generated and the being corrupted with regard both to existence and to the same from the same, as was observed to him who subverts.

Next, we must pay attention to the idea of the thing proposed, subverting, indeed, if it be not present with the idea, or if not as to this, according to which that is stated, of which the property is a sign, for what is stated to be, will not be the property. Thus, since rest is not present with man himself, so far as he is man, but so far as he is idea, rest would not be the property of man. We confirm it, indeed, if it is present with the idea, and is present so far as it is predicated of this very thing, of which it is stated not to be the property , for what is stated not to be, will be property. Thus, since it is present with animal—itself to be composed of soul and body, and this is present with it, so far as it is animal, to be composed of soul and body would be the property of animal.

Next, from the more and less, first indeed subverting, if the more is not the property of the more, for neither will the less be the property of the less, nor the least of the least, nor the most of the most, nor the simply of the simply. Thus, since to be more coloured, is not the property of what is more body, neither will to be less coloured, be the property of what is less body, nor in short will to be coloured, be the property of body. We confirm it however, if the more is the property of the more, since the less also will be the property of the less, and the least of the least, and the most of the most, and the simply of the simply; for instance, since to perceive more, is the property of what is more vital, to perceive less, would be the property of the less vital, and the most of the most, the least of the least, and the simply of the simply.

From the simply too, the subverter must consider whether the simply is not the property of the simply, for neither will the more be the property of the more, nor the less of the less, nor the most of the most, nor the least of the least; thus, since it is not the property of man to be worthy, neither would to be more worthy, be the property of what is more man. The confirmer however (must consider), whether what is simply is the property of what is simply, for the more will be the property of the more, the less also of the less, the least of the least, and the most of the most; thus, since it is the property of fire naturally to tend upwards, it would also be the property of what is more fire naturally to tend more upwards, and in the same manner we must direct attention from other things also, to all these.

Secondly, it is subverted, if the more is not the property of the more, since neither will the less be the property of the less; thus, since it is more the property of animal to perceive, than of man to know, but it is not the property of animal to perceive, it would not be the property of man to know. We confirm it indeed, if the less is the property of the less, for the more will also be the property of the more; thus, since it is less the property of man to be naturally mild than of animal to live, but it is the property of man to be naturally mild, it would be the property of animal to live.

Thirdly, we subvert it, if it is not the property of which it is more the property, since neither will it be the property of that of which it is less the property, but if it is the property of that, it will not be the property of this. Thus, since to be coloured is more the property of superficies than of body, but it is not the property of superficies, neither would to be coloured be the property of body; if however it is the property of superficies, it would not be the property of body. This place indeed is not useful to the confirmer, since it is impossible that the same thing should be the property of many.

Fourthly, it is subverted if what is more the property (of the thing), is not its property, since neither will what is less its property be the property, e. g. since the sensible is more the property of animal than the partible, but the sensible is not the property of animal, the partible would not be the property of animal. But it is confirmed if what is less its property is the property of it, since what is more its property will be the property; thus, since it is less the property of animal to perceive than to live, but to perceive is the property of animal, to live would be the property of animal.

Next, from things which exist similarly, first indeed subverting, if what is similarly the property, is not the property of that of which it is similarly the property, since neither will what is similarly property be the property of this of which it is similarly the property. Thus, since it is similarly the property of the appetitive part of the soul to desire, and of the reasoning part to reason; but to desire is not the property of the appetitive part, neither would to reason be the property of the reasoning part. On the other hand, we confirm it, if what is similarly property is the property of this of which it is similarly the property; for what is similarly property will be the property of this thing of which it is similarly the property. For instance, since what is primarily prudent is similarly the property of the reasoning part, and what is primarily temperate of the appetitive part, but what is primarily prudent is the property of the reasoning, the primarily temperate would be the property of the appetitive part.

Secondly, we subvert it, if what is similarly the property (of a thing) is not its property, since neither will what is similarly property be the property of it. Thus, since it is similarly the property of man to see and to hear, but to see is not the property of man, neither would the property of man be to hear. Again, we confirm it, if what is similarly the property (of a thing) is its property, for what is similarly its property will be the property; thus, since it is similarly the property of the soul that a part of it should be appetitive primarily and argumentative, but it is the property of the soul that a part of it is primarily appetitive, it would be the property of the soul that a part of it is primarily argumentative.

Thirdly, it is subverted, if it is not the property of what it is similarly the property, since neither will it be the property of what it is similarly the property, but if it is the property of that, it will not be the property of the other. Thus, since to burn is similarly the property of flame and of a burning coal, but it is not the property of flame to burn, neither would it be the property of a burning coal to burn, but if it is the property of flame, it would not be the property of a burning coal: this place however is of no use to him who confirms.

Nevertheless, (the place) from things similarly affected, differs from that from things similarly inherent, because the one is assumed according to analogy, and is not considered in respect of something being inherent, but the other is compared from something being inherent.

Next, property is subverted indeed, if he who assigns it in capacity, assigns also that property in capacity, to that which is not; capacity being by no possibility present with a non-entity, for what is laid down to be, will not be, property. Thus, since he who says the property of air is that which may be breathed, assigns property in capacity, (for a property of this kind is that which is capable of being breathed,) but also assigns the property to that which is not; for although an animal should not exist, which is naturally capable of breathing the air, yet the air may exist, though if animal is not, it is not possible to breathe; hence a thing of such a kind as that it may be breathed, will not then be the property of air, when there will not be such an animal as can breathe, wherefore what may be breathed would not be the property of air.

Again, we confirm it, if he who assigns it in capacity either assigns the property to that which is, or to that which is not, when capacity may be present with what is not, since what is stated not to be property, will be property. Thus, since he who assigns as the property of being, the ability to suffer or to act, assigning property in capacity, has assigned property to being, (for when being is, it will also be able to suffer, or to do, something,) hence ability to suffer or to act, would be the property of being.

Next, it is subverted, if it is placed in hyperbole, since what is laid down to be, will not be property. For it happens to those who thus assign property, that the name is not verified in respect of what the sentence is verified, since the thing being corrupted, the sentence will nevertheless remain, for it will especially be present with something existing; thus, if some one should assign the property of fire to be the lightest body, for when fire is corrupted, there will be a certain body, which will be the lightest, so that the lightest body would not be the property of fire. It is confirmed however, if the property is not placed in hyperbole, for as to this, the property will be well stated, e.g. since he who states the property of man, to be an animal naturally mild, does not assign property in hyperbole, so far as regards this, the property would be well stated.

There are five parts of the discussion of definition, for (the latter is reprehended), because it is not altogether true to assert that the sentence (is predicated) of what the name is; (since it is necessary that the definition of man, should be verified of every man;) or because when there is a genus, it does not place the thing defined in the genus, or not in its appropriate genus; (for it is necessary that the person defining, placing the thing defined in genus, should add the differences, since of things in the definition, genus especially seems to signify the substance of the thing defined;) or because the sentence is not proper; (since it is necessary that definition should be proper, as was before observed;) or if, though it has effected all the things stated, it does not define, nor state, what the nature is, of the thing defined. The remainder is, besides what we have mentioned, if it is defined indeed, but not defined well.

Whether, then, the sentence also is not verified of what the name is, must be observed from places belonging to accident, since there also the whole consideration is, whether it is true or not true, for when we show by discussion that accident is inherent, we say that it is true, but when that it is not inherent, (we call it) untrue. Whether, again, the assigned definition is not placed in its proper genus, or is not proper, must be observed from places spoken about genus and property.

It remains, then, to declare how we must institute an inquiry, whether a thing is not defined, or whether it is not rightly defined; first, indeed, then we must see whether it is not rightly defined, since it is easier to do any thing (merely), than to do it well. Now it is clear that an error is more frequent about this, because it is more difficult, so that reasoning about this is easier than about that.

Of the (question of defining) not rightly, there are two parts, one whether obscurity is employed in the interpretation, (since it is necessary that the person defining should make use of the clearest possible interpretation, as definition is assigned, for the sake of knowledge,) and the other, whether he has stated the definition more extensively than is requisite, as every thing added in the definition is superfluous. Again, each of the above-named is divided into many parts.

One place, then, belonging to the obscure is, if what is stated is equivocal with any thing, as that generation is a leading to substance, and that health is the harmony of hot and cold, for (the words) leading and harmony are equivocal, therefore it is doubtful which of the things signified, by what is multifariously predicated, a person wishes to assert. In like manner also, if when the thing defined is multifariously predicated, a person expresses himself without distinction, as it will be dubious of what he has given the definition, and it is possible to cavil, as if the definition were not adapted to every thing of which he has given the definition. Now, such a thing it is especially possible to do, when there is latent equivocation, and also it is possible, when a person has distinguished in how many ways what is assigned in the definition is predicated, to form a syllogism: for if it is not sufficiently stated in any mode, it is clear that it has not been defined according to that mode.

Another (place is), if it is spoken metaphorically, for instance, that science is that which cannot fall, or that the earth is a nurse, or that temperance is symphony, as everything enunciated metaphorically is obscure. It is also possible for him who uses a metaphor to cavil that he has spoken rightly, for the given definition will not suit, e. g. in the case of temperance, since all symphony is in sounds. Besides, if symphony be the genus of temperance, the same thing will be in two genera not containing each other, since neither does symphony contain virtue, nor virtue symphony.

Moreover, (the definition is obscure,) if established names are not used, as Plato calls the eye, that which is shaded by the eyebrows, or a spider, a feeder on putrescence, or the marrow, bone-begetter, since whatever is unusual, is obscure.

Some things, however, are asserted neither equivocally, nor metaphorically, nor properly, for instance, law (defined as) a measure, or an image of things naturally just. Such things, indeed, are worse than metaphor, for metaphor in some way makes known what is signified on account of similitude, as all who use metaphors do so according to a certain similitude, but this kind of thing does not make known, as neither is there any similitude, according to which law is a measure or an image, nor is it accustomed to be predicated properly. Wherefore, if a person says that law is properly a measure or an image, he speaks falsely, for an image is that, the generation of which is by imitation, but this does not exist in law: but if it is improperly, it is clear that he speaks obscurely, and worse than any thing spoken metaphorically.

Again, (it is reprehended,) if from what is stated, the definition of the contrary is not evident, since they who well define, signify also the contraries besides: or if it is not of itself evident of what the definition is spoken; but such cases, like ancient pictures, cannot be known, what each is, without a superscription.

If then definition be obscure, we must examine from such places as these, but if it has been stated excessively, we must first see whether any thing is employed which is present with all things, or simply with beings or with those which are under the same genus with the thing defined; since it must inevitably happen that this will be asserted in excess. For it is requisite to separate genus from other things, but difference from something of those in the same genus, wherefore what is present with all things is simply separated from nothing, but what is present with all under the same genus is not separated from those in the same genus, so that an addition of this kind is vain.

Or (we must observe), whether what is added be proper, but this being taken away the remaining definition is proper, and demonstrates substance, e. g. in the definition of man, receptive of science is superfluously added, since this being taken away, the remaining definition is appropriate, and manifests the substance. In a word, every thing is superfluous, which when taken away the remainder causes the thing defined to be manifest, such indeed is the definition of the soul, if it be number moving itself, for that which itself moves itself is soul, as Plato has defined it. Or is what has been mentioned property indeed, yet does not manifest essence when number is taken away? In what way then the thing is, is hard to explain, but we must use (this place) in all such things as may be expedient. For instance, that the definition of phlegm is, the first unconcocted moisture from food, for there is one first, not many, so that the addition of unconcocted is superfluous, since when this is taken away, what remains will be the proper definition, since it is impossible that this and something else, should be the first (moisture) arising from food. Or shall we say that phlegm is not simply the first thing from food, but the first of things unconcocted, so that unconcocted must be added, for if it is stated in that way the definition will not be true, since it is not the first of all things.

Moreover, (we must examine) whether some one of the things in the definition, is not present with all those under the same species, since such is defined worse than they do, who use that which is present with all substances. For in that way the remainder would be the proper definition, and the whole would be proper; since, in short, if any thing true is added to property, the whole (definition) becomes proper. If however something of those in the definition is not present with all those under the same species, it is impossible that the whole definition should be proper, since it will not be reciprocally predicated of the thing, e. g. an animal pedestrian biped of four cubits, for such a definition is not reciprocally predicated of the thing, from four cubits not being present with all those, which are under the same species.

Again, whether the same thing is frequently stated, as he who says, that desire is the appetite of the pleasant, for all desire is of the pleasant; wherefore what is the same with desire will also be of the pleasant, the definition then of desire is the appetite of the pleasant, for there is no difference between saying desire or the appetite of the pleasant, so that each of these will belong to the pleasant. Or is it that this is not at all absurd? for man also is a biped, so that what is the same with man will also be biped, but an animal pedestrian biped is the same as man, so that animal pedestrian biped is biped. Nevertheless, no absurdity happens on this account, for biped is not predicated of pedestrian animal, (for thus indeed biped would be twice predicated of the same thing,) but biped is predicated about animal pedestrian biped, wherefore biped is predicated once only. In the same manner, in the case of desire, for to be of the pleasant is not predicated of appetite, but of the whole (sentence), so that here also the predication is once. Still, that the same name should be twice pronounced does not belong to absurdity, but frequently to predicate the same about a certain thing, as when Xenocrates says that prudence is definitive and contemplative of beings, for the definitive is something contemplative, so that he twice says the same thing, again adding contemplative. They also do the same, who say that refrigeration is a privation of natural heat, for all privation is of what exists naturally, so that to add naturally, is superfluous, but it would have been sufficient to say privation of heat, since privation itself makes it known that it is spoken of what is naturally.

Again, whether what is universally asserted adds also something particular, as if (we defined) equity the diminution of things profitable and just, for the just is something profitable, wherefore it is contained in the profitable, so that just is superfluous, and speaking of the universal, the partial is added. Also, if (some one should define) medicine to be the science of things healthful for animal and man, or law to be the image of things naturally beautiful and just, for the just is something beautiful, so that he would say the same thing frequently.

Whether therefore (a thing be defined) well or ill, must be examined through these and similar (places), but whether (a person) has asserted and defined what a thing is or not, from the following.

First, if he has not made the definition through things prior and more known. For since definition is assigned for the sake of knowing what is said, but we know not from things casual, but from what are prior and more known, as in demonstrations, (for thus all doctrine and discipline subsists,) it is clear that he who does not define through such things as these, does not define (rightly). But if not, there will be many definitions of the same thing, since it is evident that whoever defines through things prior and more known, defines in a better manner, so that both definitions would be of the same thing; this however does not seem so, as to each being, to be what it is, is one thing, so that if there should be many definitions of the same thing, there will be the same essence of the thing defined, as is manifested by each of the definitions. These (essences) however are not the same, since the definitions are different, wherefore he has evidently not defined, who does not define through things prior and more known.

To assume then that a definition is not framed through things more known, is possible in two ways, either if (it is) simply from things more unknown, or from those which are more unknown to us, for in both ways it is possible. Simply then the prior is more known than the posterior, as a point than a line, and a line than a superficies, and a superficies than a solid, as also unity than number, for it is prior to, and the principle of, all number; likewise a letter than a syllable. Nevertheless, to us, the reverse sometimes happens, since a solid falls under sense rather than a superficies, but a superficies more than a line, and a line more than a point, for the multitude know these things in a greater degree, since some things it is possible for any casual intellect to discern, but others belong to an intellect accurate and transcendent.

Simply then, it is better to aim at the knowledge of things posterior through such as are prior, for a thing of this kind is more scientific; still by those who are incapable of knowing through things of this kind, it is perhaps necessary to frame the definition through things known to them. Now of such definitions, are those of a point, and of a line, and of a superficies, for all manifest things prior, through such as are posterior, for they say that one is the boundary of a line, the other of a superficies, and the other of a solid. Still we must not be unmindful that those who define thus, cannot denote what the nature is of the thing defined, unless the same thing should happen both to be more known to us, and simply to be more known, since he who well defines must necessarily do so, through the genus and the differences, but these are of the number of things more known simply than, and prior to, species. For genus and difference co-subvert species, so that these are prior to species. They are also more known, for if species is known, it is necessary that genus also and difference should be known, (as he who knows man, knows both animal and pedestrian,) but when genus or difference is known, it is not necessary that species also should be known, wherefore species is more unknown. Besides, to those who really call things of this kind, definitions, which consist of what are known to every one, it will happen to say that there are many definitions of the same thing, since some things are more known to some persons, and not the same to all, so that there would be a different definition to be given to each person, if it were necessary that definition should be framed from things more known to each severally. Further, to the same persons at a certain time, certain things are more known, at first indeed sensibles, but the reverse when they become more accurate, so that neither would the same definition have to be given to the same person, by those who say that a definition must be given through things more known to each. Clearly, then, we must not define through such things, but through those that are simply more known, since thus only would one and the same definition be always produced. Perhaps indeed what is simply known is not that which is known to all, but that (which is known) to those who have their intellect well disposed, just as what is simply wholesome is that which is so, to those whose bodies are in a good state. Hence it is necessary accurately to explain each of these, and to use them in discussion as may be expedient, but most confessedly is it possible to subvert definition, if it be neither framed from things simply more known, nor from those (which are so) to us.

One mode then (of proving) that it is not through things more known, is when the prior is manifested through the posterior, as we observed before; another, if the definition of what is at rest and definite, is a sign to us through the indefinite and through what is in motion, since the permanent and definite are prior to the indefinite, and to what is in motion.

The modes indeed (of showing a definition to be) not from things prior, are three, first, if the opposite is defined through the opposite, as good through evil, for opposites are naturally simultaneous. Still to some there seems to be the same science of both, so that the one is not more known than the other; nevertheless, we must bear in mind that some things perhaps it is impossible to define otherwise, as the double without the half, and whatever things are enunciated relatively per se, for in all these there is the same essence from their having relation in a certain respect spect, so that it is impossible to know the one without the other, wherefore in the definition of the one, the other must of necessity be comprehended. All such things, then, it is necessary to know, and to employ them as may appear useful.

Another (place) is, if in the definition the thing defined is used, but this is latent when a person does not employ the very name of the thing defined, as if he should define the sun to be a star apparent by day, for using day, he uses sun. In order to detect such, we must take the definition instead of the name, as the day is the motion of the sun above the earth; for it is clear that he who speaks of the motion of the sun above the earth, mentions the sun, so that he who uses day, uses sun.

Again, if what is in an opposite division is defined by what is in an opposite one, as the odd to be what is greater than the even, by unity: for things oppositely divided from the same genus are naturally simultaneous, but the odd and even, are divided oppositely, since both are differences of number.

Similarly also if the superior is defined through the inferior, as that the even number is what may be divided into two parts, or that good is the habit of virtue; for the expression, "into two parts," is assumed from two, which is an even number; virtue also is a certain good, so that these are under those. Besides, it is necessary that whoever uses the inferior should use also (the thing defined) itself; for both he who uses virtue uses good, since virtue is a certain good, and likewise also he who uses "in two parts" uses the even, because a division into two parts, signifies to be divided into two, but two is an even number.

Universally then, one place is, that a definition is not framed through things prior and more known, but the particulars of it are such as have been mentioned. The second place is, if when a thing is in genus it is not placed in genus, but in all such, an error occurs in the definition of which, what a thing is, is not previously declared; for instance, the definition finition of body as having three dimensions, or if any one should define man to be that which is cognizant of number. For it has not been stated what that is which has three dimensions, or what it is which is cognizant of number; but genus would signify what a thing is, and is the first thing supposed, of those predicated in the definition.

Besides, if when the thing defined belongs to many things, it is not adapted to all, as if some one should define grammar to be the science of writing what is dictated; for (the words) and of reading also, are wanting, since he has no more defined grammar, who defines it to be the art of writing, than he who states it to be the art of reading, so that neither defines, but he who states both of these, since there cannot be many definitions of the same thing. In some instances then, the case is really as we have stated, but in others it is not, as in those which do not essentially belong to both; thus, medicine (is the science) of producing disease and health, for of the one it is said (to be the science) essentially, but of the other accidentally, as to produce disease is simply foreign from medicine. Wherefore he does not more define, who refers to both, than he does who refers to one, of these, but perhaps even in a worse manner, since any other person is able to produce disease.

Besides, (he errs,) who does not refer to the better, but to the worse, when there are many things, to which that defined, belongs, since every science and faculty seems to belong to what is best.

Again, whether what is asserted is not placed in its proper genus, must be observed from the elements belonging to genera, as we stated before.

Moreover, if stepping over, he speaks of genera, as he who (defines) justice to be a habit productive of equality, or distributive of the equal, for when he thus defines, he passes over virtue. Omitting then the genus of justice, he does not state what its nature is, for the essence of every thing is connected with the genus. This however is the same thing with not placing it in the nearest genus, for he who places it in the nearest, has mentioned all the superior, since all the superior genera are predicated of the inferior. Hence, it must either be placed in the nearest genus, or he must add all the differences, through which the nearest genus is defined, to the superior genus; for thus he will have omitted nothing, but instead of a name, will have mentioned the inferior genus, in the definition. Whoever, on the other hand, speaks of the superior genus alone, does not mention also the inferior genus, for the one who calls a thing a plant, does not state it to be a tree.

Again, we must in like manner consider with regard to differences, whether those of genus are introduced, for unless a person defines by the proper differences of a thing, or altogether asserts what can be the differences of nothing, as animal or substance, he evidently does not define, since the things stated are not the differences of any thing. Observe also, whether any thing is divided oppositely to the difference stated, for if there is not, what is stated will evidently not be the difference of genus, since every genus is divided by differences oppositely divided, as animal by the pedestrian and winged, by the aquatic and biped. Or if indeed there is an oppositely divided difference, which however is not verified of the genus, since evidently neither would be the difference of genus, as all oppositely divided differences are verified of their proper genus. Likewise, if it is indeed verified, but (the difference) when added to genus does not produce species, since it is evident that this would not be the specific difference of genus, as every specific difference united with genus produces species; but if this be not the difference, neither will that which was mentioned, since it is divided oppositely to this.

Moreover (he errs), if he divides genus by negation, as those who define a line to be length without breadth, since this signifies nothing else than that it has no breadth; the genus then will happen to partake of the species, for every length is either with, or without breadth, since of every thing either affirmation or negation is verified, so that the genus of a line which is length, will either be without breadth, or will have breadth. But length without breadth is the definition of the species; likewise, length with breadth, for without breadth and with breadth are differences; but the definition of species is from the difference and the genus; so that genus would receive the definition of species; in like manner also, the definition of difference, since one of the above-named differences is necessarily predicated of genus. The place mentioned however is useful against those who assert that there are ideas, for if there is length itself, how will it be predicated of the genus that it has breadth or has it not, for it is necessary that one of these should be verified of every length, if it is to be verified of the genus. This however does not occur, since there are lengths without breadth, and those which have breadth, so that this place is useful against those only, who say that genus is one in number, and this they do who admit ideas, for they say that length itself and animal itself are genera.

Perhaps, indeed, in some cases it is necessary for a person when defining, to use negation, as in privations, for that thing is blind which has not sight when it is naturally adapted to have it. Still it makes no difference whether we divide genus by negation, or by such an affirmation, as to which it is necessary that negation should be oppositely divided; for instance, if length were defined to be that which has breadth, for to what has breadth that which has not breadth, is oppositely divided, but nothing else, so that the genus is again divided by negation.

Again (observe), whether species is assigned as difference, as they do who define contumely to be insolence with derision, for derision is a certain insolence, so that derision is not difference, but species.

Moreover, whether genus is assigned as difference as that virtue is a good or worthy habit, for good is the genus of virtue; or is good not a genus, but a difference, since it is true that the same thing cannot possibly be in two genera which do not comprehend each other? For neither does good contain habit, nor habit good, since not every habit is good, nor every thing good, a habit; hence they would not both be genera. If, then, habit be the genus of virtue, it is evident that good is not the genus, but rather the difference; besides, habit signifies what the virtue is, but good does not signify what, but what kind of thing it is; indeed difference, seems to signify quality.

Observe, also, whether the assigned difference does not signify quality, but this particular thing; since every difference appears to signify a certain quality.

Consider, also, whether difference is accidentally present with the thing defined, for no difference is of the number of things accidentally present, as neither is genus, since it is not possible that difference should be present with a certain thing, and not be present.

Moreover, if difference or species be predicated of genus, or something which is the subject of species, there will not be a definition, for nothing of what we have mentioned can possibly be predicated of genus, since genus is the most extensively spoken of all. Again, if the genus is predicated of the difference, for genus seems to be predicated not of difference, but of those of which difference (is predicated); thus, animal of man, and ox, and other pedestrian animals, and not of difference itself, which is spoken of species. For if animal were predicated of each of the differences, many animals would be predicated of the species, for differences are predicated of species. Again, all differences will either be species or individuals if they are animals, since each animal is either species or individual.

Likewise, we must observe, whether species or some one of those under species, is predicated of difference, for this is impossible, since difference is more widely predicated than species; further, difference will happen to be species, if a certain species is predicated of it, for if man is predicated (of difference), man is evidently a difference. Again, (see) whether difference be not prior to species, since difference must necessarily be posterior to genus, but prior to species.

Observe, too, whether the assigned difference is of another genus, neither contained by, nor containing it, as the same difference does not appear to be of two genera not comprehending each other. Otherwise, the same species would happen to be in two genera not comprehending each other, since each difference introduces its own appropriate genus, as pedestrian and biped co-introduce animal; wherefore, if each of the genera be predicated of what the difference is, it is evident that the species is in two genera not comprehending each other. Or is it not impossible that there should be the same difference of two genera not comprehending each other, but it must be added, neither are both under the same? For pedestrian animal, and winged animal, are genera not comprehending each other, and biped is a difference of both these, wherefore, it must be added, that neither are both under the same, for both of these are under animal. It is evident, also, that difference need not always introduce its appropriate genus, since there may be possibly the same (difference) of two genera not comprehending each other, but it is necessary that it should co-introduce one alone, and those which are above it, as biped, winged, pedestrian, co-introduce animal.

Observe, also, whether to be in a certain thing is assigned as the difference of substance, for substance does not seem to differ from substance in being some where, wherefore also, those are to be blamed, who divide animal by pedestrian and aquatic, as if pedestrian and aquatic signified being some where. Or are they not rightly blamed in these things? for the aquatic does not signify the being in something or some where, but a certain quality, since it would be similarly aquatic, if it should even be in a dry place; likewise, also, the terrestrial, even in a moist place, will be terrestrial and not aquatic; at the same time, if ever difference signifies the being in a certain thing, it is evident that (he who defines) will err.

Again, (notice) whether passion is assigned as difference; for every passion, when increased, alters the essence, but difference is not a thing of this kind, but difference appears rather to preserve that of which it is the difference, and it is simply impossible for any thing to be without its proper difference, since pedestrian not existing, there will not be man. In a word, nothing of those, according to which the thing possessing it, is changed in quality, is the difference of it, for all such, when increased, alter the essence, so that if any one assigns a certain difference of this kind, he errs, as, in short, we are not changed in quality, according to differences.

He also (mistakes), who assigns the difference of a certain relative, not with reference to something else; for of relatives, the difference is also a relative, as in the case of science, for it is said to be contemplative, practical, and effective; but each of these signifies relation, since it is contemplative of something, and effective, and practical of something.

Examine, also, whether he who defines, assigns that to which each relative is naturally adapted, for some things can only be employed for that to which each relative is naturally adapted, but for nothing else, some, on the other hand, for something else also; thus, the sight is (employed) for seeing only, but some one may draw up a weight, even with a strigil; notwithstanding, whoever should define a strigil an instrument for drawing would err, for it is not naturally adapted to this; the definition however of what a thing is naturally adapted to, is that for which a prudent man, so far as he is prudent, would use it, also the science which properly belongs to each.

Further, (examine) whether or not, the (definition) is assigned of what is first, when it happens to belong to many things, e.g. that prudence is the virtue of man, or of the soul, and not of the reasoning part, for prudence is the virtue of the reasoning part primarily, since according to this, both the soul and man are said to be prudent.

Again, he errs, unless that is receptive of which the thing defined is stated to be the passion, or disposition, or something else; for every disposition and every passion is naturally generated in that of which it is the disposition or passion, as science in the soul, being a disposition of the soul. Sometimes indeed men mistake in these things, as they do who say that sleep is the impotency of sense, and that doubt is the equality of contrary arguments, and that pain is a separation accompanied with violence, of connascent parts; for neither is sleep present with sense, which it ought to be if it is the impotency of sense, likewise neither is doubt present with contrary arguments, nor pain with connascent parts, for things inanimate would suffer pain, since pain would be present with them. Such also is the definition of health if it is the harmony of hot and cold, for it is necessary that things hot and cold should be in health, since the harmony of each, is in those of which it is the harmony, so that health would be in them; besides, by those who thus define, it happens that the thing made is reduced to the maker, or contrariwise, for neither is the separation of connascent parts, pain, but is productive of pain, nor is the impotency of sense, sleep, but one is effective of the other, for either we sleep in consequence of becoming powerless, or we become powerless in consequence of sleep. Likewise, also, the equality of contrary arguments would appear productive of doubt, for when in reasoning on both sides of a question, every thing appears to us to have equal weight on either side, then we doubt which we shall adopt.

Moreover, we must consider according to all times, whether there is any discrepancy, e. g. if one defined the immortal, to be what is now an incorruptible animal, for the animal now incorruptible will be now immortal. Or does this not happen in this case, for to be now incorruptible is ambiguous, for it either signifies that it is not now corrupted, or that it cannot now be corrupted, or that it is now a thing of that kind which can never be corrupted. When therefore we say that the animal is now incorruptible, we say this, that it is now such an animal, as never to be corrupted, and this would be the same with immortal, so that it does not happen that it is now immortal. Nevertheless, if it should happen that what is assigned according to the definition is now, or was before, inherent, but what is according to the name is not inherent, it will not be the same: wherefore this place must be used as we have stated.

It must also be considered whether the thing defined is enunciated by some others, rather than by that definition which was assigned, as if justice (should be defined) a power distributive of the equal. For he is rather a just man who deliberately chooses to distribute the equal, than he who is able, so that justice would not be a power distributive of the equal, since he would be especially just, who is most able to distribute the equal.

Moreover, whether the thing receives increase, but what is assigned according to the definition does not receive it, or on the contrary, what is assigned according to the definition receives, but the thing, not. For it is necessary that both should receive it or neither, if indeed what is assigned according to the definition is the same with the thing. Again, whether both indeed receive increase, yet both do not simultaneously receive accession, as if love is the desire of congress; for he who loves in a greater degree is not more desirous of congress, so that both do not simultaneously receive increase, which they should if they were the same.

Again, (examine) whether when two things are proposed, of what the thing (defined) is more predicated, that which is according to definition is less predicated, as if fire is the most subtle body; for flame is more fire than light, yet flame is less the most subtle body than light; it would be necessary however that both should in a greater degree be present with the same thing, if they were the same. Again, (notice) whether the one is similarly present with both things proposed, but the other not similarly with both, but in a greater degree with one of them.

Besides, whether a person accommodates the definition to two things, according to each, as if the beautiful (should be defined) what is pleasant through sight or through hearing, and being, that which is able to suffer or to act; for the same thing at one and the same time will be beautiful and not beautiful; likewise also will be being and not being. For what is pleasant through hearing will be the same with the beautiful, so that what is not pleasant through hearing will be the same with what is not beautiful, since opposites to the same are the same; but what is not beautiful is opposed to what is beautiful, and what is not pleasant through hearing to what is pleasant through hearing. It is clear then, that what is not pleasant through hearing is the same with what is not beautiful; if then any thing is pleasant through the sight, but not through the hearing, it will both be beautiful and not beautiful, and similarly we may show that the same thing is both being and non-being.

Again, when framing definitions of genera and differences, and of all other things assigned in definitions instead of names, consider whether there is any discrepancy.

If indeed what is defined should either be per se, or generically, a relative, consider whether that to which it is referred, either per se, or generically, has not been mentioned in the definition, as if some one had defined science to be immutable opinion, or the will, appetite unattended with pain. For the essence of every relative consists in a relation to something else, since the being of every thing which subsists with reference to another thing, is the same with that of being in a certain respect referred to something; wherefore it is necessary to say that science, is the opinion of the object of science, and the will, the appetency of good. Likewise, also, if a person defined grammar to be the science of letters, since it will be necessary in the definition to assign that to which the thing defined, or to which the genus, is referred. Also (consider), whether the definition of a certain thing referred to something, is not assigned with reference to the end; now the end in each thing is that which is best, or on account of which other things subsist, wherefore, either what is best, or what is last, must be stated; e. g. that desire is not of the pleasant, but of pleasure, for we even choose the pleasant for the sake of this.

Examine, moreover, whether that to which a thing is referred, be generation or energy, since nothing of this kind is an end; for to have energized, or to have been generated, are rather the end, than to generate or to energize, or is it not that such a thing as this is true in all, for almost all men rather desire to be delighted than to cease being delighted, so that they rather make the end to energize than to have energized?

In some cases again, (we must notice) whether there is not a definition of the quantity or quality, or the where, or according to the other differences; for instance, what the quality or quantity is of the honour, which the ambitious man desires; for all desire honour, so that it is not sufficient to say that he is ambitious who desires honour, but we must add the above-mentioned differences. Likewise, also, the quantity of riches which the avaricious man desires (must be mentioned), or what quality of pleasure the incontinent man seeks after, for he is not said to be incontinent who is vanquished by any pleasure whatever, but he who is so, by a certain one. Or again, as men define night, the shadow of the earth, or an earthquake, the motion of the earth, or a cloud, the condensation of the air, or wind, the motion of the air, for the quantity, quality, the where, and by what, must be added. In like manner, as to other such things, since he who omits any difference whatever, does not state what is the very nature of the thing; indeed we must always argue against what is wanting, for neither will an earthquake be the motion of earth in any manner, nor in any quantity, as neither will wind be the motion of air in any manner, nor in any quantity.

Moreover, in (defining) appetites, (there will be an error), if what appears is not added, and in as many other things as this is adapted to; for instance, that the will is the appetency of good, but desire the appetency of the pleasant, yet not of what appears good or pleasant. For oftentimes it escapes those who aspire after a thing that it is good or pleasant, so that it is not necessary that it should be good or pleasant, but only that it should appear to be so, wherefore it is necessary that the explanation should be made in this manner. If, on the other hand, what has been mentioned should be assigned, whoever asserts that there are ideas, must be led to ideas, since idea is not of any thing apparent, but form seems to be referred to form, thus desire itself is of the pleasant itself, and the will itself of the good itself. Now it will not be of the apparent good, nor of the apparent pleasant, since that a thing should be self-apparent good or pleasant is absurd.

Moreover, if there be the definition of a habit, take notice of what possesses it, but if the definition be of what possesses, consider the habit, and in like manner with regard to other things of this kind; e. g. if the pleasant is what is beneficial, he also who is pleased is benefited. In a word, it happens after a certain manner in such definitions, that the definer defines more things than one, since he who defines science, after a certain way defines ignorance also, likewise the scientific and the unscientific, also to know and to be ignorant, for the first being evident, the rest also in some way become evident. We must examine then, in all such cases, lest any thing should be discordant, employing the elements which are from contraries, and conjugates.

Examine too, in relatives, whether to what genus is referred, to that a certain species is referred, for instance, if apprehension to the object of apprehension, a certain apprehension also (is referred) to a certain object of apprehension, and if the multiple is to the sub-multiple, whether a certain multiple is to a certain sub-multiple, since if there is not such reference, there has been evidently an error.

Again, observe whether there is an opposite definition of the opposite, as whether the definition of the half is opposite to that of the double, since if the double be that which surpasses in the equal, the half will be what is surpassed in the equal. Likewise, also, in the case of contraries, for the definition of the contrary will be contrary according to one certain connexion of contraries, thus, if that is beneficial which is productive of good, what is productive of evil or is corruptive of good is injurious, since one of these must necessarily be contrary to that mentioned at first. If then neither be contrary to that mentioned at first, it is clear that neither of the definitions afterwards given, can be the definition of the contrary, so that neither has the definition given at first been rightly given. Nevertheless, since some contraries are said to be so, from the privation of another, as inequality seems the privation of equality, (for things are called unequal which are not equal,) it is clear that what is stated to be contrary as to privation, is necessarily defined through the other, but that it is no longer (necessary) that what remains (should be defined) through what is predicated as to privation, for each would happen to become known through each. We must pay attention, therefore, to such an error as this in contraries, as if some one should define equality to be the contrary to inequality, since it is defined through what is predicated according to privation. Further it is necessary that he who thus defines should use the thing defined, which indeed will be evident if the definition be assumed instead of the name, for there is no difference between saying inequality or the privation of equality, wherefore, equality will be the contrary to the privation of equality, so that the thing itself (defined) will be employed. Still if neither contrary should be predicated according to privation, but the definition similarly assigned, as that good is what is contrary to evil, it is evident that evil will be what is contrary to good, since of things thus contrary, the definition must be similarly assigned. Wherefore, again, the thing defined happens to be employed, as good is inherent in the definition of evil, so that if good is what is contrary to evil, but there is no difference between evil and the contrary to good, good will be that which is contrary to the contrary of good, so that the person has evidently used the thing itself.

Further, (remark) whether he who assigns what is predicated according to privation, has not assigned that of which it is the privation; for instance of habit, or of contrary, or of whatever it is the privation; or whether he has not added that in which it is naturally adapted to be generated, either simply, or in which first, it is adapted to be generated. Thus if stating ignorance to be privation, a person has not said that it is a privation of science, or has not added in what it is naturally adapted to be produced, or having added it, has not assigned in what first, as that it is not in the reasoning faculty, but in man or soul, for if he has not done some one of these, he commits an error. So also if he should not have said that blindness is privation of sight in the eye, for it is requisite that he who well assigns what (privation) is, should also assign of what it is the privation, and again, what that is, which is deprived.

Observe, also, whether a person has defined by privation, that which is not predicated according to privation, which fault they will appear to commit in the definition of ignorance, who do not speak of ignorance according to negation. For that which has not science does not seem to be ignorant, but rather that which is deceived, hence we neither say, that inanimate things nor children are ignorant, so that ignorance is not predicated according to the privation of science.

Again, (examine) whether similar cases of the definition agree with similar cases of the noun, for instance, if the beneficial is what produces health, whether beneficially be productively, and that was beneficial, which was productive of health.

Besides observe, whether the definition stated accords to the idea, since in some things this does not happen, as when Plato in his definition of animals, adds "mortals," for idea will not be mortal; for instance, man-self, wherefore the definition will not suit the idea. In short, it is necessary that the definition of those things to which the effective or the passive is added, should be discrepant with the idea, since ideas appear to those who say that there are ideas, to be impassive and immoveable, and against these such arguments are useful.

Yet further, in things predicated equivocally, (observe) whether a person has assigned one common definition of them all. For those are synonymous, of which there is one definition according to the name, wherefore the assigned definition is of no one of those (contained) under the name, since, indeed, the equivocal similarly suits every thing. The definition given by Dionysius, of life, has this fault, if it be the motion innate and consequent of a nourished genus, for this is not more inherent in animals, than in plants, but life does not seem predicated as to one species, but one kind of life to be inherent in animals, and another in plants. Therefore it is possible on purpose to assign a definition thus, as if all life were synonymous and predicated of one species, yet nothing prevents a man while he sees the equivocation, and wishes to assign the definition of the other, from being ignorant, that he does not assign a proper definition, but one common to both: notwithstanding, he will no less err if he has framed it in either way. Since, indeed, some equivocations escape us, the interrogator ought to use them as synonyms, (as the definition of the one will not be adapted to the other, so that it will appear in a way not to have been defined, as the synonymous ought to suit every thing,) on the other hand, the respondent must distinguish by division. Still since some respondents say, that the synonymous is equivocal, when the assigned definition does not suit every thing, but that the equivocal is synonymous if it suit both; it must be previously acknowledged, or previously inferred of these, that they are equivocal or synonymous, whichever they may be, since they more readily concur who do not foresee the result. Nevertheless, if they cannot agree, but some one should say that the synonymous is equivocal, because the assigned definition does not suit this, observe whether the definition of this, accords also to the rest, as it is evident it will be synonymous with the rest. If not, however, there will be many definitions of the remainder, since two definitions according to the name, accord to them, viz. both the prior and the posterior assigned. Again, if a person having defined any of those multifariously predicated, the definition also not suiting all, should not indeed say that it is equivocal, but should deny that the name suits all, because the definition does not, against such a one we may say that it is necessary to use that appellation which has been delivered and received, and not to disturb such things; nevertheless, some must not be enunciated in a way similar to the multitude.

If the definition of some connected thing should be given, consider, taking away the definition of one of the things connected, whether the remaining (definition) be that of what remains, for if not, neither it is evident will the whole be of the whole. Thus, if some one defined a finite straight line to be the boundary of a superficies having boundaries, of which the middle covers the extremities, if the definition of a finite line is the boundary of a superficies having boundaries, it is necessary that the remainder should be that of a straight line, of which the middle covers the extremities. Yet an infinite has neither middle nor extremities, but is nevertheless straight, so that the remainder is not the definition of the remainder.

Moreover (observe), if when what is defined is a composite, the definition is assigned consisting of as many members as the thing defined; now a definition is said to be of an equal number of members, when there are as many nouns and verbs in the definition as there are composites. For it is necessary in such cases, that there should be a change of the names, either of all, or of some of them, since there are no more names stated now than before; still it is requisite that he who defines should give a sentence instead of names, of all, if possible, but if not, of most things. For thus also in simple things, he who changes the name will have defined, as, for instance, (if he should say) vestment instead of garment.

Besides there is a greater error, if a person has made a change for names more unknown for instance, a white mortal instead of a white man, for neither is there a definition, and what is stated thus, is less clear.

Examine also in the change of names, whether he does not signify still the same thing, as when a person states that contemplative science is contemplative opinion, for opinion is not the same with science, at least indeed it must be, if the whole is to be the same, for contemplative is common in both definitions, but what remains is different.

Further, when a person changes one of the names, observe whether a change is made, not of the difference, but of the genus, as in the instance just now stated, since contemplative is more unknown than science, as the one is genus, and the other difference, and genus is most known of all, so that he ought to have made the change not of the genus, but of the difference, since this is the more unknown. Or is this reproof ridiculous, as there is nothing to prevent difference from being signified by a name most known, but genus not? but if this is the case, it is clear that we must make a change, as to the name of genus, and not of difference. Nevertheless, if (a person) does not assume a name for a name, but a sentence instead of a name, it is clear that he must give the definition of difference rather than of genus, since definition is given in order to make a thing known, for difference is less known than genus.

If however the definition of difference is assigned, examine whether the assigned difference is common to any thing else, as when it is said that an odd number is a number which has a middle, it must be defined in addition, how it has a middle. For number is common in both definitions, but instead of odd, a sentence is assumed; yet both a line and a body have a middle, though they are not odd numbers, so that this would not be the definition of the odd. Still, if that which has a middle be multifariously predicated, we must explain besides, how it possesses a middle, so that there will be either a reproof or a syllogism, that (the thing) has not been defined.

Again (observe), if that of which the definition is the sign, belongs to the number of beings, but what is under the definition does not; e. g. if white is defined colour mixed with fire, for it is impossible that the incorporeal should be mixed with body, so that it could not be colour mixed with fire, yet it is white.

Moreover, those who in (the definition of) relatives do not distinguish to what reference is made, but speak, comprehending many things, either wholly or in part enunciate falsely, as if some one should say that medicine is the science of being. For if medicine is the science of nothing which exists, it is evident that (the definition) is wholly false, but if it is of one, but not of another, it is partly false; for it is necessary (to be the science) of every thing, if it is said to be the science of being per se, and not accidentally, as is the case with other relatives, since every object of science is referred to science. Likewise, also in other things, since all relatives reciprocate. Besides, if he who explains a thing not per se, but accidentally, rightly explains it, each relative would not be referred to one, but to many things, as there is nothing to prevent the same thing, being both white, and good, so that he who explains by reference to one of these, would rightly explain, if he who explains from accident, does so rightly. Moreover, it is impossible that such a definition as this, should be peculiar to the thing assigned, for not only medicine, but many other sciences are referred to what exists, so that each will be the science of being; wherefore it is clear that such is the definition of no science, for it is necessary that definition should be peculiar, and not common.

Sometimes indeed, they define not the thing (only), but a thing in a good condition, or perfect; such is the definition of a rhetorician, and of a thief, since a rhetorician is one who is able to perceive what is persuasive in each thing, and to omit nothing; but a thief is one who takes on the sly, for it is evident that each being such, will be good, the one a good rhetorician, but the other a good thief, for not he who pilfers secretly is a thief, but he who wishes to pilfer secretly.

Again, (he errs,) who assigns what is of itself eligible, as practical or efficient, or in any way eligible on account of something else; as if he said that justice, is the preserver of the laws, or that wisdom, is effective of felicity, for what is effective, or preservative, is of the number of things eligible on account of something else. Or does nothing prevent what is eligible for itself, being eligible for something else also? nevertheless, he errs, who thus defines what is eligible per se, since in every thing, the best especially subsists in the essence, but it is better to be eligible per se, than on account of something else, so that definition ought of necessity rather to signify this.

Consider besides, whether he who assigns the definition of a certain thing, defines that it is these things, or that which consists of these, or this together with that; for if (it should be) those things, it would happen to be present with both, and with neither, as if he defined justice to be temperance and fortitude; for if when there are two, each has one of these, both will be just, and neither; since both indeed will possess justice, but each of them, not possess it. If however what has been said, be not very absurd from a thing of this kind happening in others also, (since nothing prevents two persons having a mina, though neither of them has,) yet that contraries should be present with the same, would appear to be altogether absurd. Nevertheless, this would occur if one of them has temperance and timidity, but the other, fortitude and intemperance, for both will have justice and injustice; for if justice be temperance and fortitude, injustice will be timidity and intemperance. Briefly, whatever arguments may be brought to prove that the parts and the whole are not the same, are all useful for what has now been stated, since he who thus defines, seems to say that the parts are the same as the whole. Still the arguments are especially appropriate in whatever the composition of the parts is evident, as in a house and other such things; for it is evident that when the parts exist, there is nothing to prevent the whole from not existing, so that the parts are not the same with the whole.

If, on the other hand, he should say that the thing defined is not these, but something consisting of these, we must first examine whether one certain thing, is not naturally adapted to be produced from these, for some things are so subsistent in relation to each other, as that nothing is produced from them, for instance, a line and number. Besides, whether the thing defined is naturally adapted to be in some one first, but those of which a person says that it (the thing defined) consists, are not in some one first, but each in the other, since it is clear that the thing would not consist of these, as in what the parts are inherent, it is necessary that the whole also should be inherent, so that the whole would not be in one first, but in many. Still if the parts and the whole are in one first, consider whether they are not in the same, but the whole in one, and the parts in another. Again, whether the parts are destroyed together with the whole, since it is necessary that it should happen vice versâ, the parts being destroyed that the whole should perish, but the whole being destroyed it is not necessary that the parts also should be destroyed. Or whether the whole be good or evil, but the parts neither, or vice versâ the parts indeed good or evil, but the whole neither, for neither is it possible that any good or evil should be produced from neither, nor that neither should be produced from evil or good. Or whether the one be more good than the other is evil, but what consists of these be not more good than evil; for instance, if impudence (should be said to consist) of fortitude and false opinion. For fortitude is more a good, than false opinion is an evil, wherefore it is necessary that what results from these, should be consequent to the more, and should either be simply good, or more good than evil. Or indeed is this unnecessary, unless each be good or evil, per se, for many effective things are not per se, good, but when mingled; or on the contrary each of them is good, but when mingled is evil, or neither (good nor evil). What has been now stated is especially apparent in the case of things wholesome and hurtful, since some drugs are of such a nature as that each is good, but if both be given mixed together, (the compound is) bad.

Again, (consider whether a thing be stated to consist) from the better and the worse, of which the whole is not worse than the better, but is better than the worse; or is neither this necessary, unless those of which the thing consists, be of themselves good? for there is nothing to prevent the whole not being good, as in the instances just now adduced.

Besides, whether the whole be synonymous with the other part, which it ought not to be, as neither is it in syllables, for a syllable is synonymous with no one of the elements of which it consists.

Moreover, (observe) whether a person has explained the mode of composition. For it is not sufficient to a knowledge of a thing, to say that it consists of these, because not merely to consist of these, but to consist of them in this manner, is the essence of composites; as in the case of a house, for the composition of these in any way whatever, is not a house.

If again this thing is assigned together with that, we must first state that this is with that, or is the same with these, or because this is from those; for he who says, honey with water, either says honey and water, or what consists of honey and water, so that whichever of these he allows to be the same as this with that, the same things it will be suitable to say, as were before urged against each of these. Further, distinguishing in how many ways one thing is said to be with another, consider whether this be in no way with that; e. g. if it is said that one is with another, either as in one same recipient, as justice and fortitude in the soul; or in the same place or time, but what is asserted as to these, should be by no means true, the assigned definition would, it is evident, not be the definition of any thing, as this is by no means with that. If, however, when the things are distinguished, it is true that each is in the same time, examine whether it is possible that each may not be referred to the same thing; as if (some one) should define fortitude to be daring joined with right conception, for it is possible for a man to have the daring to defraud, yet a right conception about things wholesome; still he is not yet a brave man, who has this, together with that, in the same time. Again, if both are referred to the same thing, as to things medical, since nothing prevents a man's having boldness and right conception about medical concerns, yet nevertheless he is not a brave man who possesses this with that; for neither ought each of them to be referred to different things, nor to any thing casually the same, but to the end of fortitude, as to warlike dangers, or if there be any thing more the end, than this.

Some indeed, of those thus explained, by no means fall under the above-mentioned division, as if anger is pain, joined with a notion of being despised: for this would show that pain arises from a notion of this kind, but that any thing should exist on account of this, is not the same as for this to be with that, according to any of the modes stated.

Moreover, if (a person) has stated the whole to be a composition of these, as that animal is a compound of soul and body, first observe, whether he has not stated the quality of the composition; as it defining flesh or bone, he should say that it is a compound of fire, earth, and air. For it is not enough to say it is a compound, but it must also be defined of what quality it (the compound) is, since flesh is not produced from the composition of these in any way whatever, but flesh, from things composed in this way, and bone, from those in that. It seems likely, indeed, that neither of those mentioned is altogether the same with composition, as to all composition, dissolution is contrary, but nothing to any of those stated; besides, if it is similarly probable, that every or no compound, is composition, but each animal being a compound is not composition, neither will any other compound be composition.

Again, if in like manner contraries are naturally adapted to be in something, and it has been defined through one of them (alone), there has evidently not been a definition. Otherwise, indeed, there will happen to be many definitions of the same thing, for what more does he state who has defined through this, than he who has done so through the other, since both are in a similar manner naturally adapted to be in it? such, indeed, is the definition of the soul, if it is an essence capable of science, for it is equally capable of ignorance.

Notwithstanding, if a person has it not in his power to argue against the whole definition from the whole not being known, he must attack some part, if it should be known, and apparently not be well assigned, since the part being subverted, the whole definition also, is subverted. (It is also requisite) correcting and reforming such definitions as are obscure, in order to render something evident, and to obtain an argument, to consider in this way: since it is necessary for the respondent, either to admit what is taken up by the interrogator, or himself to unfold what that is which is signified by the definition. Yet more, as men are accustomed in assemblies to introduce a law, and if what is introduced be better, they abrogate the former law, so we must act in definitions, and another definition must be introduced, since if (this) appear better, and more to develope the thing defined, it is evident that the definition laid down (previously) will be subverted, since there are not many definitions of the same thing.

Nevertheless, it is not the least element as to all definitions, to define with oneself sagaciously the thing proposed, or to take up a definition which has been well framed; since it is necessary, running as it were to an example, to survey what is deficient in the definition, and what is superfluously added, so as to be better provided with arguments.

Let, then, so much suffice for those points which pertain to definitions.

Whether a thing be the same or different, according to the most proper of the before-mentioned modes about the same thing, (and that was said to be most properly the same, which is one in number,) we must consider from cases, co-ordinates and opposites. For if justice be the same with fortitude, a just man is also the same with a brave man, and justly with courageously. So also with opposites, for if these be the same, the opposites to these also are the same, according to any of the modes of opposition stated, since it makes no difference whether we take an opposite to this or that, as they are the same. Again, from efficients and corruptives, also from generations, corruptions, and in short, from things which subsist similarly with reference to either, for whatever are simply the same, the generations and corruptions also of these are the same, and besides, the efficients and corruptives.

Examine also, whether of those things of which one is especially said to be a certain thing, another also is especially predicated according to the same; as Xenocrates shows that a happy and a worthy life are the same, because a worthy and a happy, are the most eligible of all lives, for the most eligible, and the greatest, are one thing. Likewise, in other things of the same kind; yet it is necessary that each of those which are said to be the greatest, or the most eligible, should be one in number, otherwise it will not be demonstrated that it is the same, since it is not necessary, if the Peloponnesians and the Lacedæmonians are the bravest of the Greeks, that the Peloponnesians should be the same with the Lacedæmonians, as a Peloponnesian and a Lacedaemonian are not one in number. Still it is requisite that one should be contained under the other, as Lacedæmonians under Peloponnesians, otherwise it will happen that they are better than each other, if the one be not comprehended under the other, for it is necessary that the Peloponnesians should be better than the Lacedæmonians, if the one be not contained under the other, for they are better than all the rest (of the Greeks). So also it is necessary that the Lacedæmonians should be better than the Peloponnesians, for these also are better than all the rest, so that they are better than each other. It is clear then, that what is said to be best, and greatest, ought to be one in number, if we would show that it is the same, for which reason also Xenocrates does not demonstrate, for a happy, and a worthy life, are not one in number, so that it is not necessary they should be the same, because both are most eligible, but that one should be under the other.

Again consider, whether one (of the things proposed) is the same (as a third thing), also whether another (is the same with it), for if both are not the same with it, it is clear that (they are not the same) with each other.

Moreover, observe from the accidents of these, and from those things to which these are accidents, since whatever are accidents to the one, must of necessity be also accidental to the other, and to what one of them happens, the other must also happen; now if any discrepancy subsists amongst these, they are evidently not the same.

Notice also, whether both are not in one genus of category, but the one denotes quality, the other quantity or relation; again, whether the genus of each is not the same, but the one is good, and the other evil, or the one virtue, and the other science: or whether the genus is indeed the same, yet there are not the same differences predicated of each, but of the one, that it is contemplative science, of the other, that it is practical, and so of other things.

Further, from the more, if one indeed receives the more, but the other not, or if both indeed receive it, yet not at the same time; thus he who loves more, does not more desire intercourse, so that love, and the desire of intercourse, are not the same.

Besides, from addition, if each being added to the same, does not make the whole the same, or if the same being taken away from each, the remainder is different; as if some one said, that the double of the half, and the multiple of the half, were the same. For the half being taken away from each, the remainder ought to signify the same, yet it does not, for the double, and the multiple, do not denote the same.

Observe however, not only whether any impossibility now happens on account of the thesis, but also whether it is possible to be from the hypothesis pothesis; as (happens) to those who say that a vacuum, and a plenum of air, are the same, since it is clear that if the air should depart, there will not be a less, but a greater vacuum, yet there will no longer be a plenum of air. Hence, a certain thing being supposed, whether false or true, (it makes no difference,) one of them is subverted, but the other not, hence they are not the same.

In a word, from those things which are in any way predicated of each, and of which these are predicated, we must consider if there be any discrepancy; for whatever are predicated of the one, ought likewise to be predicated of the other, and of which the one, is predicated, it is necessary that the other also, should be.

Besides, since the same thing is predicated multifariously, examine whether after some other mode they are the same, since it either is not necessary, or not possible that those which are the same in species or genus, should be the same in number, but we will investigate whether they are the same in this way, or not in this way.

Again, whether the one can possibly be without the other, for they would not be the same.

The places then pertaining to the same thing, are said to be so many, but it is clear from what has been stated, that all places belonging to the same thing, which are subversive, are useful also to definition, as was observed before; for if both the name, and the definition, do not denote the same, it is evident that the proposed sentence will not be a definition. On the other hand, none of the confirmative places is useful to definition, since it is not sufficient to show that what is under definition, and name, is the same thing, in order to confirm definition; but definition must necessarily possess all those other things which have been mentioned.

To subvert definition then, we must make our attempt always in this manner, and through these things; but if we desire to confirm, it is first necessary to know, that no one, or few, of those who discuss, syllogistically infer definition, but all assume such sort of thing, as a principle; for instance, both those who are conversant with geometry and numbers, and other such instructions: next, that it is the business of another treatise accurately to assign both what definition is, and how it is necessary to define, but now only so much must be observed, as is sufficient for our present purpose, viz. that it is possible there may be a syllogism of definition, and of the very nature of a thing. For if definition be a sentence denoting the very nature of a thing, and it is necessary that things predicated in the definition should alone be predicated in (reply to) what a thing is, but genera and differences are predicated in reply to this question, it is evident that if any one assumes those things only to be predicated in reference to what a thing is, that the sentence which contains these, will evidently be a definition, since there cannot be possibly another definition, as nothing else is predicated of the thing, in reference to what it is.

Evidently then, there may be a syllogism of definition, but from what we ought to construct it, has been more accurately determined in other places; these same places, however, are useful for the proposed method. For in contraries, and other opposites, we must observe whole sentences, observing them also, according to parts; as if the opposite (be the definition) of the opposite, it is necessary that what is stated, should be of the thing proposed. Since however, there are many connexions of contraries, we must select from them, that definition which especially appears contrary; whole sentences then, must be considered in the manner stated, but according to parts, thus. In the first place, (it must be shown) that the assigned genus is rightly assigned, for if the contrary be in the contrary genus, but the thing proposed is not in the same, it will clearly be in the contrary (genus), since contraries must of necessity either be in the same, or in contrary genera. We also think that contrary differences are predicated of contraries, as of white and black, for the one is dissipative, the other is collective of vision. Wherefore, if contraries are predicated of a contrary, the assigned (differences) would be predicated of the thing proposed, so that since both genus and differences are rightly assigned, it is evident that what is assigned, will be a definition. Or it is not necessary that contrary differences should be predicated of contraries, unless they should be contraries in the same genus, yet of those of which the genera are contrary, there is nothing to prevent the same difference being predicated of both; e. g. of justice and injustice, for the one is a virtue, but the other a vice of the soul, so that the word "of the soul," being a difference, is predicated of both, since there is of the body also, a virtue and a vice. Nevertheless, this at least is true, that the differences of contraries are either contrary or the same; if then a contrary be predicated of a contrary, but not of this, it is evident that the difference adduced, will be predicated of this. In short, since definition consists of genus and differences, if the definition of the contrary be manifest, the definition also of the thing proposed, will be manifest. For as what is contrary, is either in the same, or in a contrary genus, and likewise either contrary or the same differences, are predicated of contraries, it is evident, that the same genus will be predicated of the thing proposed, which was also of the contrary; but the differences are contrary, either all or some, yet the remainder are the same, or on the contrary, the differences are the same, but the genera are contrary, or both genera and differences are contrary, for both cannot possibly be the same, or else there will be the same definition of contraries.

Besides, (we must argue) from cases, and conjugates, since genera must of necessity follow genera, and definitions be consequent to definitions: thus, if oblivion be the loss of science, to become oblivious, will be to lose science, and to have forgotten, to have lost science; any one then of the before-mentioned particulars being admitted, the rest must necessarily be admitted. Likewise, also, if destruction be a dissolution of substance, to be destroyed will be for substance to be dissolved, and destructively will be dissolvingly, and if what is destructive is dissolvent of substance, destruction is a dissolution of substance; similarly also, of other things, wherefore any one being assumed, all the rest will be conceded.

Also, (we must argue) from things which subsist similarly as to each other; for if the salubrious is productive of health, the productive of a good habit will be effective of a good habit, and the beneficial will be productive of good. For each of the above named, subsists similarly with regard to its proper end, so that if the definition of one of them, is to be effective of the end, this will also be the definition of each of the rest.

Moreover, from the more and the similar, in as many ways as it is possible to confirm, comparing two with two, thus; if this is more the definition of that, than something else of another thing, but the less is a definition, the more also (will be a definition); also if this is similarly the definition of that, and another thing of something else, if the one is a definition of the other, the remainder will also be of the remainder. When however, one definition is compared with two things, or two definitions with one, the consideration from the more is of no use, as neither can there possibly be one definition of two things, nor two of the same.

Those which have already been stated, and also the others from cases and conjugates, are the most appropriate places; wherefore we ought especially to retain these, and to have them at hand, since they are most useful to the greatest number (of problems). Of the rest also, those which are especially common, for these are the most efficacious of the remaining ones; as, for instance, to regard singulars, and to consider in species, whether the definition is suitable, as species is synonymous. Such however is useful against those who lay down that there are ideas, as was before observed; moreover, whether a name is introduced metaphorically, or whether the same thing is predicated of itself as different, and if there be any other place common and efficacious, we must employ it.

That it is more difficult to confirm, than to subvert definition, is evident from what will next be said, since it is not easy for him (who interrogates) to perceive and take from those who are interrogated, propositions of this kind; as that of the things in the assigned definition, one is genus, but another difference, and that genus and differences are predicated (in reply) to what a thing is. Still without these there cannot possibly be a syllogism of definition, as if certain other things also are predicated of a thing, in respect of what it is, it is dubious whether what is stated, or something else, is its definition, since definition is a sentence signifying what is the very nature of a thing. Now it is evident from what follows, for it is more easy to conclude one, than many things. To the subverter indeed, it is sufficient to dispute against one (part of the definition), (for having subverted any one part, we shall have subverted the definition,) but it is necessary for the confirmer, to prove that all those things are inherent, which are in the definition. Moreover, the confirmer must adduce an universal syllogism, since it is requisite that of every thing of which a name is predicated, the definition should be predicated, and besides this, vice versâ, if the assigned definition is to be proper. On the other hand, it is not requisite for the subverter to demonstrate the universal, since it suffices to show that the definition is not verified of any one of the things under the name, if also it should be necessary to subvert universally, neither thus, is reciprocation necessary in subversion, for it is enough that the subverter show universally, that the definition is not predicated of some one of those things, of which the name is predicated. On the contrary, it is not necessary to show that the name is predicated, of what the definition is not predicated. Further, if also it is present with every thing under the name, yet not with it alone, the definition will be subverted.

In like manner, it is with regard to property and genus, since in both, it is easier to subvert, than to confirm. About property then, it is evident from what we have stated, as for the most part property is assigned in conjunction, so that it is possible to subvert by taking away one (word); but he who confirms, must of necessity conclude every thing by syllogism. Now almost every thing else, which may be said of definition, will also be suitable to say of property, since the confirmer ought to show that it is inherent in every thing under the name, but it suffices for the subverter to show it non-inherent in one thing; if also it is inherent in every thing, but not in it alone, thus too, it becomes subverted, as was observed about definition. Concerning genus indeed, (it is evident,) because it is necessarily confirmed only in one way, if a person shows it present with every individual; nevertheless, it is subverted in two ways, for both if it has been shown not present with any, and not with a certain one, what was assumed in the beginning is subverted. Moreover, it is not enough, for the confirmer to show that it is inherent, but also it must be shown that it is inherent, as genus; but to the subverter it is enough to show it non-inherent, either in a certain or in every individual: still it seems, as in other things, to destroy, is easier than to produce, so in these, subversion, is easier than confirmation.

In the case of accident, we can more easily subvert, than construct the universal, for the confirmer must show that it is present with every, but the subverter need only show it non-inherent in one. On the contrary, it is easier to confirm, than to subvert the particular, as it suffices for the confirmer to show it present with a certain one, but the subverter must show that it is present with none.

It appears also clear why it is the easiest thing of all, to subvert definition, for many things being asserted in it, very many are given; but from the greater number, a syllogism is more quickly made, since it is likely that error should arise in many, more than in few, things. Moreover, it is possible to argue against definition through other things also, since whether the sentence be not appropriate, or whether what is assigned be not genus, or something of those in the definition be non-inherent, the definition will be subverted; but against other things, neither can we assume those arguments which are derived from definitions, nor all others, since those only which belong to accident, are common to all the particulars mentioned. For it is necessary that each of the things stated should be inherent, if however genus is not inherent as property, the genus will not yet be subverted; likewise, also property need not be inherent as genus, nor accident as genus or property, but merely inherent. Wherefore it is impossible to argue from some things to others, except in definition; hence, it is evident that to subvert definition is the easiest thing of all, but to confirm it the hardest, since we must syllogistically infer all those particulars, and besides these, that the sentence denotes the very nature of a thing, and it is necessary to do this well.

Among other things, property is especially a thing of this sort, for it is easier to subvert it, from its consisting, for the most part, of many things, and it is most difficult of confirmation, because we must combine many things, and besides, show that it is inherent in this alone, and reciprocates with a thing.

Of all however, the easiest is to confirm accident, for in others, not only inherency, but inherency thus, must be shown; but as to accident it suffices to show its inherency only. On the other hand, accident is the hardest to subvert, because the fewest things are given in it, for it is not signified in accident, over and above other things, how it is inherent, so that subversion is possible in two ways; as to the rest, either by showing non-inherency, or non-inherency in this way; but in accident, it is impossible to subvert, except by showing that it is not inherent.

The places then, through which we shall be well provided with arguments against the several problems, have almost sufficiently been enumerated.

We must next speak about order, and in what manner it is necessary to interrogate. In the first place then, he who is about to interrogate, should discover a place whence he may argue; secondly, he should interrogate and arrange the several particulars to himself; thirdly and lastly, he should advance them against another person. Now as to the discovery of the place, its consideration pertains alike to the philosopher and to the dialectician; but how to arrange these, and to interrogate, is the peculiar province of the dialectician, since the whole of this refers to another person ; but to the philosopher, and to him who investigates by himself, it is no concern, if the particulars through which the syllogism is constructed, be true and known, whether the respondent admits them or not, because of their nearness to the original question, and from their foreseeing the result; they even perhaps would endeavour that axioms should be especially known and approximate, as from these, scientific syllogisms subsist.

The places then, whence we must derive (arguments), have been enunciated before, but we must speak of order, and interrogation, distinguishing the propositions which are to be assumed, besides such as are necessary. Now those are called necessary, through which a syllogism arises, but those assumed besides these, are four; for (they are so), either for the sake of induction that the universal may be granted; or for amplifying what is said; or for concealment of the conclusion; or for greater perspicuity of expression. Besides these however, we must assume no proposition, but endeavour through these to increase, and to interrogate: those which are for concealment (are to be assumed) for the sake of contention, yet since the whole of this treatise is with reference to another person, it is necessary to use these also.

The necessary (propositions) then through which a syllogism arises, must not be advanced immediately, but we must retire to what is highest; for instance, not requiring it to be granted, that there is the same science of contraries, if it is desired to assume this, but of opposites, for when this is laid down, it will be syllogistically inferred that there is the same of contraries also, since contraries are opposites. If, again, (a person) does not admit this, we must assume it through induction, proposing contraries particularly, for we must assume the necessary propositions either through syllogism, or through induction, or some by induction, but others by syllogism; such however as are very perspicuous, we shall propose (straightway), for the result is always more obscure in receding and induction; and at the same time, it is easy for him to propose those which are useful, who cannot assume them in that way. Such as have been enumerated besides these, we must assume for the sake of these, but use each in this way; inducing from singulars to the universal, and from things known to those unknown; those however are more known, which are according to sense, either simply, or to the multitude. He however who conceals, must prove by pro-syllogisms those things through which there will be a syllogism of the original (proposition), and these as many as possible, which will happen if a person not only collects syllogistically, necessary propositions, but some one from among such as are useful to these. Again, we ought not to mention the conclusions, but afterwards conclude them in a body; for thus he (the interrogator) will recede farthest from the original thesis. In a word, it is requisite that he who secretly interrogates, should so question, that when the whole assertion has been questioned, and the conclusion is announced, it may be asked why it is so. Now this will be particularly done through the before-mentioned mode, for when the last conclusion only is mentioned, it will not be evident how it results, from the respondent not foreseeing from what the inference would be drawn, the previous syllogisms not having been dissected, but the syllogism of the conclusion would be least of all dissected, when we do not lay down its assumptions, but those by which the syllogism arises.

Moreover, it is useful to take the axioms from which the syllogisms arise, not continuously, but alternately mixed with the conclusions, for when the appropriate ones are placed by each other, the result from them will be more evident.

It is right also, to assume in the definition, as far as we can, an universal proposition, not in the things themselves, but in their conjugates, for (the respondents) deceive themselves by paralogism, when the definition is assumed in the conjugate, as if they did not grant the universal; e. g. if it should be necessary to assume that the angry man desires vengeance on account of apparent contempt, and anger should be assumed to be the desire of vengeance on account of apparent contempt, for it is evident when this is assumed, we should have the universal, which we prefer. Where however, it is proposed in the very things themselves, it frequently happens that the respondent rejects it, because he has rather the objection to it; e. g. that the angry man does not desire vengeance, for we are angry with our parents, and yet do not desire vengeance. Perhaps therefore, this objection is not enough, as in some things it is sufficient vengeance only to grieve, and to produce repentance, nevertheless it has something persuasive, in order that what is proposed, may not seem to be denied without reason: to the definition however, of anger, it is not similarly easy to find an objection.

Again, (we ought) to propose as if we did not propose on account of the thing itself, but for the sake of something else, for (respondents) are cautious of such things as are useful against the thesis. In short, as much as possible the (interrogator) ought to render it obscure, whether he desires to assume the thing proposed or the opposite, for when what is useful against the argument is doubtful, they rather lay down that which seems true to them.

Moreover, we must interrogate through similitude, for the universal is persuasive and more latent; for instance, that as there is the same science and ignorance of contraries, so also there is the same sense of contraries, or on the contrary , since there is the same sense, there is also the same science. This, indeed, is like, yet not the same as, induction, for there the universal is assumed from singulars, but in similars, what is assumed is not universal, under which, all the similars are contained.

Again, it behoves him sometimes to object to himself, since the respondents have no suspicion towards such as appear to argue justly, and it is also useful to say besides this, that such a thing is what is usually asserted, since they are reluctant to change what is usual when they have no objection; at the same time, because they use such things themselves they are careful not to change them. Besides, (we must) not be earnest, although the thing be altogether useful, for men make greater opposition against persons in earnest; also (we should) propose as by comparison, for what is proposed on account of something else, and is not of itself useful, men rather admit. Again, we must not propose that, which ought to be assumed, but that to which this is necessarily consequent, for men more readily concur, from the inference from this not being similarly manifest, and when this. is assumed that also, is assumed. In the last place, let the interrogator ask that, which he wishes especially to assume, for (the respondents) will at first especially deny, because most interrogators assert those things first, about which they are most in earnest. Against some however, propose such things first; since those who are difficult to be persuaded, concede at first, especially if the result is not perfectly apparent, but at the last they assent with difficulty; likewise, also, they who think themselves acute in answering, for admitting many things, at last they make use of sophistical arguments, as if the conclusion did not follow from the things laid down, but they allow readily, trusting to habit, and apprehending that they will suffer no inconvenience. Moreover, we must extend the discourse and insert things which are of no use to it, as they do, who write falsely, for when there are many things, it is dubious in which consists the falsity, wherefore sometimes also, interrogators escape notice, proposing secretly, things which proposed by themselves, would not be admitted.

For concealment then, we must use the thing stated, but for ornament, we must employ induction and division of things homogeneous. What kind of thing then induction is, is clear, but division is one of such a kind, as that one science is better than another, either from its being more accurate, or from its belonging to better subjects; and that of sciences, some are theoretical, others practical, but others effective, for each thing of this kind adorns a speech, yet it is not necessary that it should be adduced, in order to the conclusion.

For the sake of perspicuity, we must adduce examples and comparisons; examples indeed appropriate, and from which we derive information, such as Homer, not as Chœrilus (employs), for thus, what is proposed will be more perspicuous.

In disputation we must employ syllogism with dialecticians, rather than with the multitude, but induction, on the contrary, rather with the multitude, concerning which also we have spoken before. Still, in some cases, he who makes an induction may question the universal, but in others this is not easy, from a common name not being laid down in all similitudes, but when it is necessary to assume the universal, they say it is thus in all such particulars; yet it is one of the most difficult things to define this, viz. which of those adduced are, and which are not, such. Wherefore in disputation they oftentimes circumvent each other, some asserting that those which are not similar are similar, but others doubting whether similars are not similars. On this account, in all such cases he (the disputant) must endeavour to assign a name, so that it may neither be possible for the respondent to doubt, as if what is adduced is not similarly stated, nor for the interrogator to find fault, as if it were similarly stated, since many things which are not similarly stated, appear to be so.

When, an induction being made in many things, a person does not grant the universal, then it is fair to demand the objection; he however who does not state in what this occurs, does not justly demand in what it is not so, for he ought, having first made an induction, thus to demand the objection. It must be claimed too, that the objections be not alleged in the thing itself, which is proposed, unless there should be only one such thing, as the dual alone is the first of even numbers, since it is necessary that the objector should bring the objection in something else, or should state that this alone is a thing of such a sort. As to those indeed, who object to the universal, yet do not allege the objection in the same (genus), but in the equivocal, (as that some one may have not his own colour, or foot, or hand, for a painter may have colour, and a cook a foot, not his own,) employing division in such things, the interrogation must be made, since from the equivocation escaping notice, he will appear to object rightly to the proposition. Still if the objector impede the interrogation, by objecting not in the equivocal, but in the same genus, it is necessary by removing that, in which the objection consists, to bring forward the remainder, making it universal, until what is useful is assumed. Thus, in the case of oblivion and of having forgotten, for they do not allow that he who has lost knowledge, has forgotten, because the thing failing, he has lost indeed knowledge, yet has not forgotten removing: then that, in which the objection consists, we must assert the remainder, as if, the thing remaining, he has lost knowledge, (we must say) that he has forgotten. Likewise, also, against those who object that a greater evil is opposed to a greater good, for they advance this, that to health being a less good than good bodily habit, a greater evil is opposed, since disease is a greater evil than cachexy, therefore in this case also we must take away that in which the objection consists, for when it is removed, the person would more readily concede, as that a greater evil is opposed to a greater good, unless one thing co-introduces another, as a good bodily habit, does health. Still, not only must this be done when there is an objection, but also if without an objection there should be a denial, from foreseeing something of this kind, since when that is removed in which the objection lies, (the objector) will be obliged to concede from his not foreseeing in the remainder, as to what particular thing it is not so, but if he should not concede when he is asked for his objection, he will not be able to allege it. Propositions indeed of this kind are such as are partly false and partly true, for in these it is possible, when we have taken away, to leave the remainder true; nevertheless, if (when interrogating), he proposes in many things, (the other) does not adduce an objection, concession must be claimed, since the proposition is dialectic, against which thus subsisting in many things there is not an objection.

When we can syllogistically infer the same thing, both without and through the impossible, it signifies nothing to him, who demonstrates, and does not dispute, whether the syllogism be in this, or in that way, but a syllogism through the impossible must not be used by him, who disputes against another. For no doubt can exist, if he syllogizes without the impossible, but when the impossible is inferred, except the falsity be very evident, they say that it is not impossible, so that the interrogators do not obtain what they desire.

It is necessary indeed to propose such as subsist thus in many things, but the objection either is not at all, or is not easily perceived, since not being able to see where it is not so, men admit a thing as being true.

Yet we ought not to make the conclusion a question, for otherwise the (respondent) denying, a syllogism does not appear to have been framed. For frequently they deny when the person does not question, but infers as a consequent, and doing this, they do not appear to confute, to those who do not see that, it happens from the things laid down; when then he interrogates, not asserting that the conclusion follows, but the other denies, a syllogism does not entirely appear to have been framed.

Neither does it seem that every universal is a dialectic proposition, as "what is man?" or "in how many ways is good predicated?" since a dialectic proposition is one, to which we can answer either yes or no, which is impossible to those above-named. Hence, such interrogations are not dialectic unless the person speaks by defining or dividing, as; "is good predicated in this or in that way?" for the answer to such things is easy either by affirmation or denial. Wherefore we must endeavour to set forth such propositions in this way, and at the same time it is perhaps just to ask him in how many ways good is predicated, when the (interrogator) divides and proposes, but he (the respondent) by no means concedes.

Nevertheless, whoever questions for a long time one reason, interrogates badly, for if he who is interrogated answers the question, it is evident that (the querist) asks many or oftentimes the same questions, so that he either trifles or has not a syllogism, since every syllogism is from a few things; but if he does not answer, why does he not reprove him, or depart?

Notwithstanding, it is difficult to attack, and easy to maintain, the same hypothesis; such are those which are first and last naturally, for those which are first require definition, but the last are concluded through many things, by him who wishes to assume continuously from the first, or the arguments appear captious, as we cannot demonstrate any thing without beginning from appropriate principles, and continuing in a regular series, as far as the last. Respondents, therefore, neither think fit to define, nor consider whether the questionist defines, but when it is not evident what the proposition is, it is not easy to attack it; now, such a thing especially occurs about principles, for other things are demonstrated through these, but these cannot possibly be through others, but it is necessary to make known each thing of this kind by definition.

Those also are difficult to impugn which are very near the principle, since it is impossible to provide many arguments against them, since there are but few media between the thing itself and the principle, through which it is necessary that things subsequent to them should be demonstrated. Still, of all definitions, those are most difficult to impugn which employ such names, as at first are uncertain whether they are predicated simply or multifariously; besides which, it is unknown, whether they are predicated by the definer properly or metaphorically. For from their obscurity a person does not obtain arguments, but from his being ignorant whether such things are said metaphorically, he is without reprehension.

In short, every problem, when it is difficult of opposition, must be supposed either to stand in need of definition, or as among the number of things predicated multifariously, or metaphorically, or as not remote from principles, or from its not being first apparent to us, to which of the before-named modes this very thing which occasions the doubt is to be referred; for the mode being evident, it is clear that it will be necessary, either to define, or to divide, or to prepare middle propositions, since through these, the last are demonstrated.

In many theses also, when the definition is not well delivered, it is not easy to discourse and argue, as whether one thing is contrary to one or many things, but contraries being defined properly, we can easily collect whether there can be possibly many contraries of the same thing or not. In the same way also, as to other things which require definition, and in mathematics, some appear not easily described through a defect of definition, as that a line which laterally cuts a superficies divides similarly both a line and a space. When, however, the definition is stated, the assertion is forthwith evident, for both the spaces and the lines have a correspondent division, but this is the definition of the same sentence. In short, the first elements when definitions are laid down, as what is a line, and what a circle, are easy of demonstration, except that we cannot advance many arguments against each of these, from there not being many media, but if the definitions of the principles be not laid down, it is difficult, and perhaps altogether impossible; likewise also in those, which belong to disputations.

It ought not, therefore, to escape us, that when a thesis is opposed with difficulty, it has experienced some one of the above-mentioned (modes); since, however, it is more difficult to discuss an axiom and a proposition than a thesis, a person may doubt whether things of this kind are to be laid down or not. For if he does not admit them, but thinks fit to discuss this also, he will enjoin a greater work than what was at first laid down, but if he does admit, he will believe from things less credible. If, then, we ought not to make the problem more difficult, (that axiom) must be laid down, but if it is necessary) to syllogize through things more known, it must not be laid down; or must it not be posited by the learner, except it be more known, but must be laid down by him who exercises himself, if it only appear true? so that it is evident that the querist, and the teacher ought, not similarly to require a thing to be laid down.

Almost sufficient then, has been said as to how it is necessary to interrogate and arrange, but about reply, we must first determine what is the employment of him who answers rightly, as also of him who rightly interrogates. Now, it is the duty of the interrogator, so to induce the argument, as to make the respondent assert the most incredible things, of those which are necessary through the thesis, but of the respondent (to take care) that the impossible, or the paradoxical, do not seem to result through him, but through the thesis, since perhaps it is another fault, to place that first which ought not to be so, and not to keep what is laid down, in a proper manner.

Since the several particulars are indefinite, (which should be observed) by those who dispute for the sake of exercise and experiment—(for the same objects are not (proposed) to the teacher or the learner, and to those who contend, nor to both these, and to those who practise with each other for the sake of inquiry; for to the learner always, things which appear (true) are to be laid down, since no one attempts to teach a falsity; but of those who contend, it is necessary that the querist, should altogether seem to do something, but the respondent appear to suffer nothing; yet in dialectic associations it has not yet been distinctly explained by those who dispute, not for the sake of contest, but of experiment and inquiry, what the respondent ought to aim at, also what to concede and what not, in order to preserve the thesis well, or ill)—since then, we have nothing delivered by others, we shall endeavour to say something, ourselves.

The respondent then is required, to sustain the dispute, a probable or improbable thesis, or neither, being laid down, and which is either simply, or definitely, probable, or improbable, as to a certain person, whether himself, or another. In what way it is probable, or improbable, makes no difference, as the method of answering well, and of granting, or not granting, the question, will be the same; if then the thesis is improbable, it is necessary that the conclusion be probable, but if that, is probable, that this, should be improbable, for the querist always concludes the opposite, of the thesis. If however what is laid down, be neither improbable, nor probable, the conclusion also will be of this sort, but since he who syllogizes properly, demonstrates the proposed question, from things more probable and better known, it is evident that when what is laid down, is simply improbable, the respondent must not grant either that which does not seem simply, nor that which seems indeed, but is less apparent than the conclusion, for the thesis being improbable, the conclusion is probable, so that it is necessary that all the assumptions, should be probable, and more so, than what is proposed, if what is less known, is to be concluded, through things better known. Wherefore, except such a thing as this, is amongst the things questioned, it must not be laid down by the respondent, but if the thesis be simply probable, it is clear that the conclusion is simply improbable. Whatever then seems (true) must be laid down, and of those which do not appear (true), such as are less improbable than the conclusion, for it will appear then, that the disputation has been sufficiently well conducted. In like manner, if the thesis be neither improbable nor probable, for thus all things apparent must be admitted, and of those which do not appear, such as are more probable than the conclusion, for thus it will happen that the arguments will be more probable. If then what is laid down be simply probable or improbable, we must make a comparison with reference to those which appear simply (true), but if what is laid down, be not simply probable or improbable, but to the respondent, it must be laid down, or not, with reference to him deciding what appears, and what does not appear. If moreover the respondent defends the opinion of another, it is clear that the several particulars must be laid down and denied, looking to the conception which he forms; wherefore they who entertain strange opinions, e. g. that good and evil are the same, as Heraclitus says, do not admit that contraries are not simultaneously present with the same thing, not as if this did not seem so, to them, but because, according to Heraclitus, so it must be asserted. They also do this who receive theses from each other, since they conjecture what he who lays the thesis down will say.

It is evident then what the points are, which the respondent should direct his attention to, whether what is laid down be simply probable, or is so to a certain person; since however every question must be of necessity either probable or improbable, or neither, also must pertain either to the disputation or not, if indeed it be probable and not relevant to the argument, it must be admitted when it has been stated that it is probable; but if it be improbable and irrelevant to the argument, it must be admitted indeed, yet we must signify besides, that it does not seem probable, for the sake of avoiding silliness. If, on the other hand, it does belong to the argument, and is probable, we must say that it seems indeed, but is too near to the original proposition, and that this being admitted, the position is subverted. Still if it be relevant to the argument, but the axiom be very improbable, we must say that from this position, a conclusion indeed follows, but that what is proposed is very silly; and if it be neither improbable nor probable, if indeed it is in no respect relevant to the argument, we must grant it with no definition; but if relevant to the argument, we must signify that the original position is subverted, from this being laid down. For thus the respondent will seem to suffer nothing through himself, if the several things be laid down with foresight, and the interrogator will obtain a syllogism, when all things more probable than the conclusion are admitted by him. Nevertheless, it is clear that they do not syllogize well, who endeavour to argue from things more improbable than the conclusion, wherefore they must not be conceded by the questionists.

Likewise, we must meet those things which are obscurely and multifariously enunciated; for since it is allowed to the respondent, if he does not comprehend, to say, I do not comprehend, and if a thing be multifariously predicated, not to confess, or deny it, of necessity, it is clear that, first, if the statement be not lucid, he must not hesitate to say, that he does not understand it, since frequently, from persons interrogated, not clearly conceding, some difficulty occurs. If however a thing multifariously predicated be known, if too what is asserted be in all things true or false, it must be simply admitted or denied, or if it be partly false and partly true, we must moreover signify that it is multifariously predicated, and why it is partly false and partly true; for if this distinction is made afterwards, it will be doubtful whether he (the respondent) perceived the ambiguity at first. Now, if indeed he did not foresee the ambiguity, but laid down the position, looking to the other (signification), it must be said against him, leading to the other, that he granted without looking to this, but to the other of the things (signified); for since there are many, under the same name or sentence, a doubt easily occurs; still if the question asked be clear and simple, the answer to it must be yes or no.

Since every syllogistic proposition, is either some one of the things, from which a syllogism is formed, or (is assumed) for the sake of one of them, (for it appears manifest when it is assumed for the sake of one of them, i. e. from many things of a similar nature being interrogated, since men assume the universal, for the most part, either through induction or through similitude,)—therefore all the several particulars, must be laid down; if they be true and probable, yet we must make an attempt to urge an objection against the universal, for without an objection either real, or apparent, to impede the argument, is to be perverse. If then, where many things appear, a person does not admit the universal, having no objection, it is clear that he is perverse; moreover, if he has no argument on the contrary, (to show) that it is not true, he will seem much more perverse. Yet neither is this enough, for we have many arguments opposed to opinions, which it is difficult to solve, as that of Zeno, that nothing can be moved, nor pass through a stadium; still things opposite to these, are not on this account, to be laid down. If, then, a person does not admit when he has neither an objection nor a contrary argument, he is evidently perverse, for perversity in argument is a responsion contrary to the stated modes, destructive of syllogism.

We ought so to maintain both the thesis and the definition, that he (the respondent) may previously argue against himself; for from what the questionists subvert the position, it is clear that to these, opposition must be made.

Still we must beware of maintaining an improbable hypothesis, and it may be improbable in two ways, for both (that is improbable) from which absurdities happen to be enunciated; as if some one should say that all things are moved, or that nothing is; and also whatever things are chosen by the more depraved disposition, and which are contrary to the will; as that pleasure is the good, and that to injure, is better than to be injured. For men hate a person who makes these assertions, not as maintaining them for the sake of argument, but as what approve themselves (to him).

Whatever arguments collect the false, must be solved, by subverting that, from which the falsity arises; for the solution is not effected by subverting any thing whatever, even if what is subverted be false. For an argument may contain many falsities, as if some one assumed that he who sits writes, but that Socrates sits, since it follows from these that Socrates writes, when then, it is subverted that Socrates sits, the argument is not the more solved, though the axiom is false. Still, not on this account is the argument false, for if any one happen to be sitting indeed, but not writing, the same solution would no longer be suitable to such an one, so that this is not to be subverted, but that he who sits, writes, since not every one who sits, writes. He then, altogether solves (the argument) who subverts that, from which the falsity arises, but he understands the solution who knows that the argument depends on this, as (happens) in the case of false descriptions, since it is not sufficient to object, not even if what is subverted be false, but we must show why it is false, for thus it will be evident whether a person makes the objection from foreseeing something or not.

It is possible, notwithstanding, to prevent an argument being conclusive in four ways; either by the subversion of that whence the falsity proceeds; or by urging an objection against the questionist, (for frequently when no solution is given (by the respondent), yet the querist can proceed no further); thirdly, (by objecting) against the interrogations made, (for it may happen what we wish may not arise from the questions, because they are improperly made, yet when something is added that a conclusion may result; if, then, the querist can proceed no further, the objection would lie against the querist, but if he can, against the questions asked); the fourth and worst objection is that which relates to time, for some object such things as require more time for discussion, than the present exercise (admits).

Objections, then, as we have said, arise in four ways, but of the particulars mentioned, the first alone is a solution, the rest being certain preventions and hindrances to the conclusions.

The reprehension of an argument is not the same with respect to the argument itself, and when it forms the subject of interrogation, as often the person questioned is the cause of the argument not being well discussed, because he does not allow things from which it might be properly argued against the thesis, since it does not belong to the other alone, that the common work is properly effected. Wherefore sometimes it is necessary to argue against the speaker, and not against the thesis, when the respondent, out of contumely, makes observations contrary to the questionist; hence they cause through perverseness, the exercises to be contentious and not dialectic. Besides, since arguments of this kind are for the sake of exercise and experiment, and not of doctrine, it is evident that not only what is true, but also what is false, must be collected, neither always through what is true, but sometimes also through the false, for often when what is true is laid down, it is necessary for the disputant to subvert it, so that false assertions must be proposed. Sometimes, also, when the false is laid down, it must be subverted through falsities, since there is nothing to prevent things which have no existence, seeming to some person to be, rather than those which are true, so that when the argument subsists from things appearing (true) to him, he will be more persuaded than profited. Still, it is necessary that he who would transfer the reasoning properly, should transfer it dialectically, and not contentiously, as the geometrician (argues) geometrically, whether what is concluded be false or true; of what nature however, dialectic syllogisms are, we have shown before. Yet since he is a depraved associate, who impedes a common work, it is evident that (this is true also) in arguments, for there is something common proposed in these also, except amongst those who dispute, for the sake of contest , as it is impossible for both these to obtain the same end, for they cannot vanquish more than one. Now it is of no consequence whether this is done, through the answer or through the question, since he who interrogates contentiously, disputes badly, also he who in his answer does not admit what is apparent, nor receives what the questionist wishes to inquire. Wherefore it is clear from what we have stated, that we must not similarly reprehend an argument per se, and the questionist; since nothing hinders the argument being bad, but the questionist discoursing against the respondent in the best way possible; for against the perverse, it is not perhaps possible, to frame immediately, such syllogisms as some one would, but such as he can, frame.

Since also it is indefinite when men assume contraries, and when things (investigated) in the beginning, (for often speaking by themselves they assert contraries, and having before denied, they afterwards admit, hence when questioned they frequently allow contraries, and that which (was investigated) in the beginning,) bad arguments, must necessarily arise. The respondent however is the cause, by not admitting some things, yet admitting such as these, wherefore it is clear that we must not similarly reprehend querists and arguments.

Now there are five reprehensions of an argument per se, the first indeed, when from the questions asked nothing is concluded, neither the proposition, nor, in short, any thing; all or the greatest part of those, from which the conclusion (arises), being either false or improbable; and neither things being taken away, nor being added, nor some being taken away, but others added, the conclusion is produced. The second is, if there be not a syllogism against the thesis from such things, and in such a way, as was mentioned before. The third, if there is indeed a syllogism, from certain additions, but these should be worse than those questioned, and less probable than the conclusion. Again, if certain things are taken away, for sometimes men assume more than is necessary, so that the syllogism does not result from these being (granted); further, if from things more improbable and less credible than the conclusion, or if from things true indeed , but which require more labour to demonstrate than the problem.

Notwithstanding, we need not require the syllogisms of all problems to be alike probable and convincing; for some things investigated, are straightway by nature more easy, but others more difficult, so that he will discourse well, who argues from such as are of the greatest possible probability. Wherefore, it is evident then, there is not the same reprehension of an argument, as to what is laid down in the question, and when it is per se, for nothing prevents an argument being per se reprehensible, but commendable as to the problem; and again, vice versâ, praiseworthy per se, but reprehensible as to the problem, when it is more easy to conclude from many things probable and true. For sometimes an argument, even when conclusive, may be worse than what is inconclusive, when the one concludes from foolish things, the problem not being such, but the other requires such as are probable and true, and the argument does not consist in the things assumed. Still, it is not just to reprehend those who conclude the true through the false, for the false must of necessity always be collected through the false, yet sometimes it is possible to collect the true, even through the false, indeed it is evident from the Analytics.

When the before-named argument is a demonstration of something, if there is something else which has nothing to do with the conclusion, there will not be a syllogism about it; but if there should appear (to be one), it will be a sophism, not a demonstration. Now, a philosophema is a demonstrative syllogism; an epicheirema, a dialectic syllogism; but a sophism, a contentious syllogism; and an aporema, a dialectic syllogism of contradiction.

If moreover any thing should be demonstrated from both probable (propositions), yet not similarly probable, there is nothing to prevent what is demonstrated, being more probable than either (proposition), but if one be probable, but the other neither (probable nor improbable), or if one be probable, but the other not, if they be similarly so, (the conclusion) will also similarly be and not be, but if one is more, (the conclusion) will follow that which is more.

Now this also is an error in syllogisms, when a person demonstrates through more, what is possible through fewer things, which also are inherent in the argument; as if any one, (in order to show) that one opinion is better than another, should require it to be granted, that each thing itself subsists in the most eminent degree, but that the object of opinion is truly itself; wherefore it is more than certain other things, but what is said to be more, is referred to the more, and the opinion itself is true, which will be more accurate than certain things; yet it was required to be granted that opinion itself is true, and that each thing itself most eminently subsists, wherefore this opinion itself is more accurate. Now, what is the fault here? It is that it makes the cause latent, from which the reasoning is derived.

An argument is most clear in one way, and that the most popular, if it be so concluded, as to require no further interrogation; but in another way, which is especially said to be, when things are assumed, from which (the conclusion) necessarily results, but (the argument) concludes through conclusions; moreover, if there is any thing deficient, of what is very probable.

Again, an argument is called false in four ways; one when it appears to conclude, yet does not do so, which is called a contentious syllogism; another when it concludes, indeed, that which does not pertain to the proposed (problem), and this happens especially in arguments leading to the impossible; or it concludes pertinently to what is laid down, yet not after an appropriate method, and this is when a non-medical argument appears medical, or the non-geometrical to be geometrical, or the non-dialectic to be dialectic, whether the result be false or true. Another way, if it concludes through falsities, and of this the conclusion will be sometimes false, and sometimes true, as the false is always concluded through falsities, but it is possible that the true may be so even from things not true, as was said also before.

That the reasoning, then, is false, is rather the fault of the arguer than of the argument, and neither is it always the fault of the arguer but when it escapes him, since of many truths per se, we admit rather that, which from things especially appearing (probable), subverts something true. For such (reasoning) is a demonstration of other truths, as it is requisite that some one of the positions should not altogether be, so that there will be a demonstration of this; but if it should conclude the true through false, and very silly assertions, it will be worse than many, which collect the false, and such will be the reasoning, collecting the false. Wherefore, it is evident that the first consideration of the argument per se will be whether it concludes; next, whether (it concludes) the true or false; thirdly, from what assertions, for if from those which are false but probable, it is a logical argument, but if from what are (true) yet improbable, it is faulty. If, also, they are false, and very improbable, the argument is evidently bad, either simply, or with respect to the thing (discussed).

As to what was (investigated) in the beginning and contraries, how the questionist demands a postulate according to truth, indeed, has been told in the Analytics, but must now be discussed according to opinion.

Now, men appear to beg what was in the beginning in five ways, most evidently, indeed, and primarily, if any one begs the very thing which ought to be demonstrated; this, however, does not easily escape notice, as to the thing itself, but rather in synonyms, and wherein the name and the definition signify the same thing. Secondly, when what ought to be demonstrated particularly, any one asks for, universally, as when endeavouring to show there is one science of contraries, he demands it to be altogether granted, that there is one of opposites, for he seems to beg together with many things, that which he ought to demonstrate per se. Thirdly, if any one proposing to demonstrate the universal, begs the particular; as if when it is proposed (to be shown), that there is one science of all contraries, some one should require it to be granted, that (there is one) of certain contraries; for he also seems to beg per se separately, that which he ought to show, together with many things. Again, if a person dividing (the problem) begs the thing proposed for discussion; as if when it is necessary to show that medicine belongs to the healthy, and the diseased, he should claim each of these, to be granted separately. Or if some one should beg one of these, which are necessarily consequent to each other, as that the side of a square is incommensurate with the diameter, when he ought to show, that the diameter is incommensurate with the side.

Contraries, are begged in as many ways, as the original question; for first, if any one should demand the opposites, affirmation and negation; secondly, contraries according to opposition, as that good and evil are the same; thirdly, if a man claiming universal to be granted should require contradiction particularly, as if assuming one science of contraries, he should desire it to be granted that there is different science of the wholesome and the unwholesome, or begging this, endeavoured to assume opposition as to the universal. Again, if a man should beg the contrary to what happens necessarily through the things laid down; if also, a person should not indeed assume the opposites themselves, but should claim two such things from which there will be an opposite contradiction. Still, there is a difference between assuming contraries and a petitio principii, because the error of the one belongs to the conclusion, (for having respect to this, we say that the original question is begged,) but contraries are in the propositions, from these subsisting in a certain way, as to each other.

For the exercise and practice of such arguments as these, we must, in the first place, be accustomed to convert arguments; for thus we shall be better provided for the subject of discussion, and we shall obtain a knowledge of many arguments in a few. For to convert, is when we have changed the conclusion with the remaining interrogations, to subvert one of the data, since it is necessary, if the conclusion is not, that some one of the propositions should be subverted, as when all these are laid down, the conclusion would of necessity be. We must also consider the argument as to every thesis, both that it is so, and that it is not so, and having discovered (this), the solution must be forthwith investigated, for it will happen thus, that at the same time, we shall be exercised both in question, and answer. If also we have nobody else, (we must dispute) to ourselves; also selecting arguments about the same thesis, we must compare them side by side; for this produces a great abundance, for the purpose of constraining conviction, and affords great aid to confutation, when a person is well supplied with arguments both pro and con; since, thus, it happens that care is taken against contraries. Neither is it a small instrument to knowledge and philosophical wisdom, to be able to perceive and to have perceived the results of each hypothesis, for it remains rightly to select one of these. Now there is need for a thing of this kind of a naturally good disposition, and a good disposition is in reality, thus to be able to select properly the true, and to avoid the false; which those naturally (good) are able to perform well, since they who properly love, and hate what is adduced, judge well, what is best.

It is likewise requisite to know well, the arguments about the problems, which generally occur, and especially concerning first theses, since in these the respondents are often dissatisfied. Moreover, we ought to abound in definitions, and to have at hand those, both of the probable and of the primary, since through these, syllogisms are formed. We must endeavour also to possess those, into which the other disputations generally fall; for as in geometry it is of importance to be exercised about the elements; and in arithmetic, to be prompt in the multiplication of numbers in a regular series up to ten, also contributes greatly to the knowledge of the multiplication of the other numbers besides; so in like manner in arguments, the being prompt about principles, and tenaciously to retain propositions in the memory (are of great service). For as places laid down in the mnemonic (part of the soul) only, immediately cause us to remember them, so these also, will render a person more syllogistic, in consequence of his regarding these (propositions), defined numerically. A common proposition also, rather than an argument, should be committed to memory, since to abound with principle and hypothesis is moderately difficult.

Moreover, we must be accustomed to make one argument many, concealing as obscurely as possible, which sort of thing may be done, if a person very much recedes from the alliance of those things which are the subject of discussion. Such arguments indeed, as are especially universal, will be capable of experiencing this; as that there is not one science of many things, for thus it is in relatives, and in contraries, and in conjugates.

Besides, we ought to make universal records of arguments, even if that discussed, be particular; for thus it will be possible to make one argument many, so also in rhetorical enthymemes. Nevertheless, the disputant ought as much as possible to avoid the universal in introducing syllogisms; and it is also requisite always to observe whether the arguments are conversant with things common, for all particular are conversant with universal, and the demonstration of the universal is inherent in that which is particular, because nothing can be syllogistically concluded without universals.

We should assign the exercise of inductive arguments to a young man, but of syllogistic ones to a practised man; we should also endeavour to assume propositions from those who are skilful in syllogisms, but comparisons from the inductive, for in these each are exercised. In short, from dialectic exercise, we must endeavour to draw either a syllogism about something, or a solution, or a proposition, or an objection, or whether any one has rightly or not rightly questioned, whether himself or another, and about what each is. For from these the power (of discussion arises), and exercise is on account of power, especially in propositions and objections; since, in short, he is the dialectician, who is ready to propose and to object; but to propose is to make many things one, (since it is requisite for that to be assumed in the whole, to which the argument belongs,) but to object (is to make) one many, since a man either divides or subverts, partly admitting, and partly denying the proposition.

It is requisite still, not to dispute with every one, nor to exercise ourselves against any casual person, for it is necessary to employ bad arguments against some, since against him, who altogether tries to seem to elude us, it is just indeed, by all means, to try to draw a conclusion, yet it is not becoming. Wherefore, it is not proper readily to engage with casual persons, since depraved disputation will necessarily occur; for even those who practise themselves, cannot forbear disputing contentiously.

Likewise, also it is requisite to have arguments framed against such problems, in which being supplied with the fewest, we shall have them useful against the most; now, these are universal (arguments), and which are with more difficulty supplied from things that are obvious.