by Aristotle
The so-called relative property, then, should be examined by means of the commonplace arguments relating to accident, to see whether it belongs to the one thing and not to the other; on the other hand, permanent and essential properties should be considered by the following methods.
2 · First, see whether the property has or has not been rendered correctly. Of [129b1] a rendering being incorrect or correct, one test is to see whether the terms in which the property is stated are not or are more familiar—for destructive purposes, whether they are not so, and for constructive purposes, whether they are so. Of the terms not being more familiar, one test is to see whether the property which he [5] renders is altogether more unintelligible than the subject whose property he has stated; for, if so, the property will not have been stated correctly. For we form a property for the sake of knowledge; the terms, therefore, in which it is rendered should be more familiar; for in that case it will be possible to conceive it more adequately. E.g. anyone who has stated that it is a property of fire to bear a very [10] close resemblance to the soul, uses the term soul, which is less intelligible than fire—for we know better what fire is than what soul is—, and therefore bearing a very close resemblance to the soul can not be a correctly stated property of fire. Another test is to see whether the attribution of the one to the other fails to be more familiar. For not only should the property be more familiar than its object, but also it should be something whose attribution to it is more familiar. For he who does not [15] know whether it belongs to the object, will not know either whether it belongs to it alone. Hence whichever of these results happens, the property becomes unclear. Thus (e.g.) a man who has stated that it is a property of fire to be the primary element wherein the soul is naturally found, has introduced something more [20] unintelligible than fire, viz. whether the soul is found in it, and whether it is found there primarily; and therefore to be the primary element in which the soul is naturally found will not be a correctly stated property of fire. On the other hand, for constructive purposes, see whether the terms in which the property is stated are more familiar, and whether they are more familiar in each of the aforesaid ways. For then the property will have been correctly stated in this respect; for of [25] constructive rules for correctness, some will prove correctness in a certain respect only, while others will prove it without qualification. Thus (e.g.) a man who has said that the possession of perception is a property of animal has both used more familiar terms and has rendered the property more familiar in each of the aforesaid senses; so that to possess perception will in this respect have been correctly rendered as a property of animal.
[30] Next, for destructive purposes, see whether any of the words given in the property is used in more than one way, or whether the whole expression too signifies more than one thing. For then the property will not have been correctly stated. Thus (e.g.) seeing that to perceive signifies more than one thing, viz. to possess perception, and to use perception, having perception will not be a correctly stated [130a1] property of animal. The reason why neither the word, nor the whole expression signifying the property should have more than one use is this, that an expression having more than one use makes what is said unclear, because the man who is about to attempt an argument is in doubt which of the various uses the expression has; and [5] this will not do, for the object of giving the property is to gain knowledge. Moreover, in addition to this, it is inevitable that those who render a property after this fashion should be somehow refuted whenever any one addresses his deduction to that one of the several uses which does not agree. For constructive purposes, on the other hand, see whether neither any of the terms nor the expression as a whole has more than [10] one use; for then the property will have been correctly stated in this respect. Thus (e.g.) seeing that ‘body’ does not bear several meanings, nor ‘quickest to move upwards in space’, nor yet the whole expression made by putting them together, it would be in this respect a correctly stated property of fire to be the body quickest to move upwards in space.
[15] Next, for destructive purposes, see if the term of which he renders the property is used in more than one way, and it has not been determined which of them it is whose property he is stating; for then the property will not have been correctly rendered. The reasons why this is so are quite clear from what has been said above; for the same results are bound to follow. Thus (e.g.) seeing that ‘the knowledge of [20] this’ signifies many things—for it means the possession of knowledge by it, and the use of knowledge by it, and the possession of knowledge about it, and the use of knowledge about it—no property of the knowledge of this could be rendered correctly unless it were determined which of these it is whose property is being rendered. For constructive purposes, a man should see if the term of which he is stating the property does not have many uses but is one and simple; for then the property will have been correctly stated in this respect. Thus (e.g.) seeing that man [25] is used in a single way, being a naturally civilized animal will be in this respect correctly stated as a property of man.
Next, for destructive purposes, see whether the same term has been repeated in the property. For people often do this unawares in rendering properties, just as they [30] do in their definitions as well; but a property to which this has happened will not have been correctly stated; for the repetition of it confuses the hearer. Thus inevitably it becomes unclear, and further, such people are thought to babble. Repetition of the same term is likely to happen in two ways: one is, when a man [35] repeatedly uses the same word, as would happen if any one were to render, as a property of fire, the body which is the most rarefied of bodies (for he has repeated the word ‘body’); the second is, if a man replaces words by their definitions, as would happen if any one were to render, as a property of earth, the substance which is by its nature most easily of all bodies borne downwards in space, and were then to [130b1] substitute ‘substances of such and such a kind’ for ‘bodies’ (for a body and a substance of such and such a kind are one and the same thing). For he will have repeated the word ‘substance’. Hence neither of the properties will be correctly [5] stated. For constructive purposes, on the other hand, see whether he avoids ever repeating the same word; for then the property will in this respect have been correctly rendered. Thus (e.g.) seeing that he who has stated animal capable of acquiring knowledge as a property of man has not used the same term several times, the property will in this respect have been correctly rendered of man. [10]
Next, for destructive purposes, see whether he has rendered in the property any term that belongs to everything. For one which does not distinguish its subject from other things is useless, and it is the business of what is stated in properties, as also of what is stated in definitions, to distinguish. Hence the property will not have been correctly rendered. Thus (e.g.) a man who has stated that it is a property of [15] knowledge to be belief incontrovertible by argument, because it is one, has used in the property a term of that kind, viz. one, which belongs to everything; and therefore the property of knowledge could not have been correctly stated. For constructive purposes, on the other hand, see whether he has avoided all terms that are common to everything and used a term that distinguishes the subject from something; for then the property will in this respect have been correctly stated. Thus (e.g.) inasmuch as he who has said that it is a property of a living creature to have a [20] soul has used no term that is common to everything, it will in this respect have been correctly stated to be a property of a living creature to have a soul.
Next, for destructive purposes see whether he renders more than one property of the same thing, without a definite proviso that he is stating more than one; for then the property will not have been correctly stated. For just as in the case of [25] definitions too there should be no further addition beside the account which shows the substance of the thing, so too in the case of properties nothing further should be rendered beside the account that makes what is stated a property; for such an addition is made to no purpose. Thus (e.g.) a ma
n who has said that it is a property of fire to be the most rarefied and lightest body has rendered more than one [30] property (for each term is true of fire alone); and so it could not be a correctly stated property of fire to be the most rarefied and lightest body. On the other hand, for constructive purposes, see whether he has avoided giving more than one property of the same thing, and has given one only; for then the property will in this respect [35] have been correctly stated. Thus (e.g.) a man who has said that it is a property of a liquid to be a body adaptable to every shape has given a single property and not several, and so the property of liquid will in this respect have been correctly stated.
3 · Next, for destructive purposes, see whether he has used in addition either the actual subject whose property he is rendering, or any of its species; for then the [131a1] property will not have been correctly stated. For the object of giving the property is to gain knowledge: now the subject itself is just as unintelligible as itself, while any one of its species is posterior to it, and so is no more familiar. Accordingly it is impossible to gain any knowledge by the use of these terms. Thus (e.g.) any one who [5] has said that it is a property of animal to be the substance to which man belongs as a species has employed one of its species, and therefore the property will not have been correctly stated. For constructive purposes, on the other hand, see whether he avoids introducing either the subject itself or any of its species; for then the property will in this respect have been correctly stated. Thus (e.g.) a man who has stated that it is a property of a living creature to be compounded of soul and body has used in [10] addition neither the subject itself nor any of its species, and therefore in this respect the property of a living creature will have been correctly rendered.
You should inquire in the same way also in the case of other terms that do or do not make the subject more familiar: thus, for destructive purposes, see whether he has used in addition anything either opposite to the subject or, in general, anything [15] simultaneous by nature with it or posterior to it; for then the property will not have been correctly stated. For an opposite is simultaneous by nature with its opposite, and what is simultaneous by nature or is posterior to it does not make its subject more familiar. Thus (e.g.) any one who has said that it is a property of good to be the most direct opposite of evil, has used in addition the opposite of good, and so the [20] property of good could not have been correctly rendered. For constructive purposes, on the other hand, see whether he has used in addition neither anything opposite to, nor, in general, simultaneous by nature with the subject, nor posterior to it; for then the property will in this respect have been correctly rendered. Thus (e.g.) a man who has stated that it is a property of knowledge to be the most convincing belief has not used in addition anything either opposite to, or simultaneous by nature with, or [25] posterior to, the subject; and so the property of knowledge will in this respect have been correctly stated.
Next, for destructive purposes, see whether he has rendered as property something that does not always21 follow the subject but sometimes ceases to be its property; for then the property will not have been correctly described. For there is no necessity either that the name of the subject must also be true of anything to [30] which we find it belonging; or that the name of the subject will be untrue of anything to which it is found not to belong. Hence the property will not have been correctly stated. Moreover, in addition to this, even after he has rendered the property it will not be clear whether it belongs, seeing that it is the kind of attribute that may fail; and so the property will not be clear. Thus (e.g.) a man who has stated [35] that it is a property of animal sometimes to move and sometimes to stand still has given as a property the kind of thing which sometimes is not a property, and so the property will not have been correctly stated. For constructive purposes, on the other hand, see whether he has rendered something that of necessity must always be a property; for then the property will have been in this respect correctly stated. Thus [131b1] (e.g.) a man who has stated that it is a property of virtue to be what makes its possessor good has rendered as property something that always follows, and so the property of virtue will in this respect have been correctly rendered.
Next, for destructive purposes, see whether in rendering a present property he [5] has omitted to make a definite proviso that it is a present property which he is rendering; for else the property will not have been correctly stated. For in the first place, any unusual procedure always needs a definite proviso; and for the most part everybody is accustomed to render as property some attribute that always follows. In the second place, a man who omits to provide definitely whether it was the [10] present property which he intended to state, is obscure; and one should not give any occasion for adverse criticism. Thus (e.g.) a man who has stated it as the property of a particular man to be sitting with a particular man, states the present property, and so he cannot have rendered the property correctly, seeing that he has described it without any definite proviso. For constructive purposes, on the other hand, see whether, in giving a present property, he has, in stating it, made a definite proviso [15] that it is the present property that he is stating; for then the property will in this respect have been correctly stated. Thus (e.g.) a man who has said that it is the property of a particular man to be walking now, has made this distinction in his statement, and so the property will have been correctly stated.
Next, for destructive purposes, see whether he has rendered a property of the kind whose presence is not obvious except by perception; for then the property will [20] not have been correctly stated. For every perceptible attribute, once it passes beyond the range of perception, becomes obscure. For it is not clear whether it still belongs, because it is known only by perception. This will be true in the case of any attributes that do not always and necessarily follow. Thus (e.g.) any one who has stated that it is a property of the sun to be the brightest star that moves over the [25] earth, has used in the property something, viz. moving over the earth, of a kind which is known by perception; and so the sun’s property will not have been correctly rendered; for it will be obscure, whenever the sun sets, whether it continues to move over the earth, because perception then fails us. For constructive purposes, on the [30] other hand, see whether he has rendered the property of a kind that is not obvious by perception, or, if it is perceptible, must clearly belong of necessity; for then the property will in this respect have been correctly stated. Thus (e.g.) a man who has stated that it is a property of a surface to be the primary thing that is coloured, has used in addition something perceptible, being coloured, but something which [35] evidently always belongs, and so the property of surface will in this respect have been correctly rendered.
Next, for destructive purposes, see whether he has rendered the definition as a property; for then the property will not have been correctly stated; for the property [132a1] of a thing ought not to show its essence. Thus (e.g.) a man who has said that it is a property of man to be a terrestrial two-footed animal has rendered as a property of man something that signifies his essence, and so the property of man will not have been correctly rendered. For constructive purposes, on the other hand, see whether [5] the property which he has rendered is predicated convertibly without, however, signifying its essence; for then the property will in this respect have been correctly rendered. Thus (e.g.) he who has stated that it is a property of man to be a naturally civilized animal has rendered the property so as to be predicated convertibly without, however, showing its essence, and so the property of man will in this respect have been correctly rendered.
[10] Next, for destructive purposes, see whether he has rendered the property without having placed it in what it is. For of properties, as also of definitions, the first term to be rendered should be the genus, and then the rest of it should be appended immediately afterwards, and should distinguish its subject from other things. Hence a property which is not stated in this way will not have been correctly [15] rendered. Thus (e.g.) a man who has said that it is a pr
operty of a living creature to have a soul has not placed living creature within what it is and so the property of a living creature will not have been correctly stated. For constructive purposes, on the other hand, see whether a man first places within what it is the subject whose property he is rendering, and then appends the rest; for then the property will in this respect have been correctly rendered. Thus (e.g.) he who has stated that it is a [20] property of man to be an animal capable of receiving knowledge, has rendered the property after placing the subject within what it is, and so the property of man will in this respect have been correctly rendered.
4 · The inquiry, then, whether the property has been correctly rendered or no, should be made by these means. The question, on the other hand, whether what is stated is or is not a property at all, you should examine from the following points [25] of view. For the commonplace rules which establish absolutely that the property is correctly stated will be the same as those that constitute it a property at all; accordingly they will be described in the course of them.
Firstly, then, for destructive purposes, take a look at each subject of which he has rendered the property, and see (e.g.) if it fails to belong to any of them at all, or [30] to be true of them in respect of that character of which he has rendered the property; for then what is stated to be a property will not be a property. Thus, for example, inasmuch as it is not true of the geometrician that he cannot be deceived by an argument (for a geometrician is deceived when his figure is misdrawn), it will not be a property of the man of science that he is not deceived by an argument. For constructive purposes, on the other hand, see whether the property rendered be true [35] of every instance, and true in that particular respect; for then what is stated not to be a property will be a property. Thus, for example, inasmuch as being an animal capable of receiving knowledge is true of every man, and true of him qua man, it [132b1] will be a property of man to be an animal capable of receiving knowledge. [This commonplace rule means—for destructive purposes, see if the account fails to be true of that of which the name is true; and if the name fails to be true of that of which the account is true; for constructive purposes, on the other hand, see if the [5] account too is predicated of that of which the name is predicated, and if the name too is predicated of that of which the account is predicated.]22