The Politics of Aristotle

by Aristotle

  Moreover you should judge by means of greater or less or like degree; for if some member of another genus exhibits such and such a character in a more marked degree, while no member of that genus exhibits that character at all, then the object in question will not exhibit it; e.g. if some form of knowledge is good in a [20] greater degree than pleasure, while no form of knowledge is good, then pleasure is not good either. Also, you should judge by a less or like degree in the same way; for so you will find it possible both to demolish and to establish a view, except that whereas both are possible by means of like degrees, by means of a less degree it is possible only to establish, not to overthrow. For if a certain capacity is good in a like [25] degree to knowledge, and a certain capacity is good, then also is knowledge; while if no capacity is good, then neither is knowledge. If, too, a certain capacity is good in a less degree than knowledge, and a certain capacity is good, then so also is knowledge; but if no capacity is good, there is no necessity that no form of knowledge either should be good. Clearly, then, it is only possible to establish a view [30] by means of a less degree.

  Not only by means of another genus can you overthrow a view, but also by means of the same, if you take the most marked instance of the character in question; e.g. if it is maintained that some form of knowledge is good, then, suppose it to be proved that prudence is not good, neither will any other kind be good, seeing that not even the kind upon which there is most general agreement is so. Moreover, you should argue from an hypothesis: you should claim that the attribute, if it [35] belongs or does not belong in one case, does so in a like degree in all, e.g. that if the soul of man is immortal, so are other souls as well, while if this one is not so, neither are the others. If, then, it is maintained that in some instance the attribute belongs, you must prove that in some instance it does not belong; for then it will follow, by [120a1] reason of the hypothesis, that it does not belong in any instance. If, on the other hand, it is maintained that it does not belong in some instance, you must prove that it does belong in some instance, for in this way it will follow that it belongs in all instances. It is clear that the maker of the hypothesis universalizes the problem, whereas it was stated in a particular form; for he claims that anyone who agrees to the particular should agree to the universal, inasmuch as he claims that if the attribute belongs in one instance, it belongs also in all instances alike [5].

  If the problem is indefinite, it is possible to overthrow it in only one way; e.g. if a man has asserted that some pleasure is good or is not good, without any further definition. For if he has asserted that some pleasure is good, you must prove universally that no pleasure is good, if the proposition in question is to be [10] demolished. And likewise, also, if he has asserted that some pleasure is not good you must prove universally that all pleasure is good: it is impossible to demolish it in any other way. For if we prove that some pleasure is not good or is good, the proposition in question is not yet demolished. It is clear, then, that it is possible to demolish an indefinite statement in one way, whereas it can be established in two ways; for whether we prove universally that all pleasure is good, or that some pleasure is good, [15] the proposition in question will have been proved. Likewise, also, supposing we are required to argue that some pleasure is not good, if we prove that no pleasure is good or that some pleasure is not good, we shall have produced an argument in both ways, both universally and in particular, to show that some pleasure is not good. If, on the [20] other hand, the thesis is definite, it will be possible to demolish it in two ways; e.g. if it is maintained that it is an attribute of some pleasure to be good, while of some it is not; for whether it is proved that all pleasure, or that no pleasure, is good, the proposition in question will have been demolished. If, however, he has stated that only one single pleasure is good, it is possible to demolish it in three ways; for by [25] proving that all pleasure, or that no pleasure, or that more than one pleasure, is good, we shall have demolished the statement in question. If the thesis is still more definite, e.g. that prudence alone of the virtues is knowledge, there are four ways of demolishing it; for if it is proved that all virtue is knowledge, or that no virtue is, or that some other virtue (e.g. justice) is, or that prudence itself is not knowledge, the [30] proposition in question will have been demolished.

  It is useful also to take a look at individual instances, in cases where some attribute has been said to belong or not to belong, as in the case of universal problems. Moreover, you should take a look among genera, dividing them by their [35] species until you come to those that are not further divisible, as has been said before; for whether the attribute is found to belong in all cases or in none, you should, after adducing many instances, claim that he should either admit your point universally, or else bring an objection showing in what case it does not hold. Moreover, in cases where it is possible to divide the accident either specifically or numerically, you should look and see whether none of them belongs, showing e.g. that time is not [120b1] moved, nor yet is a movement, by enumerating all the species of movement; for if none of these belongs to time, clearly it does not move, nor yet is a movement. Likewise, also, you can show that the soul is not a number, by dividing all numbers [5] into either odd or even; for if the soul is neither odd nor even, clearly it is not a number.

  In regard then to accident, you should set to work by means like these, and in this manner.

  BOOK IV

  1 · Next we must go on to examine questions relating to genus and property. These are elements in the questions that relate to definitions, but dialecticians seldom address their inquiries to these by themselves.

  [15] If, then, a genus is suggested for something that is, first take a look at all objects which belong to the same genus as the thing mentioned, and see whether the genus suggested is not predicated of some of them, as in the case of accident: e.g. if good is laid down as the genus of pleasure, see whether some pleasure is not good; [20] for, if so, clearly good is not the genus of pleasure; for the genus is predicated of all the members of the same species. Secondly, see whether it is predicated not in what it is, but as an accident, as white is predicated of snow, or self-moved of the soul. For snow is not just what is white, and therefore white is not the genus of snow, nor is the soul just what is moving—its motion is an accident of it, as it often is of an animal to [25] walk or to be walking. Moreover, moving does not seem to indicate what something is, but rather a state of doing or of undergoing. Likewise, also, white; for it indicates not what snow is, but a certain quality of it. So that neither of them is predicated in what it is.

  [30] Especially you should take a look at the definition of accident, and see whether it fits the genus mentioned, as (e.g.) is the case in the instances just given. For it is possible for a thing to be and not to be self-moved, and likewise, also, for it to be and not to be white. So that neither of these is the genus but an accident, since we said [35] that an accident is an attribute which can belong to a thing and also not belong.

  Moreover, see whether the genus and the species are not found in the same division, but the one is a substance while the other is a quality, or the one is a relative while the other is a quality, as (e.g.) snow and swan are each a substance, while white is not a substance but a quality, so that white is not a genus either of [121a1] snow or of swan. Again, knowledge is a relative, while good and noble are each a quality, so that good, or noble, is not the genus of knowledge. For the genera of relatives ought themselves also to be relatives, as is the case with double; for multiple, which is the genus of double, is itself also a relative. To speak generally, [5] the genus ought to fall under the same division as the species; for if the species is a substance, so too should be the genus, and if the species is a quality, so too the genus should be a quality; e.g. if white is a quality, so too should colour be. Likewise, also, in other cases.

  Again, see whether it is necessary or possible for the genus to partake of the [10] object which has been placed in the genus. Partaking is defined as ad
mitting the account of that which is partaken. Clearly, therefore, the species partake of the genera, but not the genera of the species; for the species admits the account of the genus, whereas the genus does not admit that of the species. You must look, therefore, and see whether the alleged genus partakes or can partake of the species, [15] e.g. if any one were to render anything as genus of being or of one; for then the result will be that the genus partakes of the species; for of everything that is, being and one are predicated, and therefore their account as well.

  Moreover, see if there is anything of which the alleged species is true, while the [20] genus is not, e.g. supposing being or object of knowledge were stated to be the genus of object of opinion. For object of opinion will be a predicate of what does not exist; for many things which do not exist are objects of opinion; whereas that being or object of knowledge is not predicated of what does not exist is clear. So that neither being nor object of knowledge is the genus of object of opinion; for of the objects of [25] which the species is predicated, the genus ought to be predicated as well.

  Again, see whether the object placed in the genus cannot partake of any of its species; for it is impossible that it should partake of the genus if it does not partake of any of its species, unless it is one of the species reached by the first division—these partake of the genus alone. If, therefore, motion is stated as the genus of [30] pleasure, you should look and see if pleasure is neither locomotion nor alteration, nor any of the rest of the given modes of motion; for clearly it will not partake of any of the species, and therefore not of the genus either, since what partakes of the genus must necessarily partake of one of the species as well; so that pleasure could [35] not be a species of motion, nor yet be one of the individual phenomena falling under a species of motion.10 For individuals as well partake in the genus and the species, as (e.g.) an individual man partakes of both man and animal.

  Moreover, see if the term placed in the genus has a wider denotation than the [121b1] genus, as (e.g.) object of opinion has, as compared with being; for both what is and what is not are objects of opinion, so that object of opinion could not be a species of being; for the genus is always of wider denotation than the species. Again, see if the species and its genus have an equal denotation; suppose, for instance, that of the [5] attributes which go with everything, one were to be stated as a species and the other as its genus, as for example being and one; for everything has being and one, so that neither is the genus of the other, since their denotation is equal. Likewise, also, if primitives and principles were to be placed one under the other; for a principle is a [10] primitive and a primitive a principle, so that either the two are identical or neither is the genus of the other. The elementary principle in regard to all such cases is that the genus has a wider denotation than the species and its differentia; for the differentia too has a narrower denotation than the genus.

  [15] See also whether the genus mentioned fails, or might be thought to fail, to apply to some object which is not specifically different from the thing in question; or, if your argument is constructive, whether it does so apply. For all things that are not specifically different have the same genus. If, therefore, it is proved to apply to one, then clearly it applies to all, and if it fails to apply to one, clearly it fails to apply to any; e.g. if any one who assumes that there are indivisible lines were to say that [20] the indivisible is their genus. For the aforesaid term is not the genus of divisible lines, and these do not differ as regards their species—for straight lines are never different from each other as regards their species.

  2 · Look and see, also, if there is any other genus of the given species which [25] neither embraces the given genus nor falls under it, e.g. suppose any one were to lay down that knowledge is the genus of justice. For virtue is its genus as well, and neither of these genera embraces the remaining one, so that knowledge could not be the genus of justice; for it seems that whenever one species falls under two genera, [30] the one is embraced by the other. Yet a principle of this kind gives rise to a difficulty in some cases. For some people hold that prudence is both virtue and knowledge, and that neither of its genera is embraced by the other—although certainly not everybody admits that prudence is knowledge. If, however, any one were to admit the truth of this assertion, yet it would still be thought to be necessary that the [35] genera of the same object must at any rate be subordinate either the one to the other or both to the same thing as actually is the case with virtue and knowledge. For both fall under the same genus; for each of them is a state and a disposition. You should look, therefore, and see whether neither of these things is true of the given genus; for [122a1] if the genera are subordinate neither the one to the other nor both to the same thing, then what is given could not be the genus.

  Look, also, at the genus of the given genus, and so continually at the next higher genus, and see whether all are predicated of the species, and predicated in [5] what it is; for the higher genus should be predicated of the species in what it is. If, then, there is anywhere a discrepancy, clearly what is given is not the genus. Again, see whether either the genus itself, or one of its higher genera, partakes of the species; for the higher genus does not partake of any of the lower. If, then, you are [10] overthrowing a view, follow the rule as given; if establishing one, then—suppose that what has been named as genus is admitted to belong to the species, only it is disputed whether it belongs as genus—it is enough to prove that one of its higher genera is predicated of the species in what it is. For if one of them is predicated in [15] what it is, all of them, both higher and lower than this one, if predicated at all of the species, will be predicated of it in what it is; so that what has been given as genus is also predicated in what it is. The proposition that when one genus is predicated in what it is, all the rest, if predicated at all, will be predicated in what it is, should be secured by induction. Supposing, however, that it is disputed whether the given genus belongs at all, it is not enough to prove that one of the higher genera is [20] predicated of the species in what it is: e.g. if any one has given locomotion as the genus of walking, it is not enough to prove that walking is motion in order to prove that it is locomotion, seeing that there are other forms of motion as well; but one must prove in addition that walking does not partake of any of the species of motion [25] produced by the same division as locomotion. For of necessity what partakes of the genus partakes also of one of the species produced by the first division. If, therefore, walking does not partake either of increase or decrease or of the other kinds of motion, clearly it will partake of locomotion, so that locomotion will be the genus of [30] walking.

  Again, look among the things of which the given species is predicated as genus, and see if what is given as its genus is also predicated in what it is of the very things of which the species is so predicated, and likewise if all the genera higher than this genus are so predicated as well. For if there is anywhere a discrepancy, clearly what has been given is not the genus; for had it been the genus, then both the genera [35] higher than it, and it itself, would all have been predicated in what it is of those objects of which the species too is predicated in what it is. If, then, you are overthrowing a view, it is useful to see whether the genus fails to be predicated in what it is of those things of which the species is predicated. If establishing a view, it is useful to see whether it is predicated in what it is; for if so, the result will be that [122b1] the genus and the species will be predicated of the same object in what it is, so that the same object falls under two genera; the genera must therefore of necessity be subordinate one to the other, and therefore if it is proved that the one we wish to establish as genus is not subordinate to the species, clearly the species will be [5] subordinate to it, so that it is proved that it is the genus.

  Look, also, at the accounts of the genera, and see whether they apply both to the given species and to the objects which partake of the species. For of necessity the accounts of its genera must be predicated of the species and of the obje
cts which partake of the species; if, then, there is anywhere a discrepancy, clearly what has [10] been given is not the genus.

  Again, see if he has given the differentia as the genus, e.g. immortal as the genus of God. For immortal is a differentia of living being, seeing that of living beings some are mortal and others immortal. Clearly, then, a mistake has been made; for the differentia of a thing is never its genus. And that this is true is clear; [15] for a thing’s differentia never signifies what it is, but rather some quality, as do walking and biped.

  Also, see whether he has placed the differentia inside the genus, e.g. saying that the odd is essentially a number. For odd is a differentia of number, not a species. Nor is the differentia thought to partake of the genus; for what partakes of [20] the genus is always either a species or an individual, whereas the differentia is neither a species nor an individual. Clearly, therefore, the differentia does not partake of the genus, so that odd too is no species, seeing that it does not partake of the genus.

  [25] Moreover, see whether he has placed the genus inside the species, e.g. by taking contact to be essentially continuity, or mixture essentially fusion, or, as in Plato’s definition,11 change of place to be locomotion. For there is no necessity that contact should be continuity: rather, conversely, continuity must be contact; for what is in contact is not always continuous, though what is continuous is always in [30] contact. Likewise, also, in the remaining instances; for mixture is not always a fusion (for to mix dry things does not fuse them), nor is change of place always locomotion. For walking is not thought to be locomotion; for it is mostly used of things that change one place for another involuntarily, as happens in the case of [35] inanimate things. Clearly, also, the species, in the instances given, has a wider denotation than the genus, whereas it ought to be vice versa.