LESSON 3

The Same Science Considers Unity and Plurality and All Opposites. The Method of Treating These

Chapter 2: 1004a 9-1004a 34

             306. Now since it is the office of a single science to study opposites, and plurality is the opposite of unity, it is also the office of a single science to study negation and privation, because in both cases we are studying the unity of which there is negation or privation. And this (negation or privation) is what is stated either absolutely because an attribute is not present in a thing or (not absolutely) because it is not present in some determinate class. Therefore this difference is present in unity over and above what is implied in negation; for negation is the absence of the thing in question. But in the case of privation there is an underlying subject of which the privation is predicated.

             307. But plurality is the opposite of unity. Hence the opposites of the above-mentioned concepts, otherness, unlikeness, and inequality, and any others which are referred to plurality or unity, must come within the scope of the science mentioned above. And contrariety is one of these; for contrariety is a kind of difference, and difference is a kind of otherness.

             308. Hence, since the term one is used in many senses, the terms designating the foregoing opposites will also be used in many senses. Yet it is the business of one science to know them all. For even if some term is used in many senses, it does not therefore follow that it belongs to another science. Hence if terms are not used with one meaning, and their concepts are not referred to one thing, then it is the office of a different science to study them. But since all things are referred to some primary thing, as all things which are one are referred to a primary one, the same thing must hold true of sameness, otherness, and the contraries. It is necessary, then to distinguish all the senses in which each term is used and then refer them back to the primary thing signified in each of the predicates in question to see how each is related to it. For one thing is given a particular predicate because it possesses it, another because it produces it, and others in other ways.

             309. Hence it is evident, as has been stated in our problems, that it is the office of a single science to give an account of these predicates as well as of substance; and this was one of the problems (181:C 346; 202:C 393).

COMMENTARY

             564. Here he shows that it is the office of this science to consider opposites; and in regard to this he does two things. First (306:C 564), he shows that it is the office of this science to consider privation and negation; and second (307:C 567), to consider contraries ("But plurality").

             He accordingly says (306) that, since it pertains to one science to consider opposites (for example, it belongs to medicine to consider health and sickness, and to grammar to consider agreement and disagreement), and since plurality is the opposite of unity, the study of privation and negation must belong to that science which deals with unity and plurality. For the consideration "of both" involves unity; that is, the study of unity, whose concept entails negation and privation, depends on both of these. For, as has been said above (302:C 553), what is one is an undivided being, and division relates to plurality, which is the opposite of unity. Hence the study of negation and privation belongs to that science whose business it is to consider unity.

             565. Now there are two kinds of negation: simple negation, by which one thing is said absolutely not to be present in something else, and negation in a genus, by which something is denied of something else, not absolutely, but within the limits of some determinate genus. For example, not everything that does not have sight is said absolutely to be blind, but something within the genus of an animal which is naturally fitted to have sight. And this difference is present in unity over and above "what is implied in negation"; i.e., it is something by which it differs from negation, because negation expresses only the absence of something, namely, what it removes, without stating a determinate subject. Hence simple negation can be verified both of a non-being, which is not naturally fitted to have something affirmed of it, and of a being which is naturally fitted to have something affirmed of it and does not. For unseeing can be predicated both of a chimera and of a stone and of a man. But in the case of privation there is a determinate nature or substance of which the privation is predicated; for not everything that does not have sight can be said to be blind, but only that which is naturally fitted to have sight. Thus since the negation which is included in the concept of unity is a negation in a subject (otherwise a non-being could be called one), it is evident that unity differs from simple negation and rather resembles the nature of privation, as is stated below in Book X (865:C 2069) of this work.

             566. But it must be noted that, although unity includes an implied privation, it must not be said to include the privation of plurality; for, since a privation is subsequent in nature to the thing of which it is the privation, it would follow that unity would be subsequent in nature to plurality. And it would also follow that plurality would be given in the definition of unity; for a privation can be defined only by its opposite. For example, if someone were to ask what blindness is, we would answer that it is the privation of sight. Hence, since unity is given in the definition of plurality (for plurality is an aggregate of units), it would follow that there would be circularity in definitions. Hence it must be said that unity includes the privation of division, although not the kind of division that belongs to quantity; for this kind of division is limited to one particular class of being and cannot be included in the definition of unity. But the unity which is interchangeable with being implies the privation of formal division, which comes about through opposites, and whose primary root is the opposition between affirmation and negation. For those things are divided from each other which are of such a kind that one is not the other. Therefore being itself is understood first, and then non-being, and then division, and then the kind of unity which is the privation of division, and then plurality, whose concept includes the notion of division just as the concept of unity includes the notion of undividedness. However, some of the things that have been distinguished in the foregoing way can be said to include the notion of plurality only if the notion of unity is first attributed to each of the things distinguished.

             567. But plurality (307).

             Here he shows that it is the business of the philosopher to consider contraries, or opposites; for plurality is the opposite of unity, as has been said (306:C 564), and it is the office of one science to consider opposites. Hence, since this science considers unity, sameness, likeness and equality, it must also consider their opposites, plurality, otherness or diversity, unlikeness and inequality, and all other attributes which are reduced to these or even to unity and plurality. And contrariety is one of these; for contrariety is a kind of difference, namely, of things differing in the same genus. But difference is a kind of otherness or diversity, as is said in Book X (840:C 2017). Therefore contrariety belongs to the consideration of this science.

             568. Hence, since (308).

             Then he deals with the method by which the philosopher ought to establish these things. He says that, since all of the above-mentioned opposites are derived from unity, and the term one is used in many senses, all of the terms designating these must also be used in many senses, i.e., same, other, and so on. Yet even though all of these are used in many senses, it is still the work of one science, philosophy, to know the things signified by each of these terms. For if some term is used in many senses, it does not therefore follow that it belongs to another or different science. For if the different things signified are not referred to "with one meaning," or according to one concept, i.e., univocally, or are not referred to one thing in different ways, as in the case of analogous things, then it follows that it is the office of another, i.e., of a different, science, to consider them; or at least it is the office of one science accidentally, just as astronomy considers a star in the heavens, i.e., the dog star, and natural science considers a dog-fish and a dog.--But all of these are referred to one starting point. For things signified by the term one, even though diverse, are referred back to a primary thing signified as one; and we must also speak in the same way of the terms same, other, contrary, and others of this kind. Regarding each of these terms, then, the philosopher should do two things. First, he should distinguish the many senses in which each may be used; and second, he should determine regarding "each of the predicates," i.e., each of the names predicated of many things, to what primary thing it is referred. For example, he should state what the first thing signified by the term same or other is, and how all the rest are referred to it; one inasmuch as it possesses it, another inasmuch as it produces it, or in other ways of this kind.

             569. Hence it is evident (309).

             He draws his conclusion from what has been said, namely, that it belongs to this science to reason about these common predicates and about substance; and this was one of the problems investigated in the questions treated dialectically in Book III (181:C 346; 202:C 393).