Commentary on Aristotle's Metaphysics

 PROLOGUE

 BOOK I

 LESSON 1

 LESSON 2

 LESSON 3

 LESSON 4

 LESSON 5

 LESSON 6

 LESSON 7

 LESSON 8

 LESSON 9

 LESSON 10

 LESSON 11

 LESSON 12

 LESSON 13

 LESSON 14

 LESSON 15

 LESSON 16

 LESSON 17

 BOOK II

 LESSON 1

 LESSON 2

 LESSON 3

 LESSON 4

 LESSON 5

 BOOK III

 LESSON 1

 LESSON 2

 LESSON 3

 LESSON 4

 LESSON 5

 LESSON 6

 LESSON 7

 LESSON 8

 LESSON 9

 LESSON 10

 LESSON 11

 LESSON 12

 LESSON 13

 LESSON 14

 LESSON 15

 BOOK IV

 LESSON 1

 LESSON 2

 LESSON 3

 LESSON 4

 LESSON 5

 LESSON 6

 LESSON 7

 LESSON 8

 LESSON 9

 LESSON 10

 LESSON 11

 LESSON 12

 LESSON 13

 LESSON 14

 LESSON 15

 LESSON 16

 LESSON 17

 BOOK V

 LESSON 1

 LESSON 2

 LESSON 3

 LESSON 4

 LESSON 5

 LESSON 6

 LESSON 7

 LESSON 8

 LESSON 9

 LESSON 10

 LESSON 11

 LESSON 12

 LESSON 13

 LESSON 14

 LESSON 15

 LESSON 16

 LESSON 17

 LESSON 18

 LESSON 19

 LESSON 20

 LESSON 21

 LESSON 22

 BOOK VI

 LESSON 1

 LESSON 2

 LESSON 3

 LESSON 4

 LESSON 1

 LESSON 2

 LESSON 3

 LESSON 4

 LESSON 5

 LESSON 6

 LESSON 7

 LESSON 8

 LESSON 9

 LESSON 10

 LESSON 11

 LESSON 12

 LESSON 13

 LESSON 14

 LESSON 15

 LESSON 16

 LESSON 17

 BOOK VIII

 LESSON 1

 LESSON 2

 LESSON 3

 LESSON 4

 LESSON 5

 LESSON 1

 LESSON 2

 LESSON 3

 LESSON 4

 LESSON 5

 LESSON 6

 LESSON 7

 LESSON 8

 LESSON 9

 LESSON 10

 LESSON 11

 BOOK X

 LESSON 1

 LESSON 2

 LESSON 3

 LESSON 4

 LESSON 5

 LESSON 6

 LESSON 7

 LESSON 8

 LESSON 9

 LESSON 10

 LESSON 11

 LESSON 12

 Book XI

 LESSON 1

 LESSON 2

 LESSON 3

 LESSON 4

 LESSON 5

 LESSON 6

 LESSON 7

 LESSON 8

 LESSON 9

 LESSON 10

 LESSON 11

 LESSON 12

 LESSON 13

 BOOK XII

 LESSON 1

 LESSON 2

 LESSON 3

 LESSON 4

 LESSON 5

 LESSON 6

 LESSON 7

 LESSON 8

 LESSON 9

 LESSON 10

 LESSON 11

 LESSON 12

 Footnotes

LESSON 8

Are Genera Principles of Things? And If So, Does This Apply to The Most Universal Genera or to Those Nearest to Individuals?

Chapter 3: 998a 20-999a 23

             220. Concerning the principles of things there is the problem whether genera must be regarded as the elements and principles of things, or rather the first things of which each thing is composed inasmuch as they are intrinsic.

             221. Just as the elements and principles of a word seem to be those things of which all words are first composed, but not word in common. And just as we say that the elements of diagrams are those things whose demonstrations are found in the demonstrations of others, either of all or of most of them.

             222. Furthermore, those who say that the elements of bodies are many, and those who say that they are one, call the things of which bodies are composed and constituted their principles, as Empedocles says that fire and water and those things which are included with these are the elements from which existing things derive their being; but he does not speak of them as the genera of existing things.

             223. And again if anyone wished to speculate about the nature of other things, in finding out in regard to each (a bed, for example) of what parts it is made and how it is put together, he will come to know its nature. And according to these arguments genera are not the principles of existing things.

             224. But if we know each thing through definitions, and genera are the principles of definitions, genera must be the principles of the things defined.

             225. And if in order to acquire scientific knowledge of existing things it is necessary to acquire scientific knowledge of their species, according to which they are said to be beings, then genera are the principles of species.

             226. Moreover, some of those who say that the elements of existing things are the one or being or the great and small, seem to use these as genera.

             227. But it is not possible to speak of principles in both ways; for the meaning of substance is one. Therefore a definition by means of genera will differ from one which gives the intrinsic constituents.

             228. Again, if genera are the principles of things in the fullest sense, there is the question whether the first genera must be thought to be principles, or those which are lowest and are predicated of individual things. For this also raises a problem.

             229. For if universals are the principles of things to a greater degree, evidently these must be the highest genera, because it is most properly these which are predicated of all existing things. Therefore there will be as many principles of existing things as there are first genera. Hence being and unity will be principles and substances, for it is these especially which are predicated of all existing things. It is impossible, however, that unity or being should be a single genus of existing things; for it is necessary both that the differences of each genus exist and that each be one. But it is impossible either that species be predicated of the differences of their own genera, or that a genus be so predicated independently of its species. If, then, unity or being is a genus, no difference will be one and a being. But if unity and being are not genera, neither will they be principles, supposing that genera are principles.

             230. Further, those things which are intermediate and are taken along with differences will be genera down to individuals. But some seem to be such, whereas others do not. Again, differences are principles to a greater degree than genera; and if they are principles, principles will be infinite in number, so to speak. And [this will appear] in another way also if one holds that the first genus is a principle.

             231. But, on the other hand, if unity is a specific principle to a greater degree, and unity is indivisible, and everything indivisible is such either in quantity or in species, and what is indivisible in species is prior, and genera are divisible into species, then it will be rather the lowest predicate which is one. For man is not the genus of particular men.

             232. Further, in the case of those things to which prior and subsequent apply, it is not possible in their case that there should be something which exists apart from them. For example, if the number two is the first of numbers, there will not be any number apart from the species of numbers; nor, likewise, any figure apart from the species of figures. But if the genera of these things do not [exist apart from the species], then in the case of other things the teaching will be that there are genera apart from the species; for of these things there seem especially to be genera. But among individual things one is not prior and another subsequent.

             233. Further, where one thing is better and another worse, that which is better is always prior; so that there will be no genus of these things. From these considerations, then, it seems that it is the terms predicated of individuals, rather than genera, which are principles.

             234. But again it is not easy to state how one must conceive these to be the principles of things. For a principle or cause must be distinct from the things of which it is the principle or cause, and must be able to exist apart from them. But why should one think that anything such as this exists apart from singular things, except that it is predicated universally and of all things? But if this is the reason, then the more universal things are, the more they must be held to be principles. Hence the first genera will be principles of things.

COMMENTARY

             423. Having debated the questions which were raised about substances, the Philosopher now treats dialectically the questions which were raised about principles. This is divided into two parts. In the first (220:C 423) he discusses the questions which asked what the principles of things are; and in the second (245:C 456), the questions which asked what kind of things the principles are ("Again, there is the problem").

             In the first part of this division he discusses two questions: first, whether universals are the principles of things; and second (235:C 443), whether any principles are separate from matter ("But there is a problem").

             In regard to the first he discusses two questions, of which the first is whether genera are the principles of things. The second (228:C 431) asks which genera these are, whether the first genera or the others ("Again, if genera").

             In regard to the first he does two things: first, he raises the question; and second (221:C 424), he treats it dialectically ("Just as the elements").

             The first question (220) has to do with the principles of things: whether it is necessary to accept or believe that those genera which are predicated of many things are the elements and principles of things, or rather that those parts of which every single thing is composed must be called the elements and principles of things. But he adds two conditions, one of which is "inasmuch as they are intrinsic," which is given in order to distinguish these parts from a contrary and a privation. For white is said to come from black, or the non-white, although these are not intrinsic to white. Hence they are not its elements. The other condition is what he calls "the first things," which is given in order to distinguish them from secondary components. For the bodies of animals are composed of flesh and nerves, which exist within the animal; yet these are not called the elements of animals, because they are not the first things of which an animal is composed, but rather fire, air, water and earth, from which flesh and nerves derive their being.

             424. Just as the elements (221).

             Here he treats this question dialectically; and in regard to this he does three things. First, he shows that the first things of which anything is composed are its principles and elements. Second (224:C 427), he argues the opposite side of the question ("But if we know"). Third (227:C 430), he rejects one answer by which it could be said that both of these [i.e., genera and constituent parts] are the principles and elements of things ("But it is not").

             In regard to the first he gives three arguments. The first of these proceeds from natural phenomena, in which he makes his thesis evident by two examples. The first example which he gives if that of a word, whose principle and element is not said to be the common term word but rather the first constituents of which all words are composed, which are called letters. He gives as a second example, diagrams, i.e., the demonstrative descriptions of geometrical figures. For the elements of these diagrams are not said to be the common term diagram but rather those theorems whose demonstrations are found in the demonstrations of other geometrical theorems, either of all or of most of them, because the other demonstrations proceed from the supposition of the first demonstrations. Hence the book of Euclid is called The Book of Elements, because the first theorems of geometry, from which the other demonstrations proceed, are demonstrated therein.

             425. Furthermore, those who (222).

             Here he gives the second argument, which also employs certain examples drawn from nature. He says that those who hold that the elements of bodies are either one or many, say that the principles and elements of bodies are those things of which bodies are composed and made up as intrinsic constituents. Thus Empedocles says that the elements of natural bodies are fire and water and other things of this kind, which along with these he calls the elements of things; and natural bodies are constituted of these first things inasmuch as they are intrinsic. Moreover, they [i.e., the philosophers of nature] held that in addition to these two principles there are four others--air, earth, strife and friendship--as was stated in Book I (50:C 104). But neither Empedocles nor the other philosophers of nature said that the genera of things are the principles and elements of these natural bodies.

             426. And again if anyone (223).

             Here he gives the third argument, which involves things made by art. He says that if someone wished to "speculate about their nature," i.e., about the definition which indicates the essence of other bodies than natural ones, namely, of bodies made by human art, for example, if one wished to know a bed, it would be necessary to consider of what parts it is made and how they are put together; and in this way he would know the nature of a bed. And after this he concludes that genera are not the principles of existing things.

             427. But if we know (224).

             Here he argues the other side of the question. He gives three arguments, the first of which is as follows. Each thing is known through its definition. Therefore, if a principle of being is the same as a principle of knowing, it seems that anything which is a principle of definition is also a principle of the thing defined. But genera are principles of definitions, because definitions are first composed of them. Hence genera are the principles of the things defined.

             428. And if in order to (225).

             Here he gives the second argument, which runs thus. Scientific knowledge of each thing is acquired by knowing the species from which it gets its being, for Socrates can be known only by understanding that he is man. But genera are principles of species, because the species of things are composed of genera and differences. Therefore genera are the principles of existing things.

             429. Moreover, some of those (226).

             Here he gives a third argument, which is based on the authority of the Platonists, who held that the one and being are the principles of things, and also the great and small, which are used as genera. Therefore genera are the principles of things.

             430. But it is not possible (227).

             Here he excludes one answer which would say that both of these are principles. He says that it is impossible to say that both of these are "principles," i.e., both the elements, or the parts of which something is composed, and genera. He proves this by the following argument. Of each thing there is one definite concept which exposes its substance, just as there is also one substance of each thing. But the definitive concept which involves genera is not the same as the one which involves the parts of which a thing is composed. Hence it cannot be true that each definition indicates a thing's substance. But the definitive concept which indicates a thing's substance cannot be taken from its principles. Therefore it is impossible that both genera and the parts of which things are composed should be simultaneously the principles of things.

             431. Again, if genera (228).

             Then he treats the second question dialectically. First, he raises the question; and second (229:C 432), he brings up arguments relative to this question ("For if universals").

             Accordingly, he says that if we hold that genera are the principles of things in the fullest sense, which of these genera should be considered to be the principles of things to a greater degree? Must we consider those "genera" which are first in number, namely, the most common, or also the lowest genera, which are proximately predicated of the individual, i.e., the lowest species. For this is open to question, as is clear from what follows.

             432. For if universals (229).

             Here he argues about the question which was proposed; and in regard to this he does three things. First, he introduces arguments to show that the first genera cannot be principles. Second (231:C 436), he introduces arguments to show that the last species should rather be called the principles of things ("But, on the other hand"). Third (234:C 441), he debates the proposed question ("But again it is").

             In regard to the first (229) he gives three arguments, of which the first runs thus: if genera are principles to the extent that they are more universal, then those which are most universal, i.e., those which are predicated of all things, must be the first genera and the principles of things in the highest degree. Hence there will be as many principles of things as there are most common genera of this kind. But the most common of all genera are unity and being, which are predicated of all things. Therefore unity and being will be the principles and substances of all things. But this is impossible, because unity and being cannot be genera of all things. For, since unity and being are most universal, if they were principles of genera, it would follow that genera would not be the principles of things. Hence the position which maintains that the most common genera are principles is an impossible one, because from it there follows the opposite of what was held, namely, that genera are not principles.

             433. That being and unity cannot be genera he proves by this argument: since a difference added to a genus constitutes a species, a species cannot be predicated of a difference without a genus, or a genus without a species. That it is impossible to predicate a species of a difference is clear for two reasons. First, because a difference applies to more things than a species, as Porphyry says; and second, because, since a difference is given in the definition of a species, a species can be predicated essentially of a difference only if a difference is understood to be the subject of a species, as number is the subject of evenness in whose definition it is given. This, however, is not the case; but a difference is rather a formal principle of a species. Therefore a species cannot be predicated of a difference except, perhaps, in an incidental way. Similarly too neither can a genus, taken in itself, be predicated of a difference by essential predication. For a genus is not given in the definition of a difference, because a difference does not share in a genus, as is stated in Book IV of The Topics; nor again is a difference given in the definition of a genus. Therefore a genus is not predicated essentially of a difference in any way. Yet it is predicated of that which "has a difference," i.e., of a species, which actually contains a difference. Hence he says that a species is not predicated of the proper differences of a genus, nor is a genus independently of its species, because a genus is predicated of its differences inasmuch as they inhere in a species. But no difference can be conceived of which unity and being are not predicated, because any difference of any genus is a one and a being, otherwise it could not constitute any one species of being. It is impossible, then, that unity and being should be genera.

             434. Further, those things (230).

             Then he gives the second argument, which runs thus: if genera are called principles because they are common and predicated of many things, then for a like reason all those things which are principles because they are common and predicated of many will have to be genera. But all things which are intermediate between the first genera and individuals, namely, those which are considered together with some differences, are common predicates of many things. Hence they are both principles and genera. But this is evidently false. For some of them are genera, as subaltern species, whereas others are not, as the lowest species. It is not true, then, that the first or common genera are the principles of things.

             435. Further, if the first genera are principles, because they are the principles by which we know species, then differences will be principles to a greater degree, because differences are the formal principles of species; and form or actuality is chiefly the principle of knowing. But it is unfitting that differences should be the principles of things, because in that case there would be an infinite number of principles, so to speak; for the differences of things are infinite, so to speak; not infinite in reality but to us. That they are infinite in number is revealed in two ways: in one way if we consider the multitude of differences in themselves; in another way if we consider the first genus as a first principle, for evidently innumerable differences are contained under it. The first genera, then, are not the principles of things.

             436. But on the other hand (231).

             Then he shows that the lowest species are principles to a greater degree than genera. He gives three arguments, of which the first runs thus: according to the Platonists it is the one which seems to have "the nature," or character, of a principle to the greatest degree. Indeed, unity has the character of indivisibility, because a one is merely an undivided being. But a thing is indivisible in two ways, namely, in quantity and in species: in quantity, as the point and unit, and this is a sort of indivisibility opposed to the division of quantity; and in species, as what is not divided into many species. But of these two types of indivisibility the first and more important one is indivisibility in species, just as the species of a thing is prior to its quantity. Therefore that which is indivisible in species is more of a principle because it is indivisible in quantity. And in the division of quantity the genus seems to be more indivisible, because there is one genus of many species; but in the division of species one species is more indivisible. Hence the last term which is predicated of many, which is not a genus of many species, namely, the lowest species, is one to a greater degree in species than a genus; for example, man or any other lowest species is not the genus of particular men. Therefore a species is a principle to a greater degree than a genus.

             437. Further, in the case of (232).

             Then he gives the second argument, which is based on a certain position of Plato; for at one time Plato held that there is some one thing which is predicated of many things without priority and posteriority, and that this is a separate unity, as man is separate from all men; and at another time he held that there is some one thing which is predicated of many things according to priority and posteriority, and that this is not a separate unity. This is what Aristotle means when he says "in the case of those things to which prior and subsequent apply," i.e., that when one of the things of which a common term is predicated is prior to another, it is impossible in such cases that there should be anything separate from the many things of which this common term is predicated. For example, if numbers stand in such a sequence that two is the first species of number, no separate Idea of number will be found to exist apart from all species of numbers. And on the same grounds no separate figure will be found to exist apart from all species of figures.

             438. The reason for this can be that a common attribute is held to be separate so as to be some first entity in which all other things participate. If, then, this first entity is a one applicable to many in which all other things participate, it is not necessary to hold that there is some separate entity in which all things participate. But all genera seem to be things of this kind, because all types of genera are found to differ insofar as they are more or less perfect, and thus insofar as they are prior and subsequent in nature. Hence, if in those cases in which one thing is prior to another it is impossible to regard anything common as a separate entity, on the supposition that there is a genus apart from species, then "in the case of other things the teaching" will [differ], i.e., there will be another doctrine and rule concerning them, and the foregoing rule will not apply to them. But considering the individuals of one species, it is evident that one of these is not prior and another subsequent in nature but only in time. And thus according to Plato's teaching a species is separate. Since, then, these common things are principles inasmuch as they are separate, it follows that a species is a principle to a greater degree than a genus.

             439. Further, where one thing (233).

             Here he gives the third argument, which makes use of the notions "better or worse." For in all those cases where one thing is better than another, that which is better is always prior in nature. But there cannot be held to be one common genus of those things which exist in this way. Hence there cannot be held to be one separate genus in the case of those things in which one is better and another worse; and thus the conclusion is the same as the above. For this argument is introduced to strengthen the preceding one, so to speak, i.e., with a view to showing that there is priority and posteriority among the species of any genus.

             440. And from these three arguments he draws the conclusion in which he is chiefly interested, namely, that the lowest species, which are predicated immediately of individuals, seem to be the principles of things to a greater degree than genera.

             441. But again it is not (234).

             Here he argues the opposite side of the question, as follows: a principle and a cause are distinct from the things of which they are the principle and cause, and are capable of existing apart from them. And this is true, because nothing is its own cause. He is speaking here of extrinsic principles and causes, which are causes of a thing in its entirety. But the only thing that is held to exist apart from singular things is what is commonly and universally predicated of all things. Therefore the more universal a thing is, the more separate it is, and the more it should be held to be a principle. But the first genera are most universal. Therefore the first genera are the principles of things in the highest degree.

             442. Now the solution to these questions is implied in this last argument. For according to this argument genera or species are held to be universal principles inasmuch as they are held to be separate. But the fact that they are not separate and self-subsistent is shown in Book VII (659:C 1592) of this work. Hence the Commentator also shows, in Book VIII, that the principles of things are matter and form, to which genus and species bear some likeness. For a genus is derived from matter and difference from form, as will be shown in the same book (716:C 1721). Hence, since form is more of a principle than matter, species will consequently be principles more than genera. But the objection which is raised against this, on the grounds that genera are the principles of knowing a species and its definitions, is answered in the same way as the objection raised about their separateness. For, since a genus is understood separately by the mind without understanding its species, it is a principle of knowing. And in the same way it would be a principle of being, supposing that it had a separate being.