Lecture 1 — Metaphysics studies substance

The study here is concerned with substance, for it is the principles and causes of substances which are being investigated.

For if the totality of things is a kind of whole, substance is its first part; and if things constitute a whole by reason of succession, substance is also first, and then quality or quantity.

But in like manner, the latter are not to be regarded as beings in an unqualified sense, but as qualities and motions of being. Otherwise the not-straight and not-white would be beings, for we say that they exist—such as when we say, “it is non-white.”

Again, none of the other genera can exist separately.

The ancient philosophers testify to this in practice, for it was of substance that they sought the principles, elements and causes.

Present-day thinkers, however, maintain that universals are substances; for genera are universals, and they say that these are principles and substances to a greater degree because they investigate the matter logically.

But the ancient philosophers regarded particular things as substances, such as fire and earth, though not a common body.

2416. Having summarized in the preceding book the points that were previously made regarding imperfect being both in this work and in the Physics, in this book, the Philosopher aims to summarize the things that have been said about being in its unqualified sense (namely, substance), both in books 7 and 8 of this work and in Physics 1, and to add anything that is missing in order to make his study of substances complete. This is divided into two parts.

First (1069a18; [2416]), he shows that this science is chiefly concerned with substances.

Second (1069a30; [2424]), he gives his views about the kinds of substances, at now, there are three.

In regard to the first, he does two things.

First, he states his thesis. He says that, in this science, the study, that is, the principal inquiry, is concerned with substance. For, since this science, being the first and the one called wisdom, investigates the first principles of beings, the principles and causes of substances must constitute its main object of study; for these are the first principles of beings. The way in which principle and cause differ has been pointed out in book 5 (1012b34; [760]).

2417. For if the totality (1069a19). He proves his thesis in four ways.

The first proof runs thus. Since substance is prior to the other kinds of beings, the first science should be one that is chiefly concerned with the primary kind of being. He shows that substance is the primary kind of being by using an analogous case in the realm of sensible things, among which, order is found in two ways.

One kind of order is found among sensible things inasmuch as the parts of any whole have a certain natural arrangement. For example, the first part of an animal is the heart, and the first part of a house, the foundation.

Another kind of order is found among sensible things inasmuch as some follow others and one thing is not constituted from them either by continuity or by contact. It is in this sense that one speaks of the first and second lines of an army.

Hence, just as there is some first part in any whole, and also some first entity among things that follow one another, so too substance is the first of all other beings. This is what he means when he says, for if the totality, that is, the universe of beings, is a kind of whole, substance is its first part, just as the foundation is the first part of a house. And if beings are like things that follow one another, substance again will be first, and then quantity, and then the other categories.

2418. But Averroes, failing to consider that this statement is analogical because he considered it impossible for anyone to think that all the other genera of beings should be parts of one continuous whole, departs from the obvious sense of the text and explains it in a different way. He says that by these two orders Aristotle meant the twofold relationship which can be conceived between things.

The first is that beings are related as things having one nature and one genus, which would be true if being were their common genus, or in whatever way it might be common to them. He says that this is Aristotle’s meaning when he says, if the totality of things is a kind of whole.

The second is that beings are related as things having nothing in common. He says that this is Aristotle’s meaning when he says, and if things constitute a whole by reason of succession. For, in either case, it follows that substance is prior to the other kinds of being.

2419. But in like manner (1069a22). Then he gives a second proof of his thesis. He says that quantity and quality and the like are not beings in an unqualified sense, as will be said below. For being means something having existence, but it is substance alone that subsists. And accidents are called beings not because they are, but rather because, by them, something is; for example, whiteness is said to be because, by it, the subject is white. Hence, Aristotle says that accidents, as quality and motion, are not called beings in an unqualified sense, but beings of a being.

2420. Nor is it surprising if accidents are called beings even though they are not beings in an unqualified sense, since even privations and negations are called beings in a sense, like the not-white and the not-straight. For we say that the not-white “is” not because the not-white has being, but because some subject is deprived of whiteness.

Accidents and privations have this in common, then: being is predicated of both by reason of their subject.

Yet they differ in this respect: while a subject has being of some kind by reason of its accidents, it does not have being of any kind by reason of privations, but is deficient in being.

2421. Therefore, since accidents are not beings in an unqualified sense, but only substances are, this science, which considers being as being, is not chiefly concerned with accidents, but with substances.

2422. Again, none (1069a24). Then he gives a third proof of his thesis that the other kinds of beings cannot exist apart from substance. For accidents can exist only in a subject, and therefore, the study of accidents is included in that of substance.

2423. The ancient philosophers (1069a25). He gives a fourth proof of his thesis. He says that the ancient philosophers also testify to the fact that the philosopher is concerned with substances, for in seeking the causes of being, they looked for the causes only of substance.

And some of the moderns also did this, but in a different way; for they did not seek principles, causes, and elements in the same way, but differently. For the moderns—the Platonists—claimed that universals are substances to a greater degree than particular things, for they said that genera, which are universals, are principles and causes of substances to a greater degree than particular things. They did this because they investigated things from the viewpoint of logic, for they thought that universals, which are separate according to their mode of definition from sensible things, are also separate in reality, and that they are the principles of particular things. But the ancient philosophers, such as Democritus and Empedocles, claimed that the substances and principles of things are particular entities, such as fire and earth, but not this common principle, body.