If, therefore, I have failed to make Aristotle’s theory of universals clear, that is (I maintain) because it is not clear. But it is certainly an advance on the theory of ideas, and is certainly concerned with a genuine and very important problem.
There is another term which is important in Aristotle and in his scholastic followers, and that is the term «essence.» This is by no means synonymous with «universal.» Your «essence» is «what you are by your very nature.» It is, one may say, those of your properties which you cannot lose without ceasing to be yourself. Not only an individual thing, but a species, has an essence. The definition of a species should consist in mentioning its essence. I shall return to the conception of
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«essence» in connection with Aristotle’s logic. For the present I will merely observe that it seems to me a muddle-headed action, incapable of precision.
The next point in Aristotle’s metaphysics is the distinction of «form» and «matter.» (It must be understood that «matter,» in the sense in which it is opposed to «form,» is different from «matter» as opposed to «mind.»)
Here, again, there is a common-sense basis for Aristotle’s theory, but here, more than in the case of universals, the Platonic modifications are very important. We may start with a marble statue; here marble is the matter, while the shape conferred by the sculptor is the form. Or, to take Aristotle’s examples, if a man makes a bronze sphere, bronze is the matter, and sphericity is the form; while in the case of a calm sea, water is the matter and smoothness is the form. So far, all is simple.
He goes on to say that it is in virtue of the form that the matter is some one definite thing, and this is the substance of the thing. What Aristotle means seems to be plain common sense: a «thing» must be bounded, and the boundary constitutes its form. Take, say, a volume of water: any part of it can be marked off from the rest by being enclosed in a vessel, and then this part becomes a «thing,» but so long as the part is in no way marked out from the rest of the homogeneous mass it is not a «thing.» A statue is a «thing,» and the marble of which it is composed is, in a sense, unchanged from what it was as part of a lump or as part of the contents of a quarry. We should not naturally say that it is the form that confers substantiality, but that is because the atomic hypothesis is ingrained in our imagination. Each atom, however, if it is a «thing,» is so in virtue of its being delimited from other atoms, and so having, in some sense, a «form.»
We now come to a new statement, which at first sight seems difficult. The soul, we are told, is the form of the body. Here it is clear that «form» does not mean «shape.» I shall return later to the sense in which the soul is the form of the body; for the present, I will only observe that, in Aristotle’s system, the soul is what makes the body one thing, having unity of purpose, and the characteristics that we associate with the word «organism.» The purpose of an eye is to see, but it cannot see when parted from its body. In fact, it is the soul that sees.
It would seem, then, that «form» is what gives unity to a portion
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of matter, and that this unity is usually, if not always, teleological. But «form» turns out to be much more than this, and the more is very difficult.
The form of a thing, we are told, is its essence and primary substance. Forms are substantial, although universals are not. When a man makes a brazen sphere, both the matter and the form already existed, and all that he does is to bring them together; the man does not make the form, any more than he makes the brass. Not everything has matter; there are eternal things, and these have no matter, except those of them that are movable in space. Things increase in actuality by acquiring form; matter without form is only a potentiality.
The view that forms are substances, which exist independently of the matter in which they are exemplified, seems to expose Aristotle to his own arguments against Platonic ideas. A form is intended by him to be something quite different from a universal, but it has many of the same characteristics. Form is, we are told, more real than matter; this is reminiscent of the sole reality of the ideas. The change that Aristotle makes in Plato’s metaphysic is, it would seem, less than he represents it as being. This view is taken by Zeller, who, on the question of matter and form,
says: *
The final explanation of Aristotle’s want of clearness on this subject is, however, to be found in the fact that he had only half emancipated himself, as we shall see, from Plato’s tendency to hypostatise ideas. The ‘Forms’ had for him, as the ‘Ideas’ had for Plato, a metaphysical existence of their own, as conditioning all individual things. And keenly as he followed the growth of ideas out of experience, it is none the less true that these ideas, especially at the point where they are farthest removed from experience and immediate perception, are metamorphosed in the end from a logical product of human thought into an immediate presentment of a supersensible world, and the object, in that sense, of an intellectual intuition.
I do not see how Aristotle could have found a reply to this criticism.
The only answer that I can imagine would be one that maintained that no two things could have the same form. If a man makes two brass spheres (we should have to say), each has its own special
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* Aristotle, Vol. I, p. 204.
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sphericity, which is substantial and particular, an instance of the universal «sphericity,» but not identical with it. I do not think the language of the passages I quoted would readily support this interpretation. And it would be open to the objection that the particular sphericity would, on Aristotle’s view, be unknowable, whereas it is of the essence of his metaphysics that, as there comes to be more of form and less of matter, things become gradually more knowable. This is only consistent with the rest of his views if the form can be embodied in many particular things. If he were to say that there are as many forms that are instances of sphericity as there are spherical things, he would have to make very radical alterations in his philosophy. For instance, his view that a form is identical with its essence is incompatible with the above suggested escape.
The doctrine of matter and form in Aristotle is connected with the distinction of potentiality and actuality. Bare matter is conceived as a potentiality of form; all change is what we should call «evolution,» in the sense that after the change the thing in question has more form than before. That which has more form is considered to be more «actual.» God is pure form and pure actuality; in Him, therefore, there can be no change. It will be seen that this doctrine is optimistic and teleological: the universe and everything in it is developing towards something continually better than what went before.
The concept of potentiality is convenient in some connections, provided it is so used that we can translate our statements into a form in which the concept is absent. «A block of marble is a potential statue» means «from a block of marble, by suitable acts, a statue is produced.» But when potentiality is used as a fundamental and irreducible concept, it always conceals confusion of thought. Aristotle’s use of it is one of the bad points in his system.
Aristotle’s theology is interesting, and closely connected with the rest of his metaphysics—indeed, «theology» is one of his names for what we call «metaphysics.» (The book which we know under that name was not so called by him.)
There are, he says, three kinds of substances: those that are sensible and perishable, those that are sensible but not perishable, and those that are neither sensible nor perishable. The first class includes plants and animals, the second includes the heavenly bodies (which Aristotle
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believed to undergo no change except motion), the third includes the rational soul in man, and also God.
The main argument for God is the First Cause: there must be something which originates motion, and this something must itself be unmoved, and must be eternal, substance, and actuality. The object of desire and the object of thought, Aristotle says, cause movement in this way, without themselves being in motion. So God produces motion by being loved, whereas every other cause of motion works by being itself in motion (like a billiard ball). God is pure thought; for thought is what is best. «Life also belongs to God; for the actuality of thought is life, and God
