A History of Western Philosophy

by Bertrand Russell

  It is difficult to decide at what point to begin an account of Aristotle’s metaphysics, but perhaps the best place is his criticism of the theory of ideas and his own alternative doctrine of universals. He advances against the ideas a number of very good arguments, most of which are already to be found in Plato’s Parmenides. The strongest argument is that of the “third man”: if a man is a man because he resembles the ideal man, there must be a still more ideal man to whom both ordinary men and the ideal man are similar. Again, Socrates is both a man and an animal, and the question arises whether the ideal man is an ideal animal; if he is, there must be as many ideal animals as there are species of animals. It is needless to pursue the matter; Aristotle makes it obvious that, when a number of individuals share a predicate, this cannot be because of relation to something of the same kind as themselves, but more ideal. This much may be taken as proved, but Aristotle’s own doctrine is far from clear. It was this lack of clarity that made possible the medieval controversy between nominalists and realists.

  Aristotle’s metaphysics, roughly speaking, may be described as Plato diluted by common sense. He is difficult because Plato and common sense do not mix easily. When one tries to understand him, one thinks part of the time that he is expressing the ordinary views of a person innocent of philosophy, and the rest of the time that he is setting forth Platonism with a new vocabulary. It does not do to lay too much stress on any single passage, because there is liable to be a correction or modification of it in some later passage. On the whole, the easiest way to understand both his theory of universals and his theory of matter and form is to set forth first the common-sense doctrine which is half of his view, and then to consider the Platonic modifications to which he subjects it.

  Up to a certain point, the theory of universals is quite simple. In language, there are proper names, and there are adjectives. The proper names apply to “things” or “persons,” each of which is the only thing or person to which the name in question applies. The sun, the moon, France, Napoleon, are unique; there are not a number of instances of things to which these names apply. On the other hand, words like “cat,” “dog,” “man” apply to many different things. The problem of universals is concerned with the meanings of such words, and also of adjectives, such as “white,” “hard,” “round,” and so on. He says:* “By the term ‘universal’ I mean that which is of such a nature as to be predicated of many subjects, by ‘individual’ that which is not thus predicated.”

  What is signified by a proper name is a “substance,” while what is signified by an adjective or class-name, such as “human” or “man,” is called a “universal.” A substance is a “this,” but a universal is a “such”—it indicates the sort of thing, not the actual particular thing. A universal is not a substance, because it is not a “this.” (Plato’s heavenly bed would be a “this” to those who could perceive it; this is a matter as to which Aristotle disagrees with Plato.) “It seems impossible,” Aristotle says, “that any universal term should be the name of a substance. For … the substance of each thing is that which is peculiar to it, which does not belong to anything else; but the universal is common, since that is called universal which is such as to belong to more than one thing.” The gist of the matter, so far, is that a universal cannot exist by itself, but only in particular things.

  Superficially, Aristotle’s doctrine is plain enough. Suppose I say, “there is such a thing as the game of football,” most people would regard the remark as a truism. But if I were to infer that football could exist without football-players, I should be rightly held to be talking nonsense. Similarly, it would be held, there is such a thing as parenthood, but only because there are parents; there is such a thing as sweetness, but only because there are sweet things; and there is redness, but only because there are red things. And this dependence is thought to be not reciprocal: the men who play football would still exist even if they never played football; things which are usually sweet may turn sour; and my face, which is usually red, may turn pale without ceasing to be my face. In this way we are led to conclude that what is meant by an adjective is dependent for its being on what is meant by a proper name, but not vice versa. This is, I think, what Aristotle means. His doctrine on this point, as on many others, is a common-sense prejudice pedantically expressed.

  But it is not easy to give precision to the theory. Granted that football could not exist without football-players, it could perfectly well exist without this or that football-player. And granted that a person can exist without playing football, he nevertheless cannot exist without doing something. The quality redness cannot exist without some subject, but it can exist without this or that subject; similarly a subject cannot exist without some quality, but can exist without this or that quality. The supposed ground for the distinction between things and qualities thus seems to be illusory.

  The true ground of the distinction is, in fact, linguistic; it is derived from syntax. There are proper names, adjectives, and relation-words; we may say “John is wise, James is foolish, John is taller than James,” Here “John” and “James” are proper names, “wise” and “foolish” are adjectives, and “taller” is a relation-word. Metaphysicians, ever since Aristotle, have interpreted these syntactical differences metaphysically: John and James are substances, wisdom and folly are universals. (Relation-words were ignored or misinterpreted.) It may be that, given sufficient care, metaphysical differences can be found that have some relation to these syntactical differences, but, if so, it will be only by means of a long process, involving, incidentally, the creation of an artificial philosophical language. And this language will contain no such names as “John” and “James,” and no such adjectives as “wise” and “foolish”; all the words of ordinary languages will have yielded to analysis, and been replaced by words having a less complex significance. Until this labour has been performed, the question of particulars and universals cannot be adequately discussed. And when we reach the point at which we can at last discuss it, we shall find that the question we are discussing is quite quite different from what we supposed it to be at the outset.

  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 “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 ves
sel, 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 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 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 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 is that actuality; and God’s self-dependent actuality is life most good and eternal. We say therefore that God is a living being, eternal, most good, so that life and duration continuous and eternal belong to God; for this is God” (1072b).

  “It is clear then from what has been said that there is a substance which is eternal and unmovable and separate from sensible things, It has been shown that this substance cannot have any magnitude, but is without parts and indivisible…. But it has also been shown that it is impassive and unalterable; for all the other changes are posterior to change of place” (1073a).

  God does not have the attributes of a Christian Providence, for it would derogate from His perfection to think about anything except what is perfect, i.e. Himself. “It must be of itself that the divine thought thinks (since it is the most excellent of things), and its thinking is a thinking on thinking.” (1074b). We must infer that God does not know of the existence of our sublunary world. Aristotle, like Spinoza, holds that, while men must love God, it is impossible that God should love men.

  God is not definable as “the unmoved mover.” On the contrary, astronomical considerations lead to the conclusion that there are either forty-seven or fifty-five unmoved movers (1074a). The relation of these to God is not made clear; indeed the natural interpretation would be that there are forty-seven or fifty-five gods. For after one of the above passages on God Aristotle proceeds: “We must not ignore the question whether we are to suppose one such substance or more than one,” and at once embarks upon the argument that leads to the forty-seven or fifty-five unmoved movers.

  The conception of an unmoved mover is a difficult one. To a modern mind, it would seem that the cause of a change must be a previous change, and that, if the universe were ever wholly static, it would remain so eternally. To understand what Aristotle means, we
must take account of what he says about causes. There are, according to him, four kinds of causes, which were called, respectively, material, formal, efficient, and final. Let us take again the man who is making a statue. The material cause of the statue is the marble, the formal cause is the essence of the statue to be produced, the efficient cause is the contact of the chisel with the marble, and the final cause is the end that the sculptor has in view. In modern terminology, the word “cause” would be confined to the efficient cause. The unmoved mover may be regarded as a final cause: it supplies a purpose for change, which is essentially an evolution towards likeness with God.

  I said that Aristotle was not by temperament deeply religious, but this is only partly true. One could, perhaps, interpret one aspect of his religion, somewhat freely, as follows:

  God exists eternally, as pure thought, happiness, complete self-fulfilment, without any unrealized purposes. The sensible world, on the contrary, is imperfect, but it has life, desire, thought of an imperfect kind, and aspiration. All living things are in a greater or less degree aware of God, and are moved to action by admiration and love of God. Thus God is the final cause of all activity. Change consists in giving form to matter, but, where sensible things are concerned, a substratum of matter always remains. Only God consists of form without matter. The world is continually evolving towards a greater degree of form, and thus becoming progressively more like God. But the process cannot be completed, because matter cannot be wholly eliminated. This is a religion of progress and evolution, for God’s static perfection moves the world only through the love that finite beings feel for Him. Plato was mathematical, Aristotle was biological; this accounts for the differences in their religions.