In reading any important philosopher, but most of all in reading Aristotle, it is necessary to study him in two ways: with reference to his predecessors, and with reference to his successors. In the former aspect, Aristotle's merits are enormous; in the latter, his demerits are equally enormous. For his demerits, however, his successors are more responsible than he is. He came at the end of the creative period in Greek thought, and after his death it was two thousand years before the world produced any philosopher who could be regarded as approximately his equal. Towards the end of this long period his authority had become almost as unquestioned as that of the Church, and in science, as well as in philosophy, had become a serious obstacle to progress. Ever since the beginning of the seventeenth century, almost every serious intellectual advance has had to begin with an attack on some Aristotelian doctrine; in logic, this is still true at the present day. But it would have been at least as disastrous if any of his predecessors (except perhaps Democritus) had acquired equal authority. To do him justice, we must, to begin with, forget his excessive posthumous fame, and the equally excessive posthumous condemnation to which it led.
Aristotle was born, probably in 384 B.C., at Stagira in Thrace. His father had inherited the position of family physician to the king of Macedonia. At about the age of eighteen Aristotle came to Athens and became a pupil of Plato; he remained in the Academy for nearly twenty years, until the death of Plato in 348–7 B.C. He then travelled for a time, and married either the sister or the niece of a tyrant named Hermias. (Scandal said she was the daughter or concubine of Hermias, but both stories are disproved by the fact that he was a eunuch.) In 343 B.C. he became tutor to Alexander, then thirteen years old, and continued in that position until, at the age of sixteen, Alexander was pronounced by his father to be of age, and was appointed regent during Philip's absence. Everything one would wish to know of the relations of Aristotle and Alexander is unascertainable, the more so as legends were soon invented on the subject. There are letters between them which are generally regarded as forgeries. People who admire both men suppose that the tutor influenced the pupil. Hegel thinks that Alexander's career shows the practical usefulness of philosophy. As to this, A. W. Benn says: 'It would be unfortunate if philosophy had no better testimonial to show for herself than the character of Alexander…. Arrogant, drunken, cruel, vindictive, and grossly superstitious, he united the vices of a Highland chieftain to the frenzy of an Oriental despot.'1
For my part, while I agree with Benn about the character of Alexander, I nevertheless think that his work was enormously important and enormously beneficial, since, but for him, the whole tradition of Hellenic civilization might well have perished. As to Aristotle's influence on him, we are left free to conjecture whatever seems to us most plausible. For my part, I should suppose it nil. Alexander was an ambitious and passionate boy, on bad terms with his father, and presumably impatient of schooling. Aristotle thought no State should have as many as one hundred thousand citizens,2 and preached the doctrine of the golden mean. I cannot imagine his pupil regarding him as anything but a prosy old pedant, set over him by his father to keep him out of mischief. Alexander, it is true, had a certain snobbish respect for Athenian civilization, but this was common to his whole dynasty who wished to prove that they were not barbarians. It was analogous to the feeling of nineteenth-century Russian aristocrats for Paris. This, therefore, was not attributable to Aristotle's influence. And I do not see anything else in Alexander that could possibly have come from this source.
It is more surprising that Alexander had so little influence on Aristotle, whose speculations on politics were blandly oblivious of the fact that the era of City States had given way to the era of empires. I suspect that Aristotle, to the end, thought of him as 'that idle and headstrong boy, who never could understand anything of philosophy'. On the whole, the contacts of these two great men seem to have been as unfruitful as if they had lived in different worlds.
From 335 B.C. to 323 B.C. (in which latter year Alexander died), Aristotle lived at Athens. It was during these twelve years that he founded his school and wrote most of his books. At the death of Alexander, the Athenians rebelled, and turned on his friends, including Aristotle, who was indicted for impiety, but, unlike Socrates, fled to avoid punishment. In the next year (322) he died.
Aristotle, as a philosopher, is in many ways very different from all his predecessors. He is the first to write like a professor: his treatises are systematic, his discussions are divided into heads, he is a professional teacher, not an inspired prophet. His work is critical, careful, pedestrian, without any trace of Bacchic enthusiasm. The Orphic elements in Plato are watered down in Aristotle, and mixed with a strong dose of common sense; where he is Platonic, one feels that his natural temperament has been overpowered by the teaching to which he has been subjected. He is not passionate, or in any profound sense religious. The errors of his predecessors were the glorious errors of youth attempting the impossible; his errors are those of age which cannot free itself of habitual prejudices. He is best in detail and in criticism; he fails in large construction, for lack of fundamental clarity and Titanic fire.
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 theory of 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:3 '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 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 notion, 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 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:4
'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 hypostatize 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 not consistent with the rest of his views unless 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.
This would, however, be a one-sided view of Aristotle's religion; he has also the Greek love of static perfection and preference for contemplation rather than action. His doctrine of the soul illustrates this aspect of his philosophy.
Whether Aristotle taught immortality in any form, or not, was a vexed question among commentators. Averroes, who held that he did not, had followers in Christian countries, of whom the more extreme were called Epicureans, and whom Dante found in hell. In fact, Aristotle's doctrine is complex, and easily lends itself to misunderstandings. In his book On the Soul, he regards the soul as bound up with the body, and ridicules the Pythagorean doctrine of transmigration (407b). The soul, it seems, perishes with the body: 'it indubitably follows that the soul is inseparable from its body' (413a); but he immediately adds: 'or at any rate certain parts of it are'. Body and soul are related as matter and form: 'the soul must be a substance in the sense of the form of a material body having life potentially within it. But substance is actuality, and thus soul is the actuality of a body as above characterized' (412a). Soul 'is substance in the sense which corresponds to the definitive formula of a thing's essence. That means that it is the "essential whatness" of a body of the character just assigned' (i.e. having life) (412b). The soul is the first grade of actuality of a natural body having life potentially in it. The body so described is a body which is organized (412a). To ask whether soul and body are one is as meaningless as to ask whether the wax and the shape given it by the stamp are one (412b). Self-nutrition is the only psychic power possessed by plants (413a). The soul is the final cause of the body (414a).
In this book, he distinguishes between 'soul' and 'mind', making mind higher than soul, and less bound to the body. After speaking of the relation of soul and body, he says: 'The case of mind is different; it seems to be an independent substance implanted within the soul and to be incapable of being destroyed' (408b). Again: 'We have no evidence as yet about mind or the power to think; it seems to be a widely different kind of soul, differing as what is eternal from what is perishable; it alone is capable of existence in isolation from all other psychic powers. All the other parts of soul, it is evident from what we have said, are, in spite of certain statements to the contrary, incapable of separate existence' (413b). The mind is the part of us that understands mathematics and philosophy; its objects are timeless, and therefore it is regarded as itself timeless. The soul is what moves the body and perceives sensible objects; it is characterized by self-nutrition, sensation, feeling, and motivity (413b); but the mind has the higher function of thinking, which has no relation to the body or to the senses. Hence the mind can be immortal, though the rest of the soul cannot.
To understand Aristotle's doctrine of the soul, we must remember that the soul is the 'form' of the body, and that spatial shape is one kind of 'form'. What is there in common between soul and shape? I think what is in common is the conferring of unity upon a certain amount of matter. The part of a block of marble which afterwards becomes a statute is, as yet, not separated from the rest of the marble; it is not yet a 'thing', and has not yet any unity. After the sculptor has made the statue, it has unity, which it derives from its shape. Now the essential feature of the soul, in virtue of which it is the 'form' of the body, is that it makes the body an organic whole, having purposes as a unit. A single organ has purposes lying outside itself; the eye, in isolation, cannot see. Thus many things can be said in which an animal or plant as a whole is the subject, which cannot be said about any part of it. It is in this sense that organization, or form, confers substantiality. That which confers substantiality upon a plant or animal is what Aristotle calls its 'soul'. But 'mind' is something different, less intimately bound up with the body; perhaps it is a part of the soul, but it is possessed by only a small minority of living beings (415a). Mind as speculation cannot be the cause of movement, for it never thinks about what is practicable, and never says what is to be avoided or what pursued (432b).
A similar doctrine, though with a slight change of terminology, is set forth in the Nicomachean Ethics. There is in the soul one element that is rational, and one that is irrational. The irrational part is two-fold: the vegetative, which is found in everything living, even in plants, and the appetitive, which exists in all animals (1102b). The life of the rational soul consists in contemplation, which is the complete happiness of man though not fully attainable. 'Such a life would be too high for man; for it is not in so far as he is man that he will live so, but in so far as something divine is present in him; and by so much as this is superior to our composite nature is its activity superior to that which is the exercise of the other kind of virtue (the practical kind). If reason is divine, then, in comparison with man, the life in accordance with it is divine in comparison with human life. But we must not follow those who advise us, being men, to think of human things, and being mortal, of mortal things, but must, so far as we can, make ourselves immortal, and strain every nerve to live in accordance with the best thing in us; for even if it be small in bulk, much more does it in power and worth surpass everything' (1177b).
It seems, from these passages, that individuality—what distinguishes one man from another—is connected with the body and the irrational soul, while the rational soul or mind is divine and impersonal. One man likes oysters, and another likes pineapples; this distinguishes between them. But when they think about the multiplication table, provided they think correctly, there is no difference between them. The irrational separates us, the rational unites us. Thus the immortality of mind or reason is not a personal immortality of separate men, but a share in God's immortality. It does not appear that Aristotle believed in personal immortality, in the sense in which it was taught by Plato and afterwards by Christianity. He believed only that, in so far as men are rational, they partake of the divine, which is immortal. It is open to man to increase the element of the divine in his nature, and to do so is the highest virtue. But if he succeeded completely, he would have ceased to exist as a separate person. This is perhaps not the only possible interpretation of Aristotle's words, but I think it is the most natural.