A Critical History of Greek Philosophy, W. T. Stace [best books to read for students txt] 📗

individual man there must be yet another Idea to explain what they have in common, and so on ad infinitum.

(7) But by far the most important of all Aristotle's objections to the ideal theory, and that which, to all intents and purposes, sums up all the others, is that it assumes that Ideas are the essences of things, and yet places those essences outside the things themselves. The essence of a thing must be in it, and not outside it. But Plato separated Ideas from things, and placed the Ideas away somewhere in a mysterious world of their own. The Idea, as the universal, can only exist in the particular. Possibly the reality in all horses is the universal horse, but the universal horse is not something that exists by itself and independently of individual horses. Hence Plato was led into the absurdity of talking as if, besides the individual horses we know, there is somewhere another individual called the horse-in-general, or as if besides white objects there is a thing called {265} whiteness. And this is in fact the supreme self-contradiction of the theory of Ideas, that it begins by saying that the universal is real, and the particular unreal, but ends by degrading the universal again into a particular. This is the same thing as saying that Plato's mistake lay in first (rightly) seeing that existence is not reality, but then (wrongly) going on to imagine that the reality is an existence.

Out of this last objection grows Aristotle's own philosophy, the fundamental principle of which is that the universal is indeed the absolute reality, but that it is a universal which exists only in the particular. What is reality? What is substance? This is the first question for the metaphysician. Now substance is what has an independent existence of its own; it is that whose being does not flow into it from any source outside itself. Consequently, substance is what is never a predicate; it is that to which all predicates are applied. Thus in the proposition, "Gold is heavy," gold is the subject, or substance, and "heavy" is its predicate. The heaviness is dependent for its existence on the gold, and it is therefore the latter, and not the former, that is the substance.

Now, keeping this in mind, are universals, as Plato asserts, substances? No; because the universal is merely a common predicate which attaches to many objects of a class. Thus the concept of man is merely what is common to all men. It is the same thing as the predicate "humanness." But humanness cannot exist apart from human beings, any more than heaviness apart from the heavy object. Universals, then, are not substances. But neither are particulars substances. For there is no such thing as that which is absolutely {266} particular and isolated. If humanness does not exist apart from men, neither do men exist apart from humanness. Take away from a man what he has in common with other men, and what he has in common with other objects, and you will find that, having stripped him of all his qualities, there is absolutely nothing left. We say gold is heavy, yellow, malleable, etc. Now the heaviness, the yellowness, and the other qualities, cannot exist apart from the gold. But it is equally true that the gold cannot exist apart from its qualities. Strip off all its qualities in thought, and then ask yourself what the gold itself is apart from its qualities. You will find that your mind is a total blank. In taking away the qualities you have taken away the gold itself. The gold can only be thought through its qualities. It only exists through its qualities. The gold, therefore, just as much depends on the qualities for its existence as the qualities depend upon the gold. Hence neither of them, considered apart from the other, is substance. But the qualities are the universal element in the gold, the gold without the qualities is the absolutely particular and isolated. For, first, the yellowness is a quality which this gold has in common with that gold, and is therefore a universal, and so with all the qualities. Even if a particular piece of gold has a quality possessed by no other gold, it is yet possessed by some other object in the universe, or it would be unknowable. Every quality is consequently a universal. Secondly, the gold without its qualities is the absolutely particular. For, being stripped of all qualities, it is stripped of whatever it has in common with other things; it is stripped of whatever universality it has, and it remains an absolute particular. Hence the {267} universal is not substance, nor is the particular. For neither of them can exist without the other. Substance must be a compound of the two; it must be the universal in the particular. And this means that that alone which is substance is the individual object, for example, the gold with all its qualities attached to it.

It is usually believed that Aristotle contradicted himself in as much as he first states, as above, that the individual object, the compound of universal and particular, is substance, but later on allows a superior reality to the universal, or "form" as he calls it, and in effect teaches, like Plato, that the universal is what alone is absolutely real, that is, that the universal is substance. I do not agree that there is any real inconsistency in Aristotle. Or rather, the inconsistency is one of words and not of thought. It must be remembered that, whenever Aristotle says that the individual, and not the universal, is substance, he is thinking of Plato. What he means to deny is that the universal can exist on its own account, as Plato thought. Nevertheless he agrees with Plato that the universal is the real. When he says that the universal is not substance he means, as against Plato, that it is not existent. What alone exists is the individual thing, the compound of universal and particular. When he says, or implies, that the universal is substance, he means that, though it is not existent, it is real. His words are contradictory, but his meaning is not. He has not expressed himself as clearly as he should; that is all.

The further development of Aristotle's metaphysics depends upon his doctrine of causation. By causation here, however, is meant a very much wider conception {268} than what is understood by that term in modern times. I have in previous lectures attempted to make clear the distinction between causes and reasons. The cause of a thing does not give any reason for it, and therefore does not explain it. The cause is merely the mechanism by which a reason produces its consequence. Death is caused by accident or disease, but these causes explain nothing as to why death should be in the world at all. Now if we accept this distinction, we may say that Aristotle's conception of causation includes both what we have called causes and reasons. Whatever is necessary, whether facts or principles, whether causes or reasons, fully to understand the existence of a thing, or the happening of an event, is included in the Aristotelian notion of causation.

Taking causation in this wide sense, Aristotle finds that there are four kinds of causes, the material, the efficient, the formal, and the final cause. These are not alternative causes; it is not meant that, to explain anything, one or other of the four must be present. In every case of the existence or production of a thing all four causes operate simultaneously. Moreover the same four causes are to be found both in human and in cosmic production, in the making of manufactured articles by man and in the production of things by nature. They are more clearly and easily seen, however, in human production, from which sphere, therefore, we select our example. The material cause of a thing is the matter of which it is composed. It is the raw material which becomes the thing. For example, in the making of a bronze statue of Hermes, the bronze is the material cause of the statue. This example might lead one to suppose {269} that Aristotle means by material cause what we call matter, physical substance, such as brass, iron, or wood. As we shall see later, this is not necessarily the case, though it is so in the present instance. The efficient cause is always defined by Aristotle as the cause of motion. It is the energy or moving force required to bring about change. It must be remembered that by motion Aristotle means not merely change of place but change of any sort. The alteration of a leaf from green to yellow is just as much motion, in his sense, as the falling of a stone. The efficient cause, then, is the cause of all change. In the example taken, what causes the bronze to become a statue, what produces this change, is the sculptor. He is, therefore, the efficient cause of the statue. The formal cause Aristotle defines as the substance and essence of the thing. Now the essence of a thing is given in its definition. But the definition is the explication of the concept. Therefore the formal cause is the concept, or, as Plato would call it, the Idea of the thing. Plato's Ideas thus reappear in Aristotle as formal causes. The final cause is the end, purpose, or aim, towards which the movement is directed. When a statue is being produced, the end of this activity, what the sculptor aims at, is the completed statue itself. And the final cause of a thing in general is the thing itself, the completed being of the object.

We can see at once how much wider this conception of causation is than the modern conception. If we take Mill's definition of a cause as the best expression of modern scientific ideas, we find that he defines a cause as the "invariable and unconditional antecedent of a phenomenon." This cuts out final causes at once. For {270} the final cause is the end, and is not an antecedent in time. It also does not include formal causes. For we do not now think of the concept of a thing as being part of its cause. This leaves us with only material and efficient causes, and these correspond roughly to the modern notions of matter and energy. Even the efficient causes of Aristotle, however, appear on further consideration, to be excluded from the modern idea of causation. For, though the efficient cause is the energy which produces motion, modern science regards it as purely mechanical energy, whereas Aristotle thinks of it, as we shall see, as an ideal force, operating not from the beginning but from the end. But it must not be supposed that, in saying that the modern idea of causation excludes formal and final causes, we mean that Aristotle is wrong in adding them, or that the modern idea is better than Aristotle's. It is not a question of better and worse at all. Modern science does not in any way deny the reality of formal and final causes. It merely considers them to be outside its sphere. It is no business of science whether they exist or not. As knowledge advances, differentiation and division of labour occur. Science takes as its province mechanical causes, and leaves formal and final causes to the philosopher to explicate. Thus, for example, formal causes are not considered by science because they are not, in the modern sense, causes at all. They are what we have called reasons. If we are to explain the existence of an object in the universe it may be necessary to introduce formal causes, concepts, to show why the thing exists, to show in fact its reasons. But science makes no attempt to explain the existence of objects. It takes their