A critical history of Greek philosophy

by W. T. Stace

The theory of Ideas is not a something sprung suddenly upon the world out of Plato's brain. It has its roots in the past. It is, as Aristotle showed, the outcome of Eleatic, Heracleitean, and Socratic determinations. Fundamentally, however, it grows out of the distinction between sense and reason, which had been the common property of Greek thinkers since the time of Parmenides. Parmenides was the first to emphasize this distinction, and to teach that the truth is to be found by reason, the world of sense being illusory. Heracleitus, and even Democritus, were pronounced adherents of reason, as against sense. The crisis came with the Sophists, who attempted to obliterate the distinction altogether, and to find all knowledge in sensation, thus calling forth the opposition of Socrates and Plato. As against them Socrates pointed out that all knowledge is through concepts, reason: and Plato added to this that the concept is not a mere rule of thought but a metaphysical reality. This was the substance of the theory of Ideas. [{235}] Every philosophy which makes a systematic attempt to solve the riddle of the universe necessarily begins with a theory of the nature of that absolute and ultimate reality from which the universe is derived. This absolute reality we will call simply the Absolute. Plato's theory is that the Absolute consists of concepts. To say that the Absolute is reason, is thought, is concepts, is the universal--these are merely four different expressions of the same theory. Now this proposition, that the Absolute is reason, is the fundamental thesis of all idealism. Since Plato's time there have been several great idealistic systems of philosophy. That the Absolute is reason is the central teaching of them all. Plato, therefore, is the founder and initiator of all idealism. It is this that gives him his great place in the history of philosophy. That the Absolute is universal thought, this is what Plato has contributed to the philosophical speculation of the world. This is his crowning merit.

But we must go somewhat more into details. We must see how far he applied this principle successfully to the unravelment of the great problems of philosophy. In lecturing upon the Eleatics, I said that any successful philosophy must satisfy at least two conditions. It must give such an account of the Absolute, that the Absolute is shown as capable of explaining the world. It must be possible to deduce the actual world of facts from the first principle. Secondly, not only must this first principle explain the world; it must also explain itself. It must be really ultimate, that is, we must not, in order to understand it, have to refer to anything beyond and outside it. If we have to do so then our ultimate is not an ultimate at all; our first principle [{236}] is not first. That thing by means of which we explain it must itself be the ultimate reality. And besides being ultimate, our principle must be wholly intelligible. It must not be a mere ultimate mystery; for to reduce the whole world to an ultimate mystery is clearly not to explain it. Our first principle must, in a word, be self-explanatory. Let us apply this two-fold test to Plato's system. Let us see, firstly, whether the principle of Ideas explains the world, and secondly, whether it explains itself.

Does it explain the world? Is the actual existence of things, horses, trees, stars, men, explained by it? What, in the first place, is the relation between things and the Ideas? Things, says Plato, are "copies," or "imitations" of the Ideas. They "participate" in the Ideas. The Ideas are "archetypal" of things. Now all these phrases are mere poetic metaphors. They do not really tell us how things are related to Ideas. But suppose we ignore this, and assume, for the sake of argument, that we understand what is meant by "participation" and that things are, in the literal sense, "copies" of Ideas. The question still remains, why do such copies exist, how do they arise? Now, if this problem is to be solved, it is not enough to show, merely as a fact, that, by some mysterious act, copies of Ideas come into existence. There must be a reason for it, and this reason it is the business of philosophy to explain. This reason, too, must exist in the nature of the Ideas themselves, and not outside them. There must be, in the very nature of the Ideas, some inner necessity which forces them to reproduce themselves in things. This is what we [{237}] mean by saying that the Ideas are a sufficient explanation of the existence of things. But there is in Plato's Ideas no such necessity. The Ideas are defined as being the sole reality. They have already all reality in themselves. They are self-sufficient. They lack nothing. It is not necessary for them further to realize their being in the concrete manifestation of things, because they, as wholly real, need no realization. Why, then, should they not remain for ever simply as they are? Why should they go out of themselves into things? Why should they not remain in themselves and by themselves? Why should they need to reproduce themselves in objects? There are, we know, white objects in the universe. Their existence, we are told, is explained by the Idea of whiteness? But why should the Idea of whiteness produce white things? It is itself the perfect whiteness. Why should it stir itself? Why should it not remain by itself, apart, sterile, in the world of Ideas, for all eternity? We cannot see. There is in the Ideas no necessity urging them towards reproduction of themselves, and this means that they possess no principle for the explanation of things.

Nevertheless Plato has to make some attempt to meet the difficulty. And as the Ideas are themselves impotent to produce things, Plato, unable to solve the problem by reason, attempts to solve it by violence. He drags in the notion of God from nowhere in particular, and uses him as a deus ex machina. God fashions matter into the images of Ideas. The very fact that Plato is forced to introduce a creator shows that, in the Ideas themselves, there is no ground of explanation. Things ought to be explained by the Ideas themselves, [{238}] but as they are incapable of explaining anything, God is called upon to do their work for them. Thus Plato, faced with the problem of existence, practically deserts his theory of Ideas, and falls back upon a crude theism. Or if we say that the term God is not to be taken literally, and that Plato uses it merely as a figurative term for the Idea of Good, then this saves Plato from the charge of introducing a theism altogether inconsistent with his philosophy, but it brings us back to the old difficulty. For in this case, the existence of things must be explained by means of the Idea of the Good. But this Idea is just as impotent as the other Ideas.

In this connection, too, the dualism of Plato's system becomes evident. If everything is grounded in the one ultimate reality, the Ideas, then the entire universe must be clasped together in a system, all parts of which flow out of the Ideas. If there exists in the universe anything which stands aloof from this system, remains isolated, and cannot be reduced to a manifestation of the Ideas, then the philosophy has failed to explain the world, and we have before us a confessed dualism. Now not only has Plato to drag in God for the explanation of things, he has also to drag in matter. God takes matter and forms it into copies of the Ideas. But what is this matter, and where does it spring from? Clearly, if the sole reality is the Ideas, matter, like all else, must be grounded in the Ideas. But this is not the case in Plato's system. Matter appears as a principle quite independent of the Ideas. As its being is self-derived and original, it must be itself a substance. But this is just what Plato denies, calling it absolute [{239}] not-being. Yet since it has not its source in the Ideas or in anything outside itself, we must say that though Plato calls it absolute not-being, it is in fact an absolute being. The Ideas and matter stand face to face in Plato's system neither derived from the other, equally ultimate co-ordinate, absolute realities. This is sheer dualism.

The source of this dualism is to be found in the absolute separation which Plato makes between sense and reason. He places the world of sense on one side, the world of reason on the other, as things radically different and opposed. Hence it is impossible for him ever to bridge the gulf that he has himself created between them. We may expect the dualism of a philosophy which builds upon such premises to break out at numerous points in the system. And so indeed it does. It exhibits itself as the dualism of Ideas and matter, of the sense-world and the thought-world, of body and soul. Not, of course, that it is not quite right to recognize the distinction between sense and reason. Any genuine philosophy must recognize that. And no doubt too it is right to place truth and reality on the side of reason rather than sense. But although sense and reason are distinct, they must also be identical. They must be divergent streams flowing from one source. And this means that a philosophy which considers the absolute reality to be reason must exhibit sense as a lower form of reason. Because Plato fails to see the identity of sense and reason, as well as their difference, his philosophy becomes a continual fruitless effort to overreach the dualism thus generated.

Thus the answer to our first question, whether the theory of Ideas explains the world of things, must be [{240}] answered in the negative. Let us pass on to the second test. Is the principle of Ideas a self-explanatory principle? Such a principle must be understood purely out of itself. It must not be a principle, like that of the materialist, which merely reduces the whole universe to an ultimate mysterious fact. For even if it be shown that the reason of everything is matter, it is still open to us to ask what the reason of matter is. We cannot see any reason why matter should exist. It is a mere fact, which dogmatically forces itself upon our consciousness without giving any reason for itself. Our principle must be such that we cannot ask a further reason of it. It must be its own reason, and so in itself satisfy the demand for a final explanation. Now there is only one such principle in the world, namely, reason itself. You can ask the reason of everything else in the world. You can ask the reason of the sun, the moon, stars, the soul, God, or the devil. But you cannot ask the reason of reason, because reason is its own reason. Let us put the same thought in another way. When we demand the explanation of anything, what do we mean by explanation? What is it we want? Do we not mean that the thing appears to us irrational, and we want it shown that it is rational? When this is done, we say it is explained. Think, for example, of what is called the problem of evil. People often talk of it as the problem of the "origin of evil," as if what we want to know is, how evil began. But even if we knew this, it would not explain anything. Suppose that evil began because someone ate an apple. Does this make the matter any clearer? Do we feel that all our difficulties about the existence of evil are solved? No. This is [{241}] not what we want to know. The difficulty is that evil appears to us something irrational. The problem can only be solved by showing us that somehow, in spite of appearances, it is rational that evil should exist. Show us this, and evil is explained. Explanation of a thing, then, means showing that the thing is rational. Now we can ask that everything else in the world should be shown to be rational. But we cannot demand that the philosopher shall show that reason is rational. This is absurd. Reason is what is already absolutely rational. It is what explains itself. It is its own reason. It is a self-explanatory principle. This, then, must be the principle of which we are in search. The Absolute, we said, must be a self-explanatory principle, and there is only one such, namely, reason. The Absolute, therefore, is reason.

It was the greatness and glory of Plato to have seen this, and thereby to have become the founder of all true philosophy. For to say that the Absolute is concepts is the same as saying it is reason. It might seem, then, that Plato has satisfied the second canon of criticism. He takes as first principle a self-explanatory reality. But we cannot quite so quickly jump to this conclusion. After all, the mere word reason is not a key which will unlock to us the doors of the universe. Something more is necessary than the mere word. We must, in fact, be told what reason is. Now there are two senses in which we might ask the question, what reason is, one of which is legitimate, the other illegitimate. It is illegitimate to ask what reason is, in the sense of asking that it shall be explained to us in terms of something else, which is not reason. This would be [{242}] to give up our belief that reason is its own reason. It would be to seek the reason of reason in something which is not reason. It would be to admit that reason, in itself, is not rational. And this is absurd. But it is legitimate to ask, what reason is, meaning thereby, what is the content of reason. The content of reason, we have seen, is concepts. But what concepts? How are we to know whether any particular concept is part of the system of reason or not? Only, it is evident, by ascertaining whether it is a rational concept. If a concept is wholly rational, then it is a part of reason. If not, not. What we need, then, is a detailed account of all the concepts which reason contains, and a proof that each of these concepts is really rational. It is obvious that only in this way can we make a satisfactory beginning in philosophy. Before we can show that reason explains, that is, rationalizes the world, we must surely first show that reason itself is rational, or rather, to be more accurate, that our conception of reason is rational. There must not be any mere inexplicable facts, any mysteries, any dark places, in our notion of reason. It must be penetrated through and through by the light of reason. It must be absolutely transparent, crystalline. How can we hope to explain the world, if our very first principle itself contains irrationalities?

Each concept then must prove itself rational. And this means that it must be a necessary concept. A necessary proposition, we saw, is one, such as that two and two equal four, the opposite of which is unthinkable. So for Plato's Ideas to be really necessary it ought to be logically impossible for us to deny their [{243}] reality. It ought to be impossible to think the world at all without these concepts. To attempt to deny them ought to be shown to be self-contradictory. They ought to be so necessarily involved in reason that thought without them becomes impossible. Clearly this is the same as saying that the Ideas must not be mere ultimate inexplicable facts. Of such a fact we assert merely that it is so, but we cannot see any reason for it. To see a reason for it is the same as seeing its necessity, seeing not merely that it is so, but that it must be so.

Now Plato's Ideas are not of this necessary kind. There is, we are told, an Idea of whiteness. But why should there be such an Idea? It is a mere fact. It is not a necessity. We can think the world quite well without the Idea of whiteness. The world, so far as we can see, could get on perfectly well without either white objects or the Idea of whiteness. To deny its reality leads to no self-contradictions. Put it in another way. There are certainly white objects in the world. We demand that these, among other things, be explained. Plato tells us, by way of explanation, that there are white objects because there is an Idea of whiteness. But in that case why is there an Idea of whiteness? We cannot see. There is no reason. There is no necessity in this. The same thing applies to all the other Ideas. They are not rational concepts. They are not a part of the system of reason.