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7. Critical Estimate of Plato's Philosophy,
If we are to form a just estimate of the value of Plato's philosophy, we must not fritter away our criticism on the minor points, the external details, the mere outworks of the system. We must get at the heart and governing centre of it all. Amid the mass of thought which Plato has developed, in all departments of speculation, that which stands out as the central thesis of the whole system is the theory of Ideas. All else is but deduction from this. His physics, his ethics, his politics, his views upon art, all flow from this one governing theory. It is here then that we must look, alike for the merits and the defects of Plato's system.
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 adeus 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 thecontentof 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, thatour conceptionof 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.
But at this point, perhaps, a glimmer of hope dawns upon us. We ask the reason for these Ideas. Has not Plato asserted that the ultimate reason and ground of all the lower Ideas will be found in the supreme Idea of{244}the Good? Now if this is so, it means that the lower Ideas must find their necessity in the highest Idea. If we could see that the Idea of the Good necessarily involves the other Ideas, then these other Ideas would be really explained. In other words, we ought to be able to deduce all the other Ideas from this one Idea. It ought to be possible to show that, granted the Idea of the Good, all the other Ideas necessarily follow, that to assume the Good and deny the other Ideas would be self-contradictory and unthinkable. There are examples in Plato of the kind of deduction we require. For example, in the "Parmenides" he showed that the Idea of the one necessarily involves the Idea of the many, and vice versa. You cannot think the one without also thinking the many. This means that the many is deduced from the one, and the one from the many. Just in the same way, we ought to be able to deduce the Idea of whiteness from the Idea of the Good. But this is clearly not possible. You may analyse the Good as long as you like, you may turn it in every conceivable direction, but you cannot get whiteness out of it. The two Ideas do not involve each other. They are thinkable apart. It is quite possible to think the Good without thinking whiteness. And it is the same with all the other Ideas. None of them can be deduced from the Good.
And the reason of this is very obvious. Just as the lower Ideas contain only what is common among the things of a class, and exclude their differences, so the higher Ideas include what is common to the Ideas that come under them, but exclude what is not common. For example, the Idea of colour contains what white, blue, red, and green, have in common. But all colours{245}have not whiteness in common. Green, for example, is not white. Hence the Idea of colour excludes the Idea of whiteness, and it likewise excludes all the Ideas of the other particular colours. So too the highest Idea of all contains only what all the Ideas agree in, but all the rest falls outside it. Thus the Idea of whiteness is perfect in its kind. And as all Ideas are likewise perfect, the highest Idea is that in which they all agree, namely, perfection itself. But this means that the perfection of the Idea of whiteness is contained in the supreme Idea, but its specific character in which it differs from other Ideas is excluded. Its specific character is just its whiteness. Thus the perfection of whiteness is contained in the Good, but its whiteness is not. Consequently it is impossible to deduce whiteness from the Good, because the Good does not contain whiteness. You cannot get out of it what is not in it. When Plato deduced the many from the one, he did so only by showing that the One contains the many. He cannot deduce whiteness from goodness, because goodness does not contain whiteness.
The lower Ideas thus have not the character of necessity. They are mere facts. And the hope that we shall find their necessity in the supreme Idea fails. But suppose we waive this. Suppose we grant that there must be an Idea of whiteness, because there is an Idea of the Good. Then why is there an Idea of the Good? What is the necessity of that? We cannot see any necessity in it. What we said of the other Ideas applies with equal force to the highest Idea. The Good may be a necessary Idea, but Plato has not shown it.
Thus, though Plato named reason as the Absolute,{246}and though reason is a self-explanatory principle, his account of the detailed content of reason is so unsatisfactory that none of the concepts which he includes in it are really shown to be rational. His philosophy breaks down upon the second test as it did upon the first. He has neither explained the world from the Ideas, nor has he made the Ideas explain themselves.
There is one other defect in Plato's system which is of capital importance. There runs throughout it a confusion between the notions of reality and existence. To distinguish between existence and reality is an essential feature of all idealism. Even if we go back to the dim idealism of the Eleatics, we shall see this. Zeno, we saw, denied motion, multiplicity, and the world of sense. But he did not deny the existence of the world. That is an impossibility. Even if the world is delusion, the delusion exists. What he denied was the reality of existence. But if reality is not existence, what is it? It is Being, replied the Eleatics. But Being does not exist. Whatever exists is this or that particular sort of being. Being itself is not anywhere to be found. Thus the Eleatics first denied that existence is reality, and then that reality exists. They did not themselves draw this conclusion, but it is involved in their whole position.
With a fully developed idealism, like Plato's, this ought to be still clearer. And, in a sense, it is. The individual horse is not real. But it certainly exists. The universal horse is real. But it does not exist. But, upon this last point, Plato wavered and fell. He cannot resist the temptation to think of the absolute reality as existing. And consequently the Ideas are{247}not merely thought as the real universal in the world, but as having a separate existence in a world of their own. Plato must have realised what is, in truth, involved in his whole position, that the absolute reality has no existence. For he tells us that it is the universal, and not any particular individual thing. But everything that exists is an individual thing. Again, he tells us that the Idea is outside time. But whatever exists must exist at some time. Here then this central idealistic thought seems well fixed in Plato's mind. But when he goes on to speak of recollection and reincarnation, when he tells us that the soul before birth dwelt apart in the world of Ideas, to which after death it may hope to return, it is clear that Plato has forgotten his own philosophy, that he is now thinking of the Ideas as individual existences in a world of their own. This is a world of Ideas having a separate existence and place of its own. It is not this world. It is a world beyond. Thus the Platonic philosophy which began on a high level of idealistic thinking, proclaiming the sole reality of the universal, ends by turning the universal itself into nothing but an existent particular. It is the old old story of trying to form mental pictures of that which no picture is adequate to comprehend. Since all pictures are formed out of sensuous materials, and since we can form no picture of anything that is not an individual thing, to form a picture of the universal necessarily means thinking of it as just what it is not, an individual. So Plato commits the greatest sin that can be ascribed to a philosopher. He treats thought as a thing.
To sum up. Plato is the great founder of idealism, the initiator of all subsequent truths in philosophy.{248}But, as always with pioneers, his idealism is crude. It cannot explain the world; it cannot explain itself. It cannot even keep true to its own principles, because, having for the first time in history definitely enunciated the truth that reality is the universal, it straightway forgets its own creed and plunges back into a particularism which regards the Ideas as existent individuals. It was these defects which Aristotle set himself to rectify in a purer idealism, shorn of Plato's impurities.
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CHAPTER XIII
ARISTOTLE
1. Life, Writings, and general character of his Work.
Aristotle was born in 384 B.C. at Stagirus, a Grecian colony and seaport on the coast of Thrace. His father Nichomachus was court physician to King Amyntas of Macedonia, and from this began Aristotle's long association with the Macedonian Court, which considerably influenced his life and destinies. While he was still a boy his father died, and he was sent by his guardian, Proxenus, to Athens, the intellectual centre of the world, to complete his education. He was then aged seventeen. He joined the Academy and studied under Plato, attending the latter's lectures for a period of twenty years. In subsequent times, Aristotle's detractors, anxious to vilify his character, accused him of "ingratitude" to his master, Plato. It was said that Plato's old age had been embittered by dissensions in the school caused by the factious spirit of Aristotle. That there is no ground for attaching any blame to Aristotle for the troubles of Plato, which either did not exist or have been grossly exaggerated, is evident both from the facts within our knowledge and from the reference to Plato in Aristotle's works. It is not likely that, had Aristotle rendered himself genuinely objectionable, he could have remained for twenty years in{250}the Academy, and only left it upon the death of Plato. Moreover, although Aristotle in his works attacks the teaching of Plato with unsparing vigour, there is nowhere to be found in these attacks any suggestion of acrimony or personal rancour. On the contrary, he refers to himself as the friend of Plato, but a greater friend of the truth. The fact, in all probability, is that a man of such independent and original mind as Aristotle did not accord to Plato the kind of blind adoration and hero-worship which he may have received from the inferior intellects in the school. As is so often the case with young men of marked ability, the brilliant student may have suffered from the impatience and self-assertion of youth. There was certainly nothing worse.
While at the Academy Aristotle exhibited an unflagging spirit and unwearied zeal in the pursuit of knowledge in all its forms, a spirit which gave rise to nick-names and anecdotes, which probably contained as much truth, or as little, as most of the anecdotes which gather round remarkable characters. One of these stories was that he used a mechanical contrivance to wake him up whenever sleep threatened to put an end to his hours of study.
In 347 B.C. Plato died, and his nephew Speusippus was chosen as head of the Academy. Aristotle left Athens with his fellow-student Xenocrates, and together they repaired to the court of Hermeias, King of Atarneus, in Asia Minor. Hermeias, a man of low origin, but of high instincts and advanced education, had himself attended the lectures of Plato, and received the two young philosophers as welcome guests. Aristotle stayed three years at Atarneus, and, while there, married{251}Pythias, the niece of the King. In later life he was married a second time to one Herpyllis, who bore him a son, Nichomachus. At the end of three years Hermeias fell a victim to the treachery of the Persians, and Aristotle went to Mytilene. Here he remained for several years till he received an invitation from Philip of Macedonia to become the tutor of the young Alexander, afterwards conqueror of the world, then aged thirteen. Aristotle obeyed the summons, and for about five years superintended the education of Alexander. Both Philip and Alexander appear to have paid Aristotle high honour, and there were stories that he was supplied by the Macedonian court, not only with funds for the prosecution of learning, but even with thousands of slaves for the collection of specimens. These stories are probably false and certainly exaggerated. But there is no doubt that, in his scientific and philosophical enquiries, he was backed by the influence of the court, and could even perhaps have looked to that quarter for supplies, had it ever been necessary.
Upon the death of Philip, Alexander succeeded to the kingship. The period of his studies was now over, and he began to make preparations for his subsequent conquests. Aristotle's work being finished, he returned to Athens, which he had not visited since the death of Plato. He found the Platonic school flourishing under Xenocrates, and Platonism the dominant philosophy of Athens. He thereupon set up his own school at a place called the Lyceum. It was in connection with this that his followers became known, in after years, as the "peripatetics," a name which arose from Aristotle's habit of walking about as he discoursed. The period of{252}his residence in Athens lasted thirteen years, during which time he was occupied in the leadership of his school and in literary labours. This appears to have been the most fruitful period of his life. There is no doubt that all his most important writings were composed at this time. But at the end of this period his fortunes changed.
In B.C. 323 Alexander the Great died suddenly at Babylon in the midst of his triumphs. The Athenian Government was in the hands of a pro-Macedonian party. Upon the death of Alexander this party was overthrown, and a general reaction occurred against everything Macedonian. Alexander had been regarded in Greece much as Napoleon was regarded in Europe a century ago. He had insulted the free Greek cities. He had even sacked the city of Thebes. The whole of Greece lived in perpetual terror of invasion. Now that this fear was removed by his death, there was a general outburst of feeling against Macedonia. An anti-Macedonian party came into power. Now Aristotle had always been regarded as a representative and protege of the Macedonian court, although, as a matter of fact, he had recently fallen out of favour with the autocratic Alexander. A charge of impiety was trumped up against him. To escape prosecution he fled to Chalcis in Euboea, in order that, as he said, "the Athenians might not have another opportunity of sinning against philosophy as they had already done in the person of Socrates." He perhaps intended to return to Athens as soon as the storm had blown over. But in the first year of his residence at Chalcis he was overtaken by a sudden illness, and died at the age of sixty-three, in B.C. 322.
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Aristotle is said to have composed some four hundred books. Our astonishment at this productivity diminishes somewhat when we remember that what is here called a "book" is much the same as what we should call a chapter in a modern treatise. More than three-quarters of these writings have been lost. But, by good fortune, what remains to us is undoubtedly by far the most important part, and we have preserved in it a fairly complete account of the whole Aristotelian system in all its departments. Nearly all the writings, however, have come down to us in a mutilated state. This is especially the case with the "Metaphysics." This treatise is unfinished, and it was probably left unfinished by its author at his death. But apart from this, several of the books of the "Metaphysics" are undoubtedly spurious. Others apparently come in the wrong order. We end one book in the middle of a discussion, and when we begin the next we find ourselves in the middle of an entirely different subject. There are frequent repetitions, and parts of it read as if they were mere lecture notes. There are many interpolations. The same characteristics are to be observed in Aristotle's other writings, though in a less degree. It seems probable that they were not intended, in their present state, for publication. Final revision and finishing touches are lacking. In spite of these defects, the writings are voluminous and clear enough to enable us to trace out the whole of the main positions of Aristotle's thought.
We saw, in the case of Plato, that, as his literary activity lasted over a period of half a century, during which his philosophy was in constant development, it became important to trace this development in the{254}order of his Dialogues. The same thing is not true in the case of Aristotle. The whole of his writings, or rather those that have come down to us, seem to have been written during his last thirteen years, while he was at Athens, that is to say, after he had passed his fiftieth year. His system was then complete, mature, and fully developed. The question of the order in which they were written has no great importance. The result of critical investigations, however, is to show that he probably began with the various works upon logic, composed next the treatises upon physical science, next the ethical and political books, and lastly the "Metaphysics," which he left unfinished.
It must not be forgotten that Aristotle was not only a philosopher in the modern restricted sense of that term. He was a man of universal learning. There is no branch of knowledge which did not receive his attention, and upon which he was not the greatest expert of his time, except perhaps mathematics. So far was he from being only an abstract philosopher, that his natural tastes seem to have lain rather in the field of physical science than of abstract thought. But his design seems to have been to work over the entire field of knowledge, thoroughly to overhaul the sciences already in existence, rejecting what seemed false in the work of his predecessors, and invariably adding to the residue valuable developments and suggestions of his own. Where there was no science already in existence, his plan involved the foundation of new sciences wherever necessary, and he thus became the founder of at least two sciences, Logic and Zoology. He thus attained to a pre-eminence in all branches{255}of knowledge which would be impossible for a single man in modern times. His works include treatises upon Logic and Metaphysics, upon Ethics, Politics, and Art. He wrote a treatise upon the principles of Rhetoric, another upon Astronomy, under the title "On the Heavens," another upon Meteorology. Several of his treatises deal with the biology of animal life, in which he was intensely interested. They include books entitled "On the Parts of Animals," "On the Movements of Animals," "On the Origin of Animals," as well as his great treatise, "Researches on Animals," which contains an enormous mass of facts collected from every possible source. It is true that a large proportion of these facts have turned out to be fictions, but this was inevitable in the infancy of science. It has been calculated that Aristotle shows himself acquainted with about five hundred different species of living beings, though they are not, of course, classified by him in the modern way. With these books upon animals he founded the science of Zoology, for no one before his day had made any special study of the subject.
It has been said that everyone has either an Aristotelian or a Platonic type of mind. As this implies that Aristotle and Plato are opposites, it is considerably less than a half truth. No genuine understanding of Aristotle can endorse the opinion that his philosophical system was the opposite of Plato's. It would be truer to say that Aristotle was the greatest of all Platonists, since his system is still founded upon the Idea, and is an attempt to found an idealism free from the defects of Plato's system. It is in fact a development of Platonism. What is the cause then of the popular notion that{256}Aristotle was the opposite of Plato? Now the fact is that theywereopposites in many important respects. But there was a fundamental agreement between them which lies deeper than the differences. The differences are largely superficial, the agreement is deep-seated. Hence it is the differences that are most obvious, and it was the differences, too, which were most obvious to Aristotle himself. The popular opinion arises largely from the fact that Aristotle never loses an opportunity of attacking the Platonic theory of Ideas. He is continually at pains to emphasize the difference between himself and Plato, but says nothing of the agreement. But no man is a judge of his own deeper relations to his predecessors and contemporaries. It is only in after years, when the hubbub of controversy has settled down into the silence of the past, that the historian can see the true perspective, and can penetrate the relations of each great man to the time in which he lived. Plato was the founder of idealism, and his idealism was in many respects crude and untenable. It was the special mission of Aristotle to clear away these crudities, and so develop Platonism into a tenable philosophy. And it was natural that he should emphasize the crudities, which he had to fight so hard to overcome, rather than that substratum of truth which Plato had already developed, and which therefore required no special treatment at his hands. It was the differences between himself and his predecessor which were most obvious to him, and it was inevitable that he should adopt a thoroughly polemical attitude towards his master.
But if the agreement was more deep-seated than the differences, and lay in the recognition of the Idea as the{257}absolute foundation of the world, the differences were none the less very striking. In the first place, Aristotle loved facts. What he wanted was always definite scientific knowledge. Plato, on the other hand, had no love of facts and no gift for physical enquiries. And what disgusted Aristotle about the system of Plato was the contempt which it poured upon the world of sense. To depreciate objects of sense, and to proclaim the knowledge of them valueless, was a fundamental characteristic of all Plato's thinking. But the world of sense is the world of facts, and Aristotle was deeply interested in facts. No matter in what branch of knowledge, any fact was received by Aristotle with enthusiasm. To Plato it appeared of no interest what the habits of some obscure animal might be. That alone which should be pursued is the knowledge of the Idea. And he went so far as to deny that knowledge of the sense-world could properly be described as knowledge at all. But the habits of animals appeared to Aristotle a matter worthy of investigation for its own sake. Francis Bacon in his "Novum Organum" has many contemptuous references to Aristotle. And the gist of them all is that Aristotle had no regard for facts, but theorized a priori out of his head, and that instead of patiently investigating the facts of nature, he decided, upon so-called "rational" grounds, what nature ought to do, and squared the facts with his theories.
It was natural for Bacon to be unjust to him. He, with the other thinkers of his time, was engaged upon an uphill fight against scholasticism, then dominant, which claimed to represent the true teaching of Aristotle. And it was true that the schoolmen theorized a priori,{258}and ignored facts, or, what was worse, appealed to the writings of Aristotle to decide questions of fact which should have been decided by an appeal to nature. And Bacon not unnaturally confounded Aristotle with these modern Aristotelians, and attributed to him the faults that were really theirs. But no man was ever keener on facts than Aristotle as is proved by his treatises upon animals, which contain evidences of astonishing patience and laborious work in the collection of facts. It is true, however, that even in the domain of facts, Aristotle, like all the ancients, was guilty of introducinga priorireasonings when they were quite out of place. Thus he does not scruple to argue that the stars must move in circles because the circle is the perfect figure. And numerous similar instances could be quoted. But it was inevitable that, with science in its swaddling clothes, without the aid of any instruments, or of any body of previously ascertained truths, Aristotle should fall into these snares. He well understood the fundamental necessity of all natural sciences for a laborious investigation of facts, but, when this was impossible, he used the only means in his power, his reason.
Secondly, in spite of Plato's rationalism, he had allowed to myths and poetry a large share in the development of his thoughts, and had even exhibited a distinct tendency towards mysticism. Here again what Aristotle wanted was definite knowledge. It pained him to see poetic metaphors substituted for rational explanation. And this accounts for the third main difference between Plato and Aristotle, the marked contrast in their prose styles. Plato was a master-artist in words. Aristotle cared nothing for the ornaments and beauties of style.{259}He harshly excludes them from his work. What alone he is intent upon is the meaning, the truth that the words express. He is too much in earnest with philosophy to lose himself in a haze of beautiful words, or to be put off with metaphors instead of reasons. His style is even harsh, abrupt, and ugly. But what it loses in beauty it gains in clearness of conception. For every thought or shade of thought which it is desired to express there is an accurate term. If no term in common use will express the thought, Aristotle coins one. Hence he is one of the greatest terminologists that ever lived. He adapted or invented an enormous number of terms. He may be not unjustly regarded as the founder of philosophical language, as the inventor of a vocabulary of technical terms. Many of the terms used to this day to express man's most abstract thoughts, were invented or introduced by Aristotle. It must not be supposed that Aristotle wrote in a rigidly scientific style because he had no aesthetic sense. The very contrary is the case. His treatise on art shows him by far the best critic of the ancient world, and in his appreciation and estimation of the beautiful he far excels Plato. But he saw that art and science have each their own sphere, and that it is fatal to confuse the two. Nothing is so damaging to art as to be made the mere vehicle of reasoning. Nothing is so damaging to philosophy as to allow itself to be governed by poetry. If we want beauty, we must follow the path of art. But if we desire truth, we must stick close to reason.
Aristotle's system falls most easily into the fivefold division of logic, metaphysics, physics, ethics, and aesthetics.
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2. Logic.
Not much need be said under this head, because whoever knows the common logic of the text-books knows the logic of Aristotle. Of the two branches of reasoning, deductive and inductive, Aristotle clearly recognizes the latter. And many of his observations upon induction are acute and penetrating. But he has not reduced induction to a science. He has not laid bare the fundamental canons of inductive thought. This was a work not performed until comparatively modern times. His name therefore is more especially associated with deductive logic, of which he was the founder. He not only founded the science, but practically completed it. What we now know as "formal logic," what is to this day contained in all text-books, taught in all schools and universities, is, in all its essentials, nothing more than the logic of Aristotle. His writings upon the subject include the treatment of the well-known laws of thought, the doctrine of the ten categories, the five predicables, the doctrines of terms, of propositions, of syllogisms, and of the reduction of the other figures to the first figure of the syllogism. And these heads might well form the list of contents of a modern work on formal logic. In only two respects has any advance been made upon Aristotle by subsequent logicians. The fourth figure of the syllogism is not recognized by Aristotle; and he dealt only with categorical syllogisms, and does not treat conditional syllogisms. But whether or not the fourth figure of the syllogism has any value is still a matter open to dispute. And though the doctrine of conditional syllogisms is important, it is not essential, because all conditional syllogisms can be reduced to categorical{261}syllogisms. The categorical syllogism is the fundamental type of reasoning, to which every other form of deduction can be reduced. As for the rest of the huge treatises on formal logic which some moderns have produced, the supposed additions are nothing but wearisome, endless, useless, nauseating, academic distinctions and refinements, which are much better forgotten than remembered. Aristotle's logic contains therefore all that is essential to the subject. The only ground on which it can be attacked is its wholly empirical procedure. But that is another story. As a collection, arrangement, and analysis of the facts of reason, it is to all intents and purposes finality achieved at one stroke.
3. Metaphysics.
The treatise now known as the "Metaphysics" of Aristotle did not originally bear that name. Aristotle's name for this subject is "first philosophy," by which he means the knowledge of the first, highest, or most general principles of the universe. All other branches of knowledge are subordinate to this science, not because they are inferior in value, but because they are lower in logical sequence as dealing with principles less universal in their scope. Thus all the special sciences deal with one or another particular sphere of being, but the "first philosophy" has for its subject being as such, "being so far forth as it is being." It studies, not the characteristics of this or that kind of being, but the principles which are equally true of all being. The laws of Zoology apply only to animals, but the principles of the "first philosophy" apply to everything. The name "metaphysics" came into use only half a century B.C., when{262}Andronicus published a complete edition of Aristotle's known works. In this edition the treatise on "first philosophy" was placed after the "physics," and "metaphysics" signifies simply "after physics." The derivation of the word thus appears to be merely accidental and adventitious. Whether it was also in any way intended to signify that the subject is "beyond physics," that is, deals with what transcends physical existence, seems doubtful.
Aristotle's metaphysical theory grows naturally out of his polemic against Plato's theory of Ideas, because his own system was in effect simply an attempt to overcome the defects which he found in Plato. The main heads of this polemic are the following:--
(1) Plato's Ideas do not explain the existence of things. To explain why the world is here is after all the main problem of philosophy, and Plato's theory fails to do this. Even admitting that, say, the Idea of whiteness exists, we cannot see how it produces white objects.
(2) Plato has not explained the relation of Ideas to things. Things, we are told, are "copies" of Ideas, and "participate" in them. But how are we to understand this "participation"? In using such phrases, says Aristotle, Plato is giving no real account of the relationship, but is merely "uttering poetic metaphors."
(3) Even if the existence of things is explained by the Ideas, their motion is not. Suppose that the Idea of whiteness produces white things, the Idea of beauty beautiful things, and so on, yet, since the Ideas themselves are immutable and motionless, so will be the world which is their copy. Thus the universe would be{263}absolutely static, like Coleridge's "painted ship upon a painted ocean." But the world, on the contrary, is a world of change, motion, life, becoming. Plato makes no attempt to explain the unceasing becoming of things. Even if the Idea of whiteness explains white objects, yet why do these objects arise, develop, decay, and cease to exist? To explain this there must be some principle of motion in the Ideas themselves. But there is not. They are immovable and lifeless.
(4) The world consists of a multitude of things, and it is the business of philosophy to explain why they exist. By way of explanation Plato merely assumes the existence of another multitude of things, the Ideas. But the only effect of this is to double the number of things to be explained. How does it help thus to duplicate everything? And Aristotle likens Plato to a man who, being unable to count with a small number, fancies that, if he doubles the number, he will find it easier to count.
(5) The Ideas are supposed to be non-sensuous, but they are, in fact, sensuous. Plato thought that a non-sensuous principle must be sought in order to explain the world of sense. But not being able to find any such principle, he merely took the objects of sense over again and called them non-sensuous. But there is, in fact, no difference between the horse and the Idea of the horse, between the man and the Idea of the man, except a useless and meaningless "in-itself" or "in-general" attached to each object of sense to make it appear something different. The Ideas are nothing but hypostatized things of sense, and Aristotle likens them to the anthropomorphic gods of the popular religion. "As{264}these," he says, "are nothing but deified men, so the Ideas are nothing but eternalized things of nature." Things are said to be copies of Ideas, but in fact the Ideas are only copies of things.
(6) Next comes the argument of the "third man," so called by Aristotle from the illustration by which he explained it. Ideas are assumed in order to explain what is common to many objects. Wherever there is a common element there must be an Idea. Thus there is a common element in all men, and therefore there is an Idea of man. But there is also an element common to the individual man and to the Idea of man. There must, therefore, be a further Idea, the "third man," to explain this. And between this further Idea and the individual man there must be yet another Idea to explain what they have in common, and so onad 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{271}existence for granted, and seeks to trace their history and their relations to each other. Therefore it does not require formal causes. It seeks to work out the mechanical view of the universe, and therefore considers only mechanical causes. But Aristotle's theory, as being philosophy rather than science, includes both the principles of mechanism and teleology.
It was not Aristotle's habit to propound his theories as if they were something absolutely new, sprung for the first time out of his own brain. In attacking any problem, his custom was to begin by enumerating current and past opinions, to criticise them, to reject what was valueless in them, to retain the residue of truth, and to add to it his own suggestions and original ideas. The resultant of this process was his own theory, which he thus represented, not as absolutely new, but as a development of the views of his predecessors. This course he follows also in the present instance. The first book of the "Metaphysics" is a history of all previous philosophy, from Thales to Plato, undertaken with the object of investigating how far the four causes had been recognized by his predecessors. The material cause, he says, had been recognized from the first. The Ionics believed in this and no other cause. They sought to explain everything by matter, though they differed among themselves as to the nature of the material cause, Thales describing it as water, Anaximenes as air. Later philosophers also gave different accounts of it, Heracleitus thinking it was fire, Empedocles the four elements, Anaxagoras an indefinite number of kinds of matter. But the point is that they all recognized the necessity for a material cause of some sort to explain the universe.
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The earliest thinkers, then, the Ionics, assumed only this one cause. But as thought advanced, says Aristotle, and other philosophers came upon the scene, "the thing itself guided them." It was seen that a second cause was necessary to explain the motion and becoming of things. For matter itself does not produce its motion. Wood is not the cause of its becoming a bed, nor is brass the cause of its becoming a statue. Hence arose the idea of the efficient cause. The Eleatics did not recognize it, for they denied motion, and for them, therefore, no cause of motion could be assumed. But Parmenides, Aristotle thinks, wavered on this point, somehow allowing vaguely the existence of a second cause, which he denominated the hot and the cold. The reference is, of course, to the second part of the poem of Parmenides. Other philosophers clearly assumed an efficient cause, for they thought that one element, for example, fire, is more active, that is, more productive of motion, than others. Empedocles certainly attained to the idea of an efficient cause, for he named as moving forces, harmony and discord, love and hate. Anaxagoras also, used Nous as a moving force.
Formal causes had, perhaps, been recognized by the Pythagoreans, for numbers are forms. But they straightway degraded the formal cause to the level of a material cause by declaring that number is the stuff or matter of which things are made. Plato alone clearly saw the necessity for the formal cause, for formal causes are, as we have seen, the same as Plato's Ideas. But Plato's philosophy contains only two of the four causes, namely the material and the formal, for Plato made all things out of matter and the Ideas. Since the Ideas have in them{273}no principle of motion, Plato's system contains no efficient cause. As for final causes, Plato had indeed the vague idea that everything is for the sake of the Good, but he makes no use of this conception and does not develop it. Final causes were introduced into philosophy by Anaxagoras, whose doctrine of the world forming mind was assumed to explain the design and purpose which the universe exhibits. But as his system developed he forgot about this, and used the Nous merely as a piece of mechanism to explain motion, thus letting it sink into nothing more than an efficient cause.
In the result, Aristotle finds that all four causes have been recognized in greater or lesser degrees by his predecessors, and this, in his opinion, greatly reinforces his own doctrine. But whereas material and efficient causes have been clearly understood, his predecessors had only vaguely foreshadowed and dimly perceived the value of formal and final causes.
The next step in Aristotle's metaphysics is to reduce these four principles to two, which he calls matter and form. This reduction takes place by showing that formal cause, efficient cause, and final cause, all melt into the single conception of form. In the first place, the formal cause and the final cause are the same. For the formal cause is the essence, the concept, the Idea, of the thing. Now the final cause, or the end, is simply the realisation of the Idea of the thing in actuality. What the thing aims at is the definite expression of its form. It thus aims at its form. Its end, final cause, is thus the same as its formal cause. Secondly, the efficient cause is the same as the final cause. For the efficient cause is the cause of becoming. The final cause is the end of{274}the becoming, it is what it becomes. And, in Aristotle's opinion, what causes the becoming is just that it aims at the end. The striving of all things is towards the end, and exists because of the end. The end is thus itself the cause of becoming or motion. That is to say, the final cause is the real efficient cause. We may see this better by an example. The end or final cause of the acorn is the oak. And it is the oak which is the cause of the acorn's growth, which consists essentially in a movement by which the acorn is drawn towards its end, the oak. We may see this even more definitely in the case of human productions, because here the striving towards an end is conscious, whereas in nature it is unconscious or instinctive. The efficient cause of the statue is the sculptor. It is he that moves the brass. But what moves the sculptor, and causes him to act upon the brass, is the idea of the completed statue in his mind. The idea of the end, the final cause, is thus the real ultimate cause of the movement. Only, in the case of human production, the idea of the end is actually present in the sculptor's mind as a motive. In nature there is no mind in which the end is conscious of itself, but nevertheless nature moves towards the end, and the end is the cause of the movement. Thus the three causes named all melt into a single notion, which Aristotle calls the form of the thing. And this leaves only the material cause unreduced to any other. So we are left with the single antithesis of matter and form.
Now as matter and form are the fundamental categories of Aristotle's philosophy, by means of which he seeks to explain the entire universe, it is essential that we should thoroughly understand their characteristics.{275}First of all, matter and form are inseparable. We think of them as separate in order to understand them clearly. And this is quite right, because they are opposite principles, and therefore they are separable in thought. But they are never separable in fact. There is no such thing as form without matter, or matter without form. Every existent thing, that is, every individual object, is a compound of matter and form. We may compare them in this respect to the material and the shape of a thing, though we must be careful not to think that form is merely shape. Geometry considers shapes as if they existed by themselves. But, in fact, we know that there are no such things as squares, circles, and triangles. There are only square objects, circular objects, etc. And as there are no shapes without objects, so there are no objects without shapes. We talk of things being "shapeless," but this only means that their shape is irregular or unusual. Some shape an object must have. Yet, though shape and matter are inseparable in fact, they are opposite principles, and are separable in thought. Geometry is quite right to treat shapes as if they existed by themselves, but it is nevertheless dealing with mere abstractions. Just in the same way, matter and form are never apart, and to think of form by itself or matter by itself is a mere abstraction. No such thing exists. In fact, to imagine that forms can exist by themselves was just the mistake of which, as we have seen, Aristotle accuses Plato. For the form is the Idea, and Plato imagined that Ideas exist in a world of their own.
From this, too, we can see that the form is the universal, the matter the particular. For the form is the Idea, and the Idea is the universal. To say that form and{276}matter cannot exist apart is thus the same as saying that the universal only exists in the particular, which, as we have seen, is the fundamental note of Aristotle's philosophy. But if we thus identify matter with the particular element in things, we must be careful that we do not confuse the particular with the individual. We often use these two words as practically synonymous, and there is no harm in this, but here we must be careful to separate them. For every individual is, according to Aristotle, a compound of matter and form, of the particular and the universal. And when we say that matter is the particular, we mean, not that it is such a compound, but that it is the absolutely particular which has no universal in it. But the absolutely particular and isolated does not exist. A piece of gold, for instance, only exists by virtue of its properties, yellowness, heaviness, etc., and these qualities are just what it has in common with other things. So that the particular, as such, has no existence, but this is only the same as saying, what we have already said, that matter has no existence apart from form.
A very natural mistake would be to suppose that by matter Aristotle meant the same as we do, namely, physical substance, such as wood or iron, and that by form he meant simply shape. Now although there is a kinship in the ideas, these two pairs of ideas are far from identical. Let us begin with matter. Our ordinary idea of matter as physical substance is an absolute conception. That is to say, a thing which we call material is absolutely, once and for all, matter. It is not material from one point of view, and immaterial from another. In every possible relation it is, and{277}remains, matter. Nor does it in process of time cease to be matter. Brass never becomes anything but matter. No doubt there are in nature changes of one sort of matter into another, for example, radium into helium. And for all we know, brass may become lead. But even so, it does not cease to be matter. But Aristotle's conception of matter is a relative conception. Matter and form are fluid. They flow into one another. The same thing, from one point of view, is matter, from another, form. In all change, matter is that which becomes, that upon which the change is wrought. That is form towards which the change operates. What becomes is matter. What it becomes is form. Thus wood is matter if considered in relation to the bed. For it is what becomes the bed. But wood is form if considered in relation to the growing plant. For it is what the plant becomes. The oak is the form of the acorn, but it is the matter of the oak furniture.
That matter and form are relative terms shows, too, that the form cannot be merely the shape. For what is form in one aspect is matter in another. But shape is never anything but shape. No doubt the shape is part of the form, for the form in fact includes all the qualities of the thing. But the shape is quite an unimportant part of the form. For form includes organization, the relation of part to part, and the subordination of all parts to the whole. The form is the sum of the internal and external relations, the ideal framework, so to speak, into which the thing is moulded. Form also includes function. For it includes the final cause. Now the function of a thing is just what the thing is for. And what it is for is the same as its end, or final cause.{278}Therefore function is included in form. For example, the function of a hand, its power of gripping, is part of its form. And therefore, if it loses its function by being cut off from the arm, it likewise loses its form. Even the dead hand, of course, has some form, for every individual object is a compound of matter and form. But it has lost the highest part of its form, and relatively to the living hand it is mere matter, although, relatively to the flesh and bones of which it is composed, it is still form. Clearly, then, form is not merely shape. For the hand cut off does not lose its shape.
The form includes all the qualities of the thing. The matter is what has the qualities. For the qualities are all universals. A piece of gold is yellow, and this means simply that it has this in common with other pieces of gold, and other yellow objects. To say that anything has a quality is immediately to place it in a class. And what the class has in common is a universal. A thing without qualities cannot exist, nor qualities without a thing. And this is the same as saying that form and matter cannot exist separately.
The matter, then, is the absolutely formless. It is the substratum which underlies everything. It has, in itself, no character. It is absolutely featureless, indefinite, without any quality. Whatever gives a thing definiteness, character, quality, whatever makes it a this or that, is its form. Consequently, there are no differences within matter. One thing can only differ from another by having different qualities. And as matter has no qualities, it has no difference. And this in itself shows that the Aristotelian notion of matter is not the same as our notion of physical substance. For, according{279}to our modern usage, one kind of matter differs from another, as brass from iron. But this is a difference of quality, and for Aristotle all quality is part of the form. So in his view the difference of brass from iron is not a difference of matter, but a difference of form. Consequently, matter may become anything, according to the form impressed upon it. It is thus the possibility of everything, though it is actually nothing. It only becomes something by the acquisition of form. And this leads directly to a most important Aristotelian antithesis, that between potentiality and actuality. Potentiality is the same as matter, actuality as form. For matter is potentially everything. It may become everything. It is not actually anything. It is a mere potentiality, or capacity of becoming something. But whatever gives it definiteness as a this or that, whatever makes it an actual thing, is its form. Thus the actuality of a thing is simply its form.
Aristotle claims, by means of the antithesis of potentiality and actuality, to have solved the ancient problem of becoming, a riddle, propounded by the Eleatics, which had never ceased to trouble Greek thinkers. How is becoming possible? For being to pass into being is not becoming, for it involves no change, and for not-being to pass into being is impossible, since something cannot come out of nothing. For Aristotle, the sharp line drawn between not-being and being does not exist. For these absolute terms he substitutes the relative terms potentiality and actuality, which shade off into each other. Potentiality in his philosophy takes the place of not-being in previous systems. It solves the riddle because it is not an absolute not-being. It is{280}not-being inasmuch as it is actually nothing, but it is being because it is potential being. Becoming, therefore, does not involve the impossible leap from nothing to something. It involves the transition from potential to actual being. All change, all motion, is thus the passage of potentiality into actuality, of matter into form.