The Absolute in Plato’s thought had not only life and intelligence but also creative activities; and the acts of creation consisted in imposing on the formless material principle the ideas which the Absolute comprehends in itself, or, as perhaps he would have preferred to say, in making the material principle partake of the appropriate idea. In the Cratylus he illustrates the relation of matter to the idea by the way in which the artisan makes a shuttle out of wood, always forming his material with reference to the true or ideal shuttle.[211] We may illustrate further by examples modelled on Plato’s own. Think for a moment of the potter and his clay. The clay is formless matter which the potter takes and places on the wheel, and there imposes upon the clay the idea of the pot which is in his own mind; so the pot acquires a real existence in so far as it partakes of or embodies the idea which exists in the potter’s mind. Or we may think of the sculptor and the shapeless block of marble. By imposing his idea upon the marble, by making the shapeless block embody his idea, the sculptor brings the statue into being. These illustrations, both Plato’s and my own, are of course misleading, for the wood, clay, and marble from which the several objects are made are far from being the negative substance which Plato would have us believe his material principle to be. But they may serve to suggest the way in which he conceived the varied world about us to come into its temporary existence.
Now to Plato’s mind the Absolute and the ideas are perfect; yet we know that the phenomenal world is imperfect, and imperfection is evil; therefore, he says, evil must be found in the negative substratum, since as we have already seen, this was regarded by Plato as in every way the opposite of the perfect ideas. This imperfection, inherent in the material principle, is the “necessity” of which he speaks in the Theaetetus as causing evils—the opposite of the good.[212] Evil, therefore, is eternal, but, as we have earlier learned, the individual may escape, if he will take the deliverance which philosophy offers him.
As I have said, the course of creation is explained through myth in the Timaeus and the Statesman.[213] In the former God is represented as creating first the gods of heaven which are the fixed stars and planets, from whom sprang the gods of popular mythology. The Creator had already conceived of creatures of the air, sea, and land; but these he did not himself create, for then they would have been on equality with the gods; he rather commissioned the gods to create man and the lower animals, while he furnished the divine part, the soul. Man’s soul therefore is of the same nature as the universal soul, but his body is material, made of the four elements of earth, air, fire, and water, and it is imperfect, being subject to the passions. In the Statesman Plato sets forth his theory of the development of man from an earlier stage to the present: the significant thing for us at the moment is his explanation of man’s falling away from virtue as due to the admixture of matter in him, that this fall was “inherent in the primal nature which was full of disorder.”
This, then, will at least suggest Plato’s view as to the origin of evil in the world. His language is that of myth, and it seems evident that he did not formulate his explanation perfectly even in his own mind. We shall best regard it as one of his guesses at truth. It is, of course, easy to find weaknesses in his thought on this question and to show that the explanation which he suggests is not satisfactory. But we shall do better to remember the difficulty of the problem and to recognize the value of his attempt to reach its solution.
The greatest service, however, which Plato did was to establish by means of his doctrine of ideas a rational relation between the invisible world of reason and the visible world of the senses; and by pointing out that the rational part of man’s soul is of the same substance as the ideas and therefore of the same substance as the Absolute, to give an intellectual basis to the doctrine of a natural striving on the part of man after the supreme Good. Hardly second to this was his service in the field of ethics, where he showed that man’s spiritual advance depends upon the constant curbing of the passions and the body. The greatness of his genius is shown by the fact that throughout antiquity the highest religious thought of paganism had its source in his work and was only a development of it. Before we have finished these lectures we shall gain some hints of his profound influence on Christianity.
Platonic philosophy by attributing to the ideas an existence apart from things, and conversely by denying all existence to anything but the ideas, had removed all reality to the supernatural world. It was inevitable that this view should be promptly attacked. The challenge came from Plato’s greatest pupil, Aristotle.
Aristotle, born at Stagira in Thrace about 384 b.c., by inheritance and early training had a strong bent toward natural science, since he was descended from a line of physicians who, according to Galen, taught anatomy by dissection. For twenty years he was the pupil and assistant of Plato in the Academy. After the death of his master he went to the court of Hermias, a prince of Mysia, and in 343 he was appointed tutor to the son of King Philip of Macedon, Alexander, then thirteen years of age. About 335 he opened a school in the Lyceum at Athens, where he taught for some thirteen years. Then, being accused of impiety after Alexander’s death, he withdrew to Chalcis in Euboea, as he said, that the Athenians might not sin a second time against philosophy; there he died about 322.
Into Aristotle’s encyclopedic knowledge and enormous scientific activities we may not now go; and indeed we need not dwell at very great length upon him, for his influence in religion was less potent than Plato’s through antiquity and the earlier Middle Ages. The chief cause of the elder philosopher’s greater influence is to be found in the fact that Plato’s thought centered on man, his morality, and his relation to God, while Aristotle was concerned primarily with the universe of which man was to him only a part; to Plato virtue was inseparably connected with religion, and was therefore something to be sought with fervent spirit as well as with cool reason; to Aristotle virtue was rather an intellectual matter, an even balance of the soul, that natural perfection of the whole organism on which the well-being and happiness of man depended—a state which was to be attained by right calculation, choice, and habit. So it came to pass that although Aristotle’s works on logic were continuously studied in one form or another, his great sway in many realms of human thought, including theology, began in the thirteenth century, when, learning first from Arabic scholars, later aided and stimulated by the Latin conquest of Constantinople in 1204, the western intellectual world eagerly studied his works anew. Then Albertus Magnus, St. Thomas Aquinas, and Roger Bacon raised him to the supreme position in philosophy and theology, so that he became for that age indeed “the master of those who know.”
Let us now consider some parts of his philosophy. He criticized Plato’s doctrine that ideas have an existence apart from things, and not unjustly charged that Plato had taken the universals, which we arrive at by abstraction, and had elevated these general concepts into eternal and immortal elements, claiming for them that they were anterior to the things of sense and alone had real existence. In his own philosophy he took a position fundamentally opposed to that of Plato, for he insisted that “ideas,” “forms” and the phenomenal world could not exist apart, for if they did, then we should be obliged to postulate a third world beyond them; that is to say, that if the idea of man, for example, had a substantial existence apart from individual men, then there would have to be an idea antecedent to both the idea of man and the individual men, the model of both, and this idea would be a “third man.” He further pointed out that men know the ideas only in the concrete objects, never apart from those objects of which they are the ideas, that the essence can never be separated from that of which it is the essence, since then both thing and essence would cease to exist. So he charged Plato with using meaningless poetic metaphors when he said that ideas, forms, existed apart from things. Reality to Aristotle was always in the individual object, itself an indissoluble union of matter and form. Of course he recognized that the human mind could abstract these two elements each from the other and could think of the matter and the form as separate, but he would not allow that these abstractions had substantial reality in the sense that they could ever exist by themselves.[214]