Plato's cosmogony is set forth in the Timaeus,1 which was translated into Latin by Cicero, and was, moreover, the only one of the dialogues that was known in the West in the Middle Ages. Both then, and earlier in Neoplatonism, it had more influence than anything else in Plato, which is curious, as it certainly contains more that is simply silly than is to be found in his other writings. As philosophy, it is unimportant, but historically it was so influential that it must be considered in some detail.
The place occupied by Socrates in the earlier dialogues is taken, in the Timaeus, by a Pythagorean, and the doctrines of that school are in the main adopted, including (up to a point) the view that number is the explanation of the world. There is first a summary of the first five books of the Republic, then the myth of Atlantis, which is said to have been an island off the Pillars of Hercules, larger than Libya and Asia put together. Then Timaeus, who is a Pythagorean astronomer, proceeds to tell the history of the world down to the creation of man. What he says is, in outline, as follows.
What is unchanging is apprehended by intelligence and reason; what is changing is apprehended by opinion. The world being sensible, cannot be eternal, and must have been created by God. Since God is good, He made the world after the pattern of the eternal; being without jealousy, He wanted everything as like Himself as possible. 'God desired that all things should be good, and nothing bad, as far as possible.' 'Finding the whole visible sphere not at rest, but moving in an irregular and disorderly fashion, out of disorder
he brought order.' (Thus it appears that Plato's God, unlike the Jewish and Christian God, did not create the world out of nothing, but rearranged pre-existing material.) He put intelligence in the soul, and the soul in the body. He made the world as a whole a living creature having soul and intelligence. There is only one world, not many, as various pre-Socratics had taught; there cannot be more than one, since it is a created copy designed to accord as closely as possible with the eternal original apprehended by God. The world in its entirety is one visible animal, comprehending within itself all other animals. It is a globe, because like is fairer than unlike, and only a globe is alike everywhere. It rotates, because circular motion is the most perfect; and since this is its only motion it needs no feet or hands.
The four elements, fire, air, water, and earth, each of which apparently is represented by a number, are in continued proportion, i.e. fire is to air as air is to water and as water is to earth. God used all the elements in making the world, and therefore it is perfect, and not liable to old age or disease. It is harmonized by proportion, which causes it to have the spirit of friendship, and therefore to be indissoluble except by God.
God made first the soul, then the body. The soul is compounded of the indivisible-unchangeable and the divisible-changeable; it is a third and intermediate kind of essence.
Here follows a Pythagorean account of the planets, leading to an explanation of the origin of time:
When the father and creator saw the creature which he had made moving and living, the created image of the eternal gods, he rejoiced, and in his joy determined to make the copy still more like the original; and as this was eternal, he sought to make the universe eternal, so far as might be. Now the nature of the ideal being was everlasting, but to bestow this attribute in its fulness upon a creature was impossible. Wherefore he resolved to have a moving image of eternity, and when he set in order the heaven, he made this image eternal but moving, according to number, while eternity itself rests in unity; and this image we call Time.2
Before this, there were no days or nights. Of the eternal essence we must not say that it was or will be; only is is correct. It is implied that of the 'moving image of eternity' it is correct to say that it was and will be.
Time and the heavens came into existence at the same instant. God made the sun so that animals could learn arithmetic—without the succession of days and nights, one supposes, we should not have thought of numbers. The
sight of day and night, months and years, has created knowledge of number and given us the conception of time, and hence came philosophy. This is the greatest boon we owe to sight.
There are (apart from the world as a whole) four kinds of animals: gods, birds, fishes, and land animals. The gods are mainly fire; the fixed stars are divine and eternal animals. The Creator told the gods that he could destroy them, but would not do so. He left it to them to make the mortal part of all other animals, after he had made the immortal and divine part. (This, like other passages about the gods in Plato, is perhaps not to be taken very seriously. At the beginning, Timaeus says he seeks only probability, and cannot be sure. Many details are obviously imaginative, and not meant literally.)
The Creator, Timaeus says, made one soul for each star. Souls have sensation, love, fear, and anger; if they overcome these, they live righteously, but if not, not. If a man lives well, he goes, after death, to live happily for ever in his star. But if he lives badly, he will, in the next life, be a woman; if he (or she) persists in evil-doing, he (or she) will become a brute, and go on through transmigrations until at last reason conquers. God put some souls on earth, some on the moon, some on other planets and stars, and left it to the gods to fashion their bodies.
There are two kinds of causes, those that are intelligent, and those that, being moved by others, are, in turn, compelled to move others. The former are endowed with mind, and are the workers of things fair and good, while the latter produce chance effects without order or design. Both sorts ought to be studied, for the creation is mixed, being made up of necessity and mind. (It will be observed that necessity is not subject to God's power.) Timaeus now proceeds to deal with the part contributed by necessity.3
Earth, air, fire, and water are not the first principles or letters or elements; they are not even syllables or first compounds. Fire, for instance, should not be called this, but such—that is to say, it is not a substance, but rather a state of substance. At this point, the question is raised: are intelligible essences only names? The answer turns, we are told, on whether mind is or is not the same thing as true opinion. If it is not, knowledge must be knowledge of essences, and therefore essences cannot be mere names. Now mind and true opinion certainly differ, for the one is implanted by instruction, the other by persuasion; one is accompanied by true reason, the other is not; all men share in true opinion, but mind is the attribute of the gods and of a very few among men.
This leads to a somewhat curious theory of space, as something intermediate between the world of essence and the world of transient sensible things.
There is one kind of being which is always the same, uncreated and indestructible, never receiving anything into itself from without, nor itself going out to any other, but invisible and imperceptible by any sense, and of which the contemplation is granted to intelligence only. And there is another nature of the same name with it, and like to it, perceived by sense, created, always in motion, becoming in place and again vanishing out of place, which is apprehended by opinion and sense. And there is a third nature, which is space, and is eternal, and admits not of destruction and provides a home for all created things, and is apprehended without the help of sense, by a kind of spurious reason, and is hardly real; which we beholding as in a dream, say of all existence that it must of necessity be in some place and occupy a space, but that what is neither in heaven nor on earth has no existence.
This is a very difficult passage, which I do not pretend to understand at all fully. The theory expressed must, I think, have arisen from reflection on geometry, which appeared to be a matter of pure reason, like arithmetic, and yet had to do with space, which was an aspect of the sensible world. In general it is fanciful to find analogies with later philosophers, but I cannot help thinking that Kant must have liked this view of space, as one having an affinity with his own.
The true elements of the material world, Timaeus says, are not earth, air, fire, and water, but two sorts of right-angled triangles, the one which is half a square and the one which is half an equilateral triangle. Originally everything was in confusion, and 'the various elements had different places before they were arranged so as to form the universe'. But then God fashioned them by form and number, and 'made them as far as possible the fairest and best, out of things which were not fair and good'. The above two sorts of triangles, we are told, are the most beautiful forms, and therefore God used them in constructing matter. By means of these two triangles, it is possible to construct four of the five regular solids, and each atom of one of the four elements is a regular solid. Atoms of earth are cubes; of fire, tetrahedra; of air, octahedra; and of water, icosahedra. (I shall come to the dodecahedron presently.)
The theory of the regular solids, which is set forth in the thirteenth book of Euclid, was, in Plato's day, a recent discovery; it was completed by Theaetetus, who appears as a very young man in the dialogue that bears his name. It was, according to tradition, he who first proved that there are only five kinds of regular solids, and discovered the octahedron and the icosahedron.4 The regular tetrahedron, octahedron, and icosahedron, have equilateral
triangles for their faces; the dodecahedron has regular pentagons, and cannot therefore be constructed out of Plato's two triangles. For this reason he does not use it in connection with the four elements.
As for the dodecahedron, Plato says only 'there was yet a fifth combination which God used in the delineation of the universe'. This is obscure, and suggests that the universe is a dodecahedron; but elsewhere it is said to be a sphere.5 The pentagram has always been prominent in magic, and apparently owes this position to the Pythagoreans, who called it 'Health' and used it as a symbol of recognition of members of the brotherhood:6 It seems that it owed its properties to the fact that the dodecahedron has pentagons for its faces, and is, in some sense, a symbol of the universe. This topic is attractive, but it is difficult to ascertain much that is definite about it.
After a discussion of sensation, Timaeus proceeds to explain the two souls in man, one immortal, the other mortal, one created by God, the other by the gods. The mortal soul is 'subject to terrible and irresistible affections—first of all, pleasure, the greatest incitement to evil; then pain, which deters from good; also rashness and fear, two foolish counsellors, anger hard to be appeased, and hope easily led astray; these they (the gods) mingled with irrational sense and with all-daring love according to necessary laws, and so framed men'.
The immortal soul is in the head, the mortal in the breast.
There is some curious physiology, as, that the purpose of the intestines is to prevent gluttony by keeping the food in, and then there is another account of transmigration. Cowardly or unrighteous men will, in the next life, be women. Innocent light-minded men, who think that astronomy can be learnt by looking at the stars without knowledge of mathematics, will become birds; those who have no philosophy will become wild land-animals; the very stupidest will become fishes.
The last paragraph of the dialogue sums it up:
We may now say that our discourse about the nature of the universe has an end. The world has received animals, mortal and immortal, and is fulfilled with them, and has become a visible animal containing the visible—the sensible God who is the image of the intellectual, the greatest, best, fairest, most perfect—the one only-begotten heaven.
It is difficult to know what to take seriously in the Timaeus, and what to regard as play of fancy. I think the account of the creation as bringing order out of chaos is to be taken quite seriously; so also is the proportion between
the four elements, and their relation to the regular solids and their constituent triangles. The accounts of time and space are obviously what Plato believes, and so is the view of the created world as a copy of an eternal archetype. The mixture of necessity and purpose in the world is a belief common to practically all Greeks, long antedating the rise of philosophy; Plato accepted it, and thus avoided the problem of evil, which troubles Christian theology. I think his world-animal is seriously meant. But the details about transmigration, and the part attributed to the gods, and other inessentials, are, I think, only put in to give a possible concreteness.
The whole dialogue, as I said before, deserves to be studied because of its great influence on ancient and medieval thought; and this influence is not confined to what is least fantastic.