The orrery or picture of the heavens given in the Republic differs in its mode of representation from the circles of the same and of the other in the “Timaeus.” In both the fixed stars are distinguished from the planets, and they move in orbits without them, although in an opposite direction: in the Republic as in the “Timaeus” (40 B) they are all moving round the axis of the world. But we are not certain that in the former they are moving round the earth. No distinct mention is made in the Republic of the circles of the same and other; although both in the “Timaeus” and in the Republic the motion of the fixed stars is supposed to coincide with the motion of the whole. The relative thickness of the rims is perhaps designed to express the relative distances of the planets. Plato probably intended to represent the earth, from which Er and his companions are viewing the heavens, as stationary in place; but whether or not herself revolving, unless this is implied in the revolution of the axis, is uncertain (compare “Timaeus”). The spectator may be supposed to look at the heavenly bodies, either from above or below. The earth is a sort of earth and heaven in one, like the heaven of the “Phaedrus,” on the back of which the spectator goes out to take a peep at the stars and is borne round in the revolution. There is no distinction between the equator and the ecliptic. But Plato is no doubt led to imagine that the planets have an opposite motion to that of the fixed stars, in order to account for their appearances in the heavens. In the description of the meadow, and the retribution of the good and evil after death, there are traces of Homer.
The description of the axis as a spindle, and of the heavenly bodies as forming a whole, partly arises out of the attempt to connect the motions of the heavenly bodies with the mythological image of the web, or weaving of the Fates. The giving of the lots, the weaving of them, and the making of them irreversible, which are ascribed to the three Fates—Lachesis, Clotho, Atropos, are obviously derived from their names. The element of chance in human life is indicated by the order of the lots. But chance, however adverse, may be overcome by the wisdom of man, if he knows how to choose aright; there is a worse enemy to man than chance; this enemy is himself. He who was moderately fortunate in the number of the lot—even the very last comer—might have a good life if he chose with wisdom. And as Plato does not like to make an assertion which is unproven, he more than confirms this statement a few sentences afterwards by the example of Odysseus, who chose last. But the virtue which is founded on habit is not sufficient to enable a man to choose; he must add to virtue knowledge, if he is to act rightly when placed in new circumstances. The routine of good actions and good habits is an inferior sort of goodness; and, as Coleridge says, “Common sense is intolerable which is not based on metaphysics,” so Plato would have said, “Habit is worthless which is not based upon philosophy.”
The freedom of the will to refuse the evil and to choose the good is distinctly asserted. “Virtue is free, and as a man honours or dishonours her he will have more or less of her.” The life of man is “rounded” by necessity; there are circumstances prior to birth which affect him (compare “Politicus” 273 B). But within the walls of necessity there is an open space in which he is his own master, and can study for himself the effects which the variously compounded gifts of nature or fortune have upon the soul, and act accordingly. All men cannot have the first choice in everything. But the lot of all men is good enough, if they choose wisely and will live diligently.
The verisimilitude which is given to the pilgrimage of a thousand years, by the intimation that Ardiaeus had lived a thousand years before; the coincidence of Er coming to life on the twelfth day after he was supposed to have been dead with the seven days
