A Beginner's History of Philosophy, Vol. 1: Ancient and Mediæval Philosophy

by Herbert Ernest Cushman

Man		Rational nature ＝ reason
		Irrational nature		Noble ＝ will
				Ignoble ＝ sensuous appetites

This is the celebrated doctrine of the “three parts” of the soul. Are they three parts or three functions of the soul? Plato is not clear as to this point. He sometimes speaks of them as three divisions, and treats them as separable in such a way that only the reason is immortal and the other two parts are mortal. Again, hespeaks of the soul as a unity, which carries with it in the next life all three functions. In this latter meaning the three parts are three natures or three different degrees of worth of the unitary soul.

Plato’s Doctrine of Immortality. Beginning with this conception of the dual nature of the human soul, Plato reasons both backward and forward from it: backward to its pre-existence, and forward from its post-existence,—its existence after death. In the Phædo, Plato has put into the mouth of what has become his Platonized Socrates his final thought concerning the relation of this present life to its past and its future. It is plainly the doctrine of the transmigration of souls, which he got from the Pythagoreans. The soul has a reality that is imperishable, and the soul is rewarded or punished for its conduct in one existence by the kind of existence into which it is metamorphosed. In prison, on that fatal day when he drank the poison, Socrates explained to those around him why he was so cheerful at the thought of death. Is not our present existence a kind of death? Is not the soul in the present life deterred from true knowledge by the trammels of the bodily desires? The true philosopher is he who turns away from his body’s passions,—dies to them, and tries to live the reality of the world of Ideas. We shall have full knowledge when we pass beyond the grave and then we shall be rewarded, if we have striven truly. But at present our body hampers and misleads us with its perceptions of changing mortality around us, and with its transitory desires. This life itself is the reward or punishment for our conduct in our preceding state.

1. The Immortality of Pre-existence. What proof does Plato offer for our existence before this life? TheIdeas, these testimonies of reality, form a part of the human soul. They are eternal, and have not been created by the soul. Knowledge is not the origination of a new truth, but is the recognition of Ideas, whose presence the mind merely records. Greek psychology never got much farther than this. The modern psychological conception of the soul as a dynamic something, which creates its own content, was quite foreign to the Greeks. To Plato, as to all other Greeks, the soul is as passive as the wax that receives the impress of the seal. All Greek psychology was under this general limitation: all ideas must be “given” to the soul. Therefore if the Ideas are not “given” by perception, because perception is of the changing; if nevertheless the soul finds itself in possession of the Ideas on the occasion of perception; if the soul did not create the Ideas, because the soul is by nature passive; the logical and only conclusion is that the soul was already in possession of the Ideas in a pre-existent state. Pre-existence is the only way of accounting for the full-born knowledge of the soul, and it is interesting to note how important was the pre-existent state to the imagination of the ancient world.

Plato therefore advanced the doctrine of reminiscence, or as he called it, Anamnesis, as proof of our pre-existence. Knowledge is recollection. The Ideas have always been present in the mind, and when we recognize them we have knowledge. The Ideas have no past or future, but they always exist. It is the mind that undergoes awakening—an awakening to their existence in itself. When the mind sees the objects of physical nature, it awakens in painful astonishment at the contrast between the sense world and the Ideas ofits native world of immateriality. In a mythical representation in the Phædrus, Plato supposes that before the present life our souls have beheld the pure Ideas in their full reality, that the Ideas had been forgotten in our birth into the present life, but that the perception of similar corporeal things calls the soul back to the Ideas themselves. Then the “Eros” is awakened—the native philosophical impulse or inborn love for the Ideas, by which the soul is raised again to the knowledge of that true reality. Only the pure Ideas themselves will satisfy this longing; the embodiment of the Ideas in art or personalities is not adequate. The Eros ties us to the Ideas. God does not have this longing, for He fully knows the Good. The ignorant man does not have this longing, for he does not suspect the existence of the Ideas in himself. The Eros is the homesickness that the lover of the truth feels.

Our birth is but a sleep and a forgetting,

The soul that rises in us, our life’s star,

Hath had elsewhere its setting,

And cometh from afar;

Not in entire forgetfulness,