So far as the soul is a mean between the spiritual and corporeal, may we connect the Phædon’s proofs of its immortality with the psychological view now before us. The common thought of these arguments is that the soul, in its capacity for thinking, participates in the reason, and being thus of an opposite nature to, and uncontrolled by the corporeal, it may have an independent existence. The arguments are wholly analytical, and possess no valid and universal proof; they proceed entirely upon a _petitio principii_, they are derived partly from mythical philosophemes, and manifest not only an obscure conception of the soul, but of its relations to the body and the reason, and, so far as the relation of the soul to the ideal world is in view, they furnish in the best case only some proof for the immortality of him who has raised his soul to a pure spirit, _i. e._ the immortality of the philosopher. Plato was not himself deceived as to the theoretical insufficiency of his arguments. Their number would show this, and, besides, he expressly calls them proofs which amount to only human probability, and furnish practical postulates alone. With this view he introduces at the close of his arguments the myth of the lower world, and the state of departed souls, in order, by complying with the religious notions, and traditions of his countrymen, to gain a positive support for belief in the soul’s immortality. Elsewhere Plato also speaks of the lower world, and of the future rewards and punishments of the good and the evil, in accordance with the popular notions, as though he saw the elements of a divine revelation therein; he tells of purifying punishment in Hades, analogous to a purgatory; he avails himself of the common notion to affirm that shades still subject to the corporeal principle will hover after death over their graves, seeking to recover their lifeless bodies, and at times he dilates upon the migration of the soul to various human and brute forms. On the whole, we find in Plato’s proofs of immortality, as in his psychology generally, that dualism, which here expresses itself as hatred to the corporeal, and is connected with the tendency to seek the ultimate ground of evil in the nature of the “different” and the sensible world. VI. THE PLATONIC ETHICS.—The ground idea of the good, which in physics served only as an inventive conception, finds now, in the ethics, its true exhibition. Plato has developed it prominently according to three sides, as good, as individual virtue, and as ethical world in the state. The conception of duty remains in the background with him as with the older philosophers.