Chapter XIII.--Theory of the Soul's Immortality.
The soul is not in itself immortal, O Greeks, but mortal.  Yet it is possible for it not to die. If, indeed, it knows not the truth, it dies, and is dissolved with the body, but rises again at last at the end of the world with the body, receiving death by punishment in immortality. But, again, if it acquires the knowledge of God, it dies not, although for a time it be dissolved. In itself it is darkness, and there is nothing luminous in it. And this is the meaning of the saying, "The darkness comprehendeth not the light."  For the soul does not preserve the spirit, but is preserved by it, and the light comprehends the darkness. The Logos, in truth, is the light of God, but the ignorant soul is darkness. On this account, if it continues solitary, it tends downward towards matter, and dies with the flesh; but, if it enters into union with the Divine Spirit, it is no longer helpless, but ascends to the regions whither the Spirit guides it: for the dwelling-place of the spirit is above, but the origin of the soul is from beneath. Now, in the beginning the spirit was a constant companion of the soul, but the spirit forsook it because it was not willing to follow. Yet, retaining as it were a spark of its power, though unable by reason of the separation to discern the perfect, while seeking for God it fashioned to itself in its wandering many gods, following the sophistries of the demons. But the Spirit of God is not with all, but, taking up its abode with those who live justly, and intimately combining with the soul, by prophecies it announced hidden things to other souls. And the souls that are obedient to wisdom have attracted to themselves the cognate spirit;  but the disobedient, rejecting the minister of the suffering God,  have shown themselves to be fighters against God, rather than His worshippers.