And yet the rewards of virtue are greater far than I have described. ‘And can we conceive things greater still?’ Not, perhaps, in this brief span of life: but should an immortal being care about anything short of eternity? ‘I do not understand what you mean?’ Do you not know that the soul is immortal? ‘Surely you are not prepared to prove that?’ Indeed I am. ‘Then let me hear this argument, of which you make so light.’
You would admit that everything has an element of good and of evil. In all things there is an inherent corruption; and if this cannot destroy them, nothing else will. The soul too has her own corrupting principles, which are injustice, intemperance, cowardice, and the like. But none of these destroy the soul in the same sense that disease destroys the body. The soul may be full of all iniquities, but is not, by reason of them, brought any nearer to death. Nothing which was not destroyed from within ever perished by external affection of evil. The body, which is one thing, cannot be destroyed by food, which is another, unless the badness of the food is communicated to the body. Neither can the soul, which is one thing, be corrupted by the body, which is another, unless she herself is infected. And as no bodily evil can infect the soul, neither can any bodily evil, whether disease or violence, or any other destroy the soul, unless it can be shown to render her unholy and unjust. But no one will ever prove that the souls of men become more unjust when they die. If a person has the audacity to say the contrary, the answer is—Then why do criminals require the hand of the executioner, and not die of themselves? ‘Truly,’ he said, ‘injustice would not be very terrible if it brought a cessation of evil; but I rather believe that the injustice which murders others may tend to quicken and stimulate the life of the unjust.’ You are quite right. If sin which is her own natural and inherent evil cannot destroy the soul, hardly will anything else destroy her. But the soul which cannot be destroyed either by internal or external evil must be immortal and everlasting. And if this be true, souls will always exist in the same number. They cannot diminish, because they cannot be destroyed; nor yet increase, for the increase of the immortal must come from something mortal, and so all would end in immortality. Neither is the soul variable and diverse; for that which is immortal must be of the fairest and simplest composition. If we would conceive her truly, and so behold justice and injustice in their own nature, she must be viewed by the light of reason pure as at birth, or as she is reflected in philosophy when holding converse with the divine and immortal and eternal. In her present condition we see her only like the sea-god Glaucus, bruised and maimed in the sea which is the world, and covered with shells and stones which are incrusted upon her from the entertainments of earth.