Plato, Republic

[610a] But the body being one thing and the foods something else, we shall never expect the body to be destroyed by their badness, that is by an alien evil that has not produced in it the evil that belongs to it by nature.” “You are entirely right,” he replied.

“On the same principle,” said I, “if the badness of the body does not produce in the soul the soul's badness we shall never expect the soul to be destroyed by an alien evil apart from its own defect—one thing, that is, by the evil of another.” “That is reasonable,” he said. “Either, then, we must refute this [610b] and show that we are mistaken, or,¹ so long as it remains unrefuted, we must never say that by fever or any other disease, or yet by the knife at the throat or the chopping to bits of the entire body, there is any more likelihood of the soul perishing because of these things, until it is proved that owing to these affections of the body the soul itself becomes more unjust and unholy. But when an evil of something else occurs in a different thing and the evil that belongs to the thing is not engendered in it, [610c] we must not suffer it to be said that the soul or anything else is in this way destroyed.” “But you may be sure,” he said, “that nobody will ever prove this, that the souls of the dying are made more unjust by death.” “But if anyone,” said I, “dares to come to grips with the argument² and say, in order to avoid being forced to admit the soul's immortality, that a dying man does become more wicked and unjust,³ we will postulate that, if what he says is true, injustice must be fatal [610d] to its possessor as if it were a disease, and that those who catch it die because it kills them by its own inherent nature, those who have most of it quickest, and those who have less more slowly, and not, as now in fact happens, that the unjust die owing to this but by the action of others who inflict the penalty.” “Nay, by Zeus,” he said, “injustice will not appear a very terrible thing after all if it is going to be⁴ fatal to its possessor, for that would be a release from all troubles.⁵ But I rather think it will prove to be quite the contrary, [610e] something that kills others when it can, but renders its possessor very lively indeed,⁶ and not only lively but wakeful,⁷ so far, I ween, does it dwell⁸ from deadliness.” “You say well,” I replied; “for when the natural vice and the evil proper to it cannot kill and destroy the soul, still less⁹ will the evil appointed for the destruction of another thing destroy the soul or anything else, except that for which it is appointed.”¹⁰ “Still less indeed,” he said, “in all probability.” “Then since it is not destroyed by any evil whatever,