Jowett: immortality of the soul

There is nothing new, he said, in what I am about to tell you ; but only what I have been always and everywhere repeating in the previous discussion and on other occasions : I want to show you the nature of that cause which has occupied my thoughts, and I shall have to go back to those familiar words which are in the mouth of everyone, and first of all assume that there is an absolute beauty and goodness and greatness, and the like ; grant me this, and I hope to be able to show you the nature of the cause, and to prove the immortality of the soul. PHAEDO  

But if someone who would rather not admit the immortality of the soul boldly denies this, and says that the dying do really become more evil and unrighteous, then, if the speaker is right, I suppose that injustice, like disease, must be assumed to be fatal to the unjust, and that those who take this disorder die by the natural inherent power of destruction which evil has, and which kills them sooner or later, but in quite another way from that in which, at present, the wicked receive death at the hands of others as the penalty of their deeds ? THE REPUBLIC   BOOK X