Plato (428-348 B.C.)
by Raphael Sanzio

Plato on the topic of evil:

Theodorus: If you could convince everyone, Socrates, as you convince me,
there would be more peace and fewer evils in the world.
Socrates: Evils, Theodorus, can never be done away with, for the good must always have its contrary; nor have they any place in the divine world, but they must needs haunt this region of our mortal nature. That is why we should make all speed to take flight from this world to the other, and that means becoming like the divine so far as we can, and that again is to become righteous with the help of wisdom. But it is no such easy matter to convince men that the reasons for avoiding wickedness and seeking after goodness are not those which the world gives. The right motive is not that one should seem innocent and good— that is no better, to my thinking, than an old wives' tale— but let us state the truth in this way. In the divine there is no shadow of unrighteousness, only the perfection of righteousness, and nothing is more like the divine than any one of us who becomes as righteous as possible. It is here that a man shows his true spirit and power or lack of spirit and nothingness. For to know this is wisdom and excellence of the genuine sort; not to know it is to be manifestly blind and base.
— Theaetetus 176a-c (translated by F.M. Cornford, pp. 880-881)

Socrates: As it is, you will leave this place, when you do, as the victim of a wrong done not by us, the laws, but by you fellow men. But if you leave in that dishonorable way, returning wrong for wrong and evil for evil, breaking your agreements and covenants with us, and injuring those whom you least ought to injure— yourself, your friends, your country, and us— then you will have to face our anger in your lifetime, and in that place beyond when the laws of the other world know that you have tried, so far as you could, to destroy even us their brothers, they will not receive you with a kindly welcome. Do not take Crito's advice, but follow ours.
— Crito 54c (translated by Hugh Tredennick, p. 39)

Socrates: Sickness you will allow, is an evil, the art of medicine, both useful and good. Yes. But a body, if I mistake not, in so far as it is a body, is neither good nor evil. Exactly. A body though is compelled, on account of sickness, to embrace and love the medical art. I think so. That, then, which is neither evil nor good becomes friendly with good, on account of the presence of evil. Apparently. But evidently it becomes so before it is itself made evil by the evil which it contains. For, once become evil, it can no longer, you will allow, be desirous of or friendly with good, for evil, we said, cannot possibly be friendly with good.
    When it is not evil as yet, though evil be present with it, this very presence of evil makes it desirous of good, but the presence which makes it evil deprives it, at the same time, of its desire and friendship for good. For it is no longer a thing neither evil nor good, but already evil, and evil, we said, cannot be friendly with good.
    True, it cannot be. On the same ground then we may further assert that those who are already wise are no longer friends to wisdom, be they gods, or be they men, nor, again, are those friends to wisdom who are so possessed of foolishness, but who are not, as yet, in consquence of it, foolish or ignorant, but still understand that they do not know the things they do not know. And thus, you see, it is those who are neither good nor evil, as yet, that are friends to wisdom [philosophers], but those who are evil are not friends, nor again are the good. For that contrary is not friendly with contrary, nor like with like, was made apparent in the former part of our discourse.
— Lysis 217b-c, 218a-b (translated by J. Wright, pp. 161-162)

Socrates: You speak of good and evil, do you not? I do... That which destroys and corrupts in every case is the evil; that which preserves and benefits is the good... Do you say that there is for everythng its special good and evil, as for example for the eyes ophthalmia, for the entire body disease, for grain mildew, rotting for wood, rust for bronze and iron, and, as I say, for practically everything its congenital evil and disease? I do, he said. Then when one of these evils comes to anything does it not make the thing to which it attaches itself bad, and finally disintegrate and destroy it? Of course. Then the congenital evil of each thing and its own vice destroys it, or if that is not going to destroy it, nothing else remains that could, for obviously the good will never destroy anything, nor yet again will that which is neutral and neither good nor evil... Well, then, said I, has not the soul something that makes it evil? Indeed it has, he said, all the things that we were just now enumerating, injustice and licentiousness and cowardice and ignorance. Does any one of these things dissovle and destroy it? And reflect, lest we be misled by supposing that when an unjust and foolish man is taken in his injustice he is then destroyed by the injustice, which is the vice of the soul. But conceive it thus. Just as the vice of the body which is disease wastes and destroys it so that it no longer is a body at all, in like manner in all the examples of which we spoke it is the specific evil which, by attaching itself to the thing and dwelling in it with power to corrupt, reduces it to nonentity. Is not that so? Yes. Come, then, and consider the soul in the same way. Do injustice and other wickedness dwelling in it, by their indwelling and attachment to it, corrupt and wither it till they bring it to death and separate it from the body?
— Republic X.608d-609e (translated by Paul Shorey, pp. 833-834)

Athenian: For the good man 'tis most glorious and good and profitable to happiness of life, aye, and most excellently fit, to do sacrifice and be ever in communion with heaven through prayer and offerings and all manner of worship, but for the evil, entirely the contrary. For the evil man is impure of soul, where the other is pure, and from the polluted neither good men nor God may ever rightly accept a gift; thus all this toil taken with heaven is but labor thrown away for the impious, though ever seasonable in the pious.
— Laws IV.716d-717a (translated by A.E. Taylor, pp. 1307-1308)

Athenian: But as concerns the transgressions of those who commit wrong, but reparable wrong, we must first of all rest assured that no wrongdoer is so of deliberation. For no man will ever deliberately admit supreme evil, and least of all in his most precious possessions. But every man's most precious possession, as we said, is his soul; no man, then, we may be sure, will of set purpose receive the supreme evil into this most precious thing and live with it there all his life through. And yet, though a wrongdoer or a man in evil case is always a pitiable creature, it is with him whose disease is curable that there is scope for pity. With him one may curb and tame one's passion, and not scold like a vixen, but against the unqualified and incorrigible offender, the utterly corrupt, we must give the rein to wrath. This is why we say it is meet for a good man to be high-spirited and gentle, as occasion requires.
— Laws V.731c-d (translated by A.E. Taylor, pp. 1317-1318)

Epistle VII: For when a man makes the highest ideals his aim for himself and for his city and accepts the consequences, in his fate there is nothing amiss or ignoble. None of us is born immortal, nor would being so bring happiness, as most people think. Nothing good or evil worth considering befalls that which has no soul. Only to a soul either in the body or separated from it can good or evil occur. We must at all times give our unfeigned assent to the ancient and holy doctrines which warn us that our souls are immortal, that they are judged, and that they suffer the severest punishments after our separation from the body. Hence we must also hold it a lesser evil to be victims of great wrongs and crimes than to be doers of them. The man who crams his moneybags while his soul starves does not listen to these doctrines, or, if he does, he laughs them to scorn, as he supposes, and on every side ruthlessly snatches like a beast whatever he hopes will provide him with food and drink or the satisfaction of that brutal and gross pleasure that has no right to be called by a name derived from the goddess Aphrodite. He is blind and does not see that consequences attend the abominable wickedness of his acts of violence, for each wrongdoing adds the weight to a burden which the sinner must drag with him, not only while he lives his life on earth, but after he has returned to the underworld whence he came— a journey unhonored and miserable altogether and always.
— Plato's Seventh Letter 335a-c (translated by L.A. Post, p. 1583)