From The Republic
And no good thing is hurtful?
And that which is not hurtful hurts not?
And that which hurts not does no evil?
And can that which does no evil be a cause of evil?
And the good is advantageous?
And therefore the cause of well-being?
It follows therefore that the good is not the cause of all things, but of the good only?
Then God, if he be good, is not the author of all things, as the many assert, but he is the cause of a few things only, and not of most things that occur to men. For few are the goods of human life, and many are the evils, and the good is to be attributed to God alone; of the evils the causes are to be sought elsewhere, and not in him.
That appears to me to be most true, he said.