I always wondered at Socrates' idea that if you know that a certain way to live or that certain actions are evil, you couldn't do them. I know people do things, and later regret them. And that means that have some knowledge after the fact that if they had had before would have made it impossible to do what they regret. And that we can rationalize almost anything to keep ourselves from knowing exactly what we are doing. But doesn't, say, Macbeth know that what he is doing is evil, and does it anyway? Are there any good arguments for Socrates?