Morality

When a man is getting better he understands more and more clearly the evil that is still left in him.
When a man is getting worse he understands his own badness less and less.
A moderately bad man knows he is not very good: a thoroughly bad man thinks he is all right.

You can understand sleep when you are awake, not while you are sleeping.
You can understand the nature of drunkenness when you are sober, not when you are drunk.

Good people know about both good and evil. Bad people do not know about either.

-C.S Lewis