Whoever has overthrown an existing law of custom has always first been accounted a bad man: but when, as did happen, the law could not afterwards be reinstated and this fact was accepted, the predicate gradually changed; - history treats almost exclusively of these bad men who subsequently became good men!
When one has finished building one's house, one suddenly realizes that in the process one has learned something that one really needed to know in the worst way - before one began.
It was Christianity, with its heartfelt resentment against life, that first made something unclean of sexuality: it threw filth on the origin, on the essential fact of our life.