I am willing to allow that smoking is a moral weakness, but on the other hand, we must beware of the man without weaknesses. He is not to be trusted. He is apt to be always sober and he cannot make a single mistake. His habits are likely to be regular, his existence more mechanical and his head always maintains its supremacy over his heart. Much as I like reasonable persons, I hate completely rational beings.

The Importance of Living (ed. 1940)