It is the duty of the human understanding to understand that there are things which it cannot understand, and what those things are. Human understanding has vulgarly occupied itself with nothing but understanding, but if it would only take the trouble to understand itself at the same time it would simply have to posit the paradox.

But doubt is wily and cunning and never, as it is sometimes said to be, loud or defiant. It is unassuming and sly, not bold or assertive - and the more unassuming, the more dangerous.

People settle for a level of despair they can tolerate and call it happiness.

One is not unpopular because he uses peculiar expressions; that just so happens; such terms become a fad, and by and by everybody, down to the last simpleton, uses them. But a person who follows through an idea in his mind is, and always will be, essentially unpopular. That is why Socrates was unpopular, though he did not use any special terms, for to grasp and hold his 'ignorance' requires greater vital effort than understanding the whole of Hegel's philosophy.

O Luther, you had 95 theses . . . The matter is far more terrible-there is only one thesis. The Christianity of the New Testament does not exist at all. Here there is nothing to reform.

Certainty... lurks at the door of faith and threatens to devour it.

Faith is holding onto uncertainties with passionate conviction.