Courage, not cleverness; not even inspiration, is the grain of mustard that grows up to be a great tree.

I act with complete certainty. But this certainty is my own.

The truth of the thoughts that are here set forth seems to me unassailable and definitive. I therefore believe myself to have found, on all essential points, the final solution of the problems. And if I am not mistaken in this belief, then the second thing in which the value of this work consists is that it shows how little is achieved when these problems are solved.

I'm doing philosophy like an old woman, first I'm looking for my pencil, then I'm looking for my glasses, then I'm looking for my pencil again.

Is it even always an advantage to replace an indistinct picture by a sharp one? Isn't the indistinct one often what we need?

An honest religious thinker is like a tightrope walker. He almost looks as though he were walking on nothing but air. His support is the slenderest imaginable. And yet it really is possible to walk on it.

All I know is what I have words for.