When you are philosophizing you have to descend into primeval chaos and feel at home there.

Philosophy hasn't made any progress? - If somebody scratches the spot where he has an itch, do we have to see some progress? Isn't genuine scratching otherwise, or genuine itching itching? And can't this reaction to an irritation continue in the same way for a long time before a cure for the itching is discovered?

When we think about the future of the world, we always have in mind its being where it would be if it continued to move as we see it moving now. We do not realize that it moves not in a straight line and that its direction changes constantly.

The sense of the world must lie outside the world... What we cannot speak about we must remain silent about... What can be described can happen too, and what is excluded by the laws of causality cannot be described.

A philosopher who is not taking part in discussions is like a boxer who never goes into the ring.

Philosophy can be said to consist of three activities: to see the commonsense answer, to get yourself so deeply into the problem that the common sense answer is unbearable, and to get from that situation back to the commonsense answer.

No one likes having offended another person; hence everyone feels so much better if the other person doesn't show he's been offended. Nobody likes being confronted by a wounded spaniel. Remember that. It is much easier patiently - and tolerantly - to avoid the person you have injured than to approach him as a friend. You need courage for that.