Almost in the same way as earlier physicists are said to have found suddenly that they had too little mathematical understanding to be able to master physics; we may say that young people today are suddenly in the position that ordinary common sense no longer suffices to meet the strange demands life makes. Everything has become so intricate that for its mastery an exceptional degree of understanding is required. For it is not enough any longer to be able to play the game well; but the question is again and again: what sort of game is to be played now anyway?

What is troubling us is the tendency to believe that the mind is like a little man within.

Ethics and aesthetics are one.

If in life we are surrounded by death, so too in the health of our intellect by madness.

Logic is not a body of doctrine, but a mirror-image of the world. Logic is transcendental.

Resting on your laurels is as dangerous as resting when you are walking in the snow. You doze off and die in your sleep.

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