It is truly strange how long it takes to get to know oneself. I am now sixty two years old, yet just one moment ago I realised that I absolutely love lightly toasted bread. Simultaneously, I also realised that I loathe bread when it is heavily toasted. For almost sixty years, and quite unconsciously, I have been experiencing inner joy or total despair at my relationship with grilled bread.

All mathematics is tautology.

You can't think decently if you're not willing to hurt yourself

We regard the photograph, the picture on our wall, as the object itself (the man, landscape, and so on) depicted there. This need not have been so. We could easily imagine people who did not have this relation to such pictures. Who, for example, would be repelled by photographs, because a face without color and even perhaps a face in reduced proportions struck them as inhuman.

One can mistrust one's own senses, but not one's own belief.

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.

You learned the concept 'pain' when you learned language.