I Once wrote: "In mathematics process and result are equivalent."

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.

You must always be puzzled by mental illness. The thing I would dread most, if I became mentally ill, would be your adopting a common sense attitude; that you could take it for granted that I was deluded.

The child learns to believe a host of things. I.e. it learns to act according to these beliefs. Bit by bit there forms a system of what is believed, and in that system some things stand unshakeably fast and some are more or less liable to shift. What stands fast does so, not because it is intrinsically obvious or convincing; it is rather held fast by what lies around it.

One can defend common sense against the attacks of philosophers only by solving their puzzles, i.e., by curing them of the temptation to attack common sense.

Nothing is more important for teaching us to understand the concepts we have than to construct fictitious ones.

Don't get involved in partial problems, but always take flight to where there is a free view over the whole single great problem, even if this view is still not a clear one.