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.

It is an hypothesis that the sun will rise tomorrow: and this means that we do not know whether it will rise.

I might say: if the place I want to get to could only be reached by way of a ladder, I would give up trying to get there. For the place I really have to get to is a place I must already be at now. Anything that I might reach by climbing a ladder does not interest me.

Don't for heaven's sake, be afraid of talking nonsense! But you must pay attention to your nonsense.

I am not interested in constructing a building, so much as in having a perspicuous view of the foundations of possible buildings.

A picture whose pictorial form is logical form is called a logical picture.

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.