Only a man who lives not in time but in the present is happy.

A tautology's truth is certain, a proposition's possible, a contradiction's impossible.

The world is everything that is the case.

If I have exhausted the justifications, I have reached bedrock and my spade is turned. Then I am inclined to say: 'This is simply what I do.

The problems are solved, not by giving new information, but by arranging what we have always known.

I am sitting with a philosopher in the garden; he says again and again 'I know that that’s a tree', pointing to a tree that is near us. Someone else arrives and hears this, and I tell him: 'This fellow isn’t insane. We are only doing philosophy.

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.