It seems to me that, in every culture, I come across a chapter headed 'Wisdom.' And then I know exactly what is going to follow: 'Vanity of vanities, all is vanity.'

We could present spatially an atomic fact which contradicted the laws of physics, but not one which contradicted the laws of geometry.

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.

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.

In order to draw a limit to thinking, we should have to think both sides of this limit.

The world is independent of my will.

Man feels the urge to run up against the limits of language. Think for example of the astonishment that anything at all exists. This astonishment cannot be expressed in the form of a question, and there is also no answer whatsoever. Anything we might say is a priori bound to be nonsense. Nevertheless we do run up against the limits of language. Kierkegaard too saw that there is this running up against something, and he referred to it in a fairly similar way (as running up against paradox). This running up against the limits of language is ethics.