When I have clarified and exhausted a subject, then I turn away from it, in order to go into darkness again.

When a philosopher says something that is true then it is trivial. When he says something that is not trivial then it is false.

The enchanting charms of this sublime science reveal only to those who have the courage to go deeply into it.

I have had my results for a long time: but I do not yet know how I am to arrive at them.

I am coming more and more to the conviction that the necessity of our geometry cannot be demonstrated, at least neither by, nor for, the human intellect.

Life stands before me like an eternal spring with new and brilliant clothes.