As long as there are sovereign nations possessing great power, war is inevitable.

Mathematics deals exclusively with the relations of concepts to each other without consideration of their relation to experience.

One must not attempt to justify them, but rather to sense their nature simply and clearly.

Man has an intense desire for assured knowledge.

O, Youth: Do you know that yours is not the first generation to yearn for a life full of beauty and freedom?

I have never obtained any ethical values from my scientific work.

People should be more like animals . . . they should be more intuitive; they should not be too conscious of what they do while they do it.