Freedom of teaching and of opinion in book or press is the foundation for the sound and natural development of any people.

The conflict that exists today is no more than an old-style struggle for power, once again presented to mankind in semireligious trappings. The difference is that, this time, the development of atomic power has imbued the struggle with a ghostly character; for both parties know and admit that, should the quarrel deteriorate into actual war, mankind is doomed.

Gravity is a response to geometry.

The more I learn of physics, the more I am drawn to metaphysics.

When the nazis came to power, I looked to the universities that prided themselves upon their intellectual freedom, and they failed me. I looked to the German press, which prided itself on the freedom of the press, and it failed me. Until at last the churches stood alone, and that for which I once had little regard earned my respect.

Everyone should be respected as an individual, but no one idolized.

Without deep reflection one knows from daily life that one exists for other people.