Example isn't another way to teach, it is the only way to teach.

[Kepler] had to realize clearly that logical-mathematical theoretizing, no matter how lucid, could not guarantee truth by itself; that the most beautiful logical theory means nothing in natural science without comparison with the exactest experience. Without this philosophic attitude, his work would not have been possible.

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.

I see in Nature a magnificent structure... that must fill a thinking person with a feeling of humility.

With fame I become more and more stupid, which of course is a very common phenomenon.

The pursuit of truth and beauty is a sphere of activity in which we are permitted to remain children all our lives.

Mysticism is in fact the only criticism people cannot level against my theory.