A man's ethical behaviour should be based effectually on sympathy, education, and social ties and needs; no religious basis is necessary. Man would indeed be in a poor way if he had to be restrained by fear of punishment and hope of reward after death.

There are yet people who say there is no God. But what really makes me angry is that they quote me for the support of such views

You teach me baseball and I'll teach you relativity...No we must not. You will learn about relativity faster than I learn baseball.

It is a magnificent feeling to recognize the unity of complex phenomena which appear to be things quite apart from the direct visible truth.

I do know that kind fate allowed me to find a couple of nice ideas after many years of feverish labor.

The Jewish scriptures admirably illustrate the development from the religion of fear to moral religion, a development continued in the New Testament. The religions of all civilized peoples, especially the peoples of the Orient, are primarily moral religions.

Lasting harmony with a woman (was) an undertaking in which I twice failed rather disgracefully.