Experience is knowledge. All the rest is information.

There are moments when one feels free from one's own identification with human limitations and inadequacies. At such moments one imagines that one stands on some spot of a small planet, gazing in amazement at the cold yet profoundly moving beauty of the eternal, the unfathomable; life and death flow into one, and there is neither evolution nor destiny; only Being.

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

All that is valuable in human society depends upon the opportunity for development accorded the individual.

I would absolutely refuse any direct or indirect war service and would try to persuade my friends to do the same, regardless of the reasons for the cause of a war.

My deep religiosity [...] found an abrupt ending at the age of twelve, through the reading of popular scientific books.

The most important human endeavor is the striving for morality in our actions.