Conventional words or other signs have to be sought for laboriously only in a second stage, where the associative play already referred to is sufficiently established and can be reproduced at will.

We should be on our guard not to overestimate science and scientific methods when it is a question of human problems, and we should not assume that experts are the only ones who have the right to express themselves on questions affecting the organization of society.

Formerly, people thought that if matter disappeared from the universe, space and time would remain. Relativity declares that space and time would disappear with matter.

The Bible is a collection of honorable, but primitive legends which are still nevertheless pretty childish.

I cannot accept any concept of God based on the fear of life or the fear of death, or blind faith. I cannot prove to you that there is no personal God, but if I were to speak of him I would be a liar.

The most important tool of the theoretical physicist is his wastebasket.

I never think of the future. It comes soon enough. When visiting the U.S. from Germany for a winter academic stay.