Only a life lived for others is a life worthwhile.

In the teaching of geography and history a sympathetic understanding (should) be fostered for the characteristics of the different peoples of the world, especially for those who we are in the habit of describing as "primitive.

All the fifty years of conscious brooding have brought me no closer to answer the question, "What are light quanta?" Of course today every rascal thinks he knows the answer, but he is deluding himself.

Stupidity is a personal achievement which transcends national boundaries.

I think that only daring speculation can lead us further and not accumulation of facts.

I know that it is a hopeless undertaking to debate about fundamental value judgements. For instance, if someone approves, as a goal, the extirpation of the human race from the earth, one cannot refute such a viewpoint on rational grounds. But if there is agreement on certain goals and values, one can argue rationally about the means by which these objectives may be obtained.

It may be possible to fight intolerance, stupidity, and fanaticism seperately, but when they come together there is no hope.