Man appears to be the missing link between anthropoid apes and human beings.

I believe that present day civilized man suffers from insufficient discharge of his aggressive drive

It is a good morning exercise for a research scientist to discard a pet hypothesis every day before breakfast. It keeps him young.

More than any other product of human scientific culture scientific knowledge is the collective property of all mankind.

Every man gets a narrower and narrower field of knowledge in which he must be an expert in order to compete with other people. The specialist knows more and more about less and less and finally knows everything about nothing.

We do not take humor seriously enough.

Truth in science can be defined as the working hypothesis best suited to open the way to the next better one.