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

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

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

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

The instinctive need to be the member of a closely knit group fighting for common ideals may grow so strong that it becomes inessential what these ideals are.

Man has been driven out of the paradise in which he could trust his instincts.

The truth about an animal is far more exciting and altogether more beautiful than all the myths woven about it.