Historians will have to face the fact that natural selection determined the evolution of cultures in the same manner as it did that of species.
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.
It is a good morning exercise for a research scientist to discard a pet hypothesis every day before breakfast. It keeps him young.
Truth in science can best be defined as the working hypothesis best suited to open the way to the next better one.