I believe that both art and the human striving for cognitive comprehension are manifest forms of the grand game in which nothing more is stipulated than the game's rules; both art and actively solicited perceptions are but special cases of the recurring creative act to which we owe our existence.

All living beings have received their weapons through the same process of evolution that moulded their impulses and inhibitions; for the structural plan of the body and the system of behaviour of a species are parts of the same whole.... Wordsworth is right: there is only one being in possession of weapons which do not grow on his body and of whose working plan, therefore, the instincts of his species know nothing and in the usage of which he has no correspondingly adequate inhibition.

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.

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.

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

The bond with a dog is as lasting as the ties of this earth can ever be.

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.