Man is an intelligence in servitude to his organs.

Every man's memory is his private literature.

The course of every intellectual, if he pursues his journey long and unflinchingly enough, ends in the obvious, from which the non-intellectuals have never stirred.

A physical shortcoming could produce a kind of mental excess. The process, it seemed, was reversible. Mental excess could produce, for its own purposes, the voluntary blindness and deafness of deliberate solitude, the artificial impotence of asceticism.

You never see animals going through the absurd and often horrible fooleries of magic and religion. . . . Only man behaves with such gratuitous folly. It is the price he has to pay for being intelligent but not, as yet, quite intelligent enough.

Man is so intelligent that he feels impelled to invent theories to account for what happens in the world. Unfortunately, he is not quite intelligent enough, in most cases, to find correct explanations. So that when he acts on his theories, he behaves very often like a lunatic.