Aristotle discovered all the half-truths which were necessary to the creation of science.

Without adventure all civilization is full of decay. Adventure rarely reaches its predetermined end. Columbus never reached China.

Mathematics, in its widest significance, is the development of all types of formal, necessary, deductive reasoning.

Education which is not modern share the fate of all organic things which are kept too long.

The only use of a knowledge of the past is to equip us for the present. The present contains all that there is. It is holy ground; for it is the past, and it is the future.

Our rate of progress is such that an individual human being, of ordinary length of life, will be called on to face novel situations which find no parallel in his past. The fixed person, for the fixed duties, who, in older societies was such a godsend, in the future will be a public danger.

The preternatural solemnity of a good many of the professionally religious is to me a point against them.