No science can be more secure than the unconscious metaphysics which tacitly it presupposes.

Each generation criticizes the unconscious assumptions made by its parent. It may assent to them, but it brings them out in the open.

In all education the main cause of failure is staleness.

Religion will not regain its old power until it can face change in the same spirit as does science.

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.

[In many circumstances,] the most important thing about a proposition is not that it be true, but that it be interesting.

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