Science repudiates philosophy. In other words, it has never cared to justify its truth or explain its meaning.

It is a safe rule to apply that, when a mathematical or philosophical author writes with a misty profundity, he is talking nonsense.

It is the business of the future to be dangerous; and it is among the merits of science that it equips the future for its duties.

It must be admitted that there is a degree of instability which is inconsistent with civilization. But, on the whole, the great ages have been unstable ages.

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

There are two principles inherent in the very nature of things, recurring in some particular embodiments whatever field we explore - the spirit of change, and the spirit of conservation. There can be nothing real without both. Mere change without conservation is a passage from nothing to nothing. . . . Mere conservation without change cannot conserve. For after all, there is a flux of circumstance, and the freshness of being evaporates under mere repetition.

It is the business of the future to be dangerous.