An open mind is all very well in its way, but it ought not to be so open that there is no keeping anything in or out of it.

The only use of knowledge of the past is to equip us for the present.

No one who achieves success does so without acknowledging the help of others. The wise and confident acknowledge this help with gratitude.

The tragedy of the world is that those who are imaginative have but slight experience, and those who are experienced have feeble imaginations.

The difference between ancients and moderns is that the ancients asked what have we experienced, and moderns asked what can we experience.

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.

The antithesis between a technical and a liberal education is fallacious. There can be no adequate technical education which is not liberal, and no liberal education which is not technical.