The great achievements of the past were the adventures of the past. Only the adventurous can understand the greatness of the past.

Ninety percent of our lives is governed by emotion.

Some of the finest moral intuitions come to quite humble people. The visiting of lofty ideas doesn't depend on formal schooling.

I consider Christian theology to be one of the great disasters of the human race.

There is no greater hindrance to the progress of thought than an attitude of irritated party-spirit.

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 vitality of thought is in adventure. Ideas won't keep. Something must be done about them. When the idea is new, its custodians have fervor, live for it, and if need be, die for it.