...the only simplicity to be trusted is the simplicity to be found on the far side of complexity.

The real history does not get written, because it is not in people's brains but in their nerves and vitals.

The art of progress is to preserve order amid change and to preserve change amid order.

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.

I regret that it has been necessary for me in this lecture to administer a large dose of four-dimensional geometry. I do not apologize, because I am really not responsible for the fact that nature in its most fundamental aspect is four-dimensional. Things are what they are.

Everything of importance has been said before by somebody who did not discover it.

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