Ideas won't keep; something must be done about them.

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.

Education with inert ideas is not only useless; it is above all things harmful.

Fundamental progress has to do with the reinterpretation of basic ideas.

Almost all new ideas have a certain aspect of foolishness when they are first produced

Almost all new ideas have a certain aspect of foolishness when they are first produced.