Fundamental progress has to do with the reinterpretation of basic ideas.
Fools act on imagination without knowledge, pedants act on knowledge without imagination.
Familiar things happen, and mankind does not bother about them. It requires a very unusual mind to undertake the analysis of the obvious.
Life is an offensive, directed against the repetitious mechanism of the Universe.
Everything of importance has been said before by somebody who did not discover it.
Ideas won't keep; something must be done about them.
No period of history has ever been great or ever can be that does not act on some sort of high, idealistic motives, and idealism in our time has been shoved aside, and we are paying the penalty for it.
No one who achieves success does so without acknowledging the help of others. The wise and confident acknowledge this help with gratitude.
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.