Put off your imagination, as you put off your overcoat, when you enter the laboratory. Put it on again, as you put on your overcoat, when you leave.

It is what we know already that often prevents us from learning.

The experimenter who does not know what he is looking for will not understand what he finds.

When we meet a fact which contradicts a prevailing theory, we must accept the fact and abandon the theory, even when the theory is supported by great names and generally accepted.

Man can learn nothing unless he proceeds from the known to the unknown.

The terrain is everything; the germ is nothing.

Art is 'I'; science is 'we'.

A fact in itself is nothing. It is valuable only for the idea attached to it, or for the proof which it furnishes.

Those who do not know the torment of the unknown cannot have the joy of discovery.

Science increases our power in proportion as it lowers our pride.

All the vital mechanisms, varied as they are, have only one object, that of preserving constant the conditions of life in the internal environment.

What should a good children’s book be like? If you ask me, I can tell you after thinking long and hard: It must be good.

The one who loves you has the right to tick you off, to correct you when you go wrong and admonish you when you repeat.

...You know, one good apple can spoil the rest, ” Colonel Korn concluded with conscious irony.

There's no such thing as a limited victory. Every victory leaves another resentment, another defeated and humiliated people. Another place to guard and defend and fear.

Love always gives freedom.

Boldness and decision command, often even in evil, the respect and concurrence of mankind.

Upon hearing via Littlewood an exposition on the theory of relativity: To think I have spent my life on absolute muck.

I think of music as a menu. I can't eat the same thing every day.

We are all the foolishness and all the crimes we did. We're also all the kindnesses we did. I hate to think of life as if we understood time. We don't understand time.

Management is all about managing in the short term, while developing the plans for the long term.