To start with invention is the mark of the fertile mind ... and leads later to the interpretation of experience; to start with the reproduction of experience is the infallible index of a barren invention.

Birth is beastly - and death - and digestion, if it comes to that. Sometimes when I think of what's happening inside me to a beautiful suprème de sole, with the caviare in boats, and the croûtons and the jolly little twists of potato and all the gadgets - I could cry. But there it is, don't you know.

There's truth as far as you knows it; and there's truth as far as you're asked for it. But they don't represent the whole truth - not necessarily.

But if it ever occurs to people to value the honor of the mind equally with the honor of the body, we shall get a social revolution of a quite unparalleled sort — and very different from the kind that is being made at the moment.

The only ethical principle which has made science possible is that the truth shall be told all the time. If we do not penalize false statements made in error, we open up the way for false statements by intention. And a false statement of fact, made deliberately, is the most serious crime a scientist can commit.

If people will bring dynamite into a powder factory, they must expect explosions.

We cannot really look at the movement of the Spirit, just because It is the Power by which we do the looking.