Every vital organization owes its birth and life to an exciting and daring idea.

Science advances, not by the accumulation of new facts, but by the continuous development of new concepts.

Even the development of the steam engine owed but little to the advancement of science.

Every vital organization owes its birth and life to an exciting and daring idea.

A conceptual scheme is never discarded merely because of a few stubborn facts with which it cannot be reconciled; a conceptual scheme is either modified or replaced by a better one, never abandoned with nothing left to take its place.

I venture to define science as a series of interconnected concepts and conceptual schemes arising from experiment and observation and fruitful of further experiments and observations. The test of a scientific theory is, I suggest, its fruitfulness.

Some of mankind's most terrible misdeeds have been committed under the spell of certain magic words or phrases.