Each honest calling, each walk of life, has its own elite, its own aristocracy based on excellence of performance. . . . There will always be the false snobbery which tries to place one vocation above another. You will become a member of the aristocracy in the American sense only if your accomplishments and integrity earn this appellation.

The stumbling way in which even the ablest of the scientists in every generation have had to fight through thickets of erroneous observations, misleading generalizations, inadequate formulation, and unconscious prejudice is rarely appreciated by those who obtain their scientific knowledge from textbooks.

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.

He who enters a university walks on hallowed ground.

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

Science is a dynamic undertaking directed to lowering the degree of the empiricism involved in solving problems; or, if you prefer, science is a process of fabricating a web of interconnected concepts and conceptual schemes arising from experiments and observations and fruitful of further experiments and observations.

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