Each honest calling, each walk of life, has its own elite, its own aristocracy based on excellence.

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.

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

Public education is a great instrument of social change. Through it, if we so desire, we can make our country more nearly a democracy without classes. To do so will require the efforts of us all-teachers, administrators, taxpayers and statesmen. Education is a social process, perhaps the most important process in determining the future of our country; it should command a far larger portion of our national income than it does today.

Behold the turtle. He makes progress only when he sticks his neck out.

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.

In every section of the entire area where the word science may properly be applied, the limiting factor is a human one. We shall have rapid or slow advance in this direction or in that depending on the number of really first-class men who are engaged in the work in question. ... So in the last analysis, the future of science in this country will be determined by our basic educational policy.