[Intellectual courage is] the quality that allows one to believe in one's judgement in the face of disappointment and widespread skepticism. Intellectual courage is even rarer than physical courage.

A wise man in China asked his gardener to plant a shrub. The gardener objected that it only flowered once in a hundred years. “In that case,” said the wise man, “plant it immediately.” [On the importance of fundamental research.]

Authority in science exists to be questioned, since heresy is the spring from which new ideas flow.

Difficulties [in defining mathematics with full generality, yet simplicity] are but consequences of our refusal to see that mathematics cannot be defined without acknowledging its most obvious feature: namely, that it is interesting. Nowhere is intellectual beauty so deeply felt and fastidiously appreciated.

Discoveries that are anticipated are seldom the most valuable. … It’s the scientist free to pilot his vessel across hidden shoals into open seas who gives the best value.

Faced with the admitted difficulty of managing the creative process, we are doubling our efforts to do so. Is this because science has failed to deliver, having given us nothing more than nuclear power, penicillin, space travel, genetic engineering, transistors, and superconductors? Or is it because governments everywhere regard as a reproach activities they cannot advantageously control? They felt that way about the marketplace for goods, but trillions of wasted dollars later, they have come to recognize the efficiency of this self-regulating system. Not so, however, with the marketplace for ideas.

I knew, however, that it would cost ten times what I had available in order to build a molecular beam machine. I decided to follow a byway, rather than the highway. It is a procedure I have subsequently recommended to beginning scientists in this country, where research strategy is best modelled on that used by Wolfe at the Plains of Abraham.
(British General James Wolfe defeated the French defending Quebec in 1759 after scaling a cliff for a surprise attack.)

Idealism is the highest form of reason.

It is folly to use as one's guide in the selection of fundamental science the criterion of utility. Not because (scientists)... despise utility. But because. .. useful outcomes are best identified after the making of discoveries, rather than before.
Concerning the allocation of research funds.

It is the constant attempt in this country [Canada] to make fundamental science responsive to the marketplace. Because technology needs science, it is tempting to require that scientific projects be justified in terms of the worth of the technology they can be expected to generate. The effect of applying this criterion is, however, to restrict science to developed fields where the links to technology are most evident. By continually looking for a short-term payoff we disqualify the sort of science that … attempts to answer fundamental questions, and, having answered them, suggests fundamentally new approaches in the realm of applications.

It takes a trained and discerning researcher to keep the goal in sight, and to detect evidence of the creeping progress toward it.

Nothing is more irredeemably irrelevant than bad science.

Science is a collection of stories, linking characters worthy of notice.

Science is an enterprise that can only flourish if it puts the truth ahead of nationality, ethnicity, class and color.

The layman, taught to revere scientists for their absolute respect for the observed facts, and for the judiciously detached and purely provisional manner in which they hold scientific theories (always ready to abandon a theory at the sight of any contradictory evidence) might well have thought that, at [Dayton C.] Miller's announcement of this overwhelming evidence of a “positive effect” [indicating that the speed of light is not independent from the motion of the observer, as Einstein's theory of relativity demands] in his presidential address to the American Physical Society on December 29th, 1925, his audience would have instantly abandoned the theory of relativity. Or, at the very least, that scientists—wont to look down from the pinnacle of their intellectual humility upon the rest of dogmatic mankind—might suspend judgment in this matter until Miller's results could be accounted for without impairing the theory of relativity. But no: by that time they had so well closed their minds to any suggestion which threatened the new rationality achieved by Einstein's world-picture, that it was almost impossible for them to think again in different terms. Little attention was paid to the experiments, the evidence being set aside in the hope that it would one day turn out to be wrong.