The man of science is a poor philosopher.

Only the one who does not question is safe from making a mistake.

Intellectual growth should commence at birth and cease only at death.

It is difficult even to attach a precise meaning to the term "scientific truth." So different is the meaning of the word "truth" according to whether we are dealing with a fact of experience, a mathematical proposition or a scientific theory. "Religious truth" conveys nothing clear to me at all.

Betterment of conditions the world over is not essentially dependent on scientific knowledge but on the fulfillment of human traditions and ideals.

Perfection of means and confusion of goals seem to characterize our age. If we desire sincerely and passionately the safety, the welfare and the free development of the talents of all men, we shall not be in want of the means to approach such a state.

I refuse to engage in an intellectual battle with an unarmed man.