If a man cannot do brain work without stimulants of any kind, he had better turn to hand work it is an indication on Nature's part that she did not mean him to be a head worker.

Without seeing any reason to believe that women are, on the average, so strong physically, intellectually, or morally, as men, I cannot shut my eyes to the fact that many women are much better endowed in all these respects than many men, and I am at a loss to understand on what grounds of justice or public policy a career which is open to the weakest and most foolish of the male sex should be forcibly closed to women of vigor and capacity.

My fundamental axiom of speculative philosophy is that materialism and spiritualism are opposite poles of the same absurdity-the absurdity of imagining that we know anything about either spirit or matter.

Only a scientific people can survive in a scientific future.

... our "Physick" and "Anatomy" have embraced such infinite varieties of being, have laid open such new worlds in time and space, have grappled, not unsuccessfully, with such complex problems, that the eyes of Vesalius and of Harvey might be dazzled by the sight of the tree that has grown out of their grain of mustard seed.

Friendship involves many things but, above all the power of going outside oneself and appreciating what is noble and loving in another.

. . . I fail to find a trace [in Protestantism] of any desire to set reason free. The most that can be discovered is a proposal to change masters. From being a slave of the papacy, the intellect was to become the serf of the Bible.