To the young I should offer two maxims: Don't accept superficial solutions of difficult problems. It is better to do a little good than much harm. I should not offer anything more specific; every young person should decide on his or her own credo.

The dictum that human nature cannot be changed is one of those tiresome platitudes that conceal from the ignorant the depths of their own ignorance.

Reason may be a small force, but it is constant, and works always in one direction, while the forces of unreason destroy one another in futile strife.

Real life is, to most men, a long second best, a perpetual compromise between the ideal and the possible.

Opinions which justify cruelty are inspired by cruel impulses.

The commonest objection to birth control is that it is against nature.

In the first place a philosophical proposition must be general. It must not deal specially with things on the surface of the earth, or within the solar system, or with any other portion of space and time. . . . This brings us to a second characteristic of philosophical propositions, namely that they must be a priori. A philosophical proposition must be such as can neither be proved nor disproved by empirical evidence. . . . Philosophy, if what has been said is correct, becomes indistinguishable from logic as that word has now come to be used.