Science, by itself, cannot supply us with an ethic. It can show us how to achieve a given end, and it may show us that some ends cannot be achieved. But among ends that can be achieved our choice must be decided by other than purely scientific considerations. If a man were to say, "I hate the human race, and I think it would be a good thing if it were exterminated," we could say, "Well, my dear sir, let us begin the process with you." But this is hardly argument, and no amount of science could prove such a man mistaken.

Advocates of capitalism are very apt to appeal to the sacred principles of liberty, which are embodied in one maxim: The fortunate must not be restrained in the exercise of tyranny over the unfortunate.

Among the Tibetans, one wife has many husbands, because men are too poor to support a whole wife.

For love of domination we must substitute equality; for love of victory we must substitute justice; for brutality we must substitute intelligence; for competition we must substitute cooperation. We must learn to think of the human race as one family.

The root of the matter is a very simple and old fashioned thing... love or compassion. If you feel this, you have a motive for existence, a guide for action, a reason for courage, an imperative necessity for intellectual honesty.

Logic must no more admit a unicorn than zoology can.

When one admits that nothing is certain one must, I think, also admit that some things are much more nearly certain than others.