If only the fit survive and if the fitter they are the longer they survive, then Volvox must have demonstrated its superb fitness more conclusively than any higher animal ever has.

When, in the present world, men behave well, that is no doubt sometimes because they are creatures of habit as well as, sometimes, because they are reasonable.

The most important part of our lives-our sensations, emotions, desires, and aspirations-takes place in a universe of illusions which science can attenuate or destroy, but which it is powerless to enrich.

We have not merely escaped from something but into something... We have joined the greatest of all communities, which is not that of man alone but of everything which shares with us the great adventure of being alive.

Poetry, mythology, and religion represent the world as man would like to have it, while science represents the world as he gradually comes to discover it.

Not to have known - as most men have not - either the mountain or the desert is not to have known one's self. Not to have known one's self is to have known no one.

Though we face the facts of sex we are more reluctant than ever to face the fact of death or the crueler facts of life, either biological or social.