Boys and girls should be taught respect for each other's liberty... and that jealousy and possessiveness kill love.

The life of man is a long march through the night, surrounded by invisible foes, tortured by weariness and pain, towards a goal that few can hope to reach, and where none may tarry long.

Zeno was concerned with three problems... These are the problem of the infinitesimal, the infinite, and continuity.

The scientific attitude of mind involves a sweeping away of all other desires in the interest of the desire to know.

Even if we could be certain that one of the world's religions were perfectly true, given the sheer number of conflicting faiths on offer, every believer should expect damnation purely as a matter of probability.

Remember your humanity, and forget the rest.

I do not believe that I am now dreaming, but I cannot prove that I am not.