Even if the open windows of science at first make us shiver after the cozy indoor warmth of traditional humanizing myths, in the end the fresh air brings vigor, and the great spaces have a splendor of their own.

Every living thing is a sort of imperialist, seeking to transform as much as possible of its environment into itself.

Frege has the merit of ... finding a third assertion by recognising the world of logic which is neither mental nor physical.

But as the work proceeded I was continually reminded of the fable about the elephant and the tortoise. Having constructed an elephant upon which the mathematical world could rest, I found the elephant tottering, and proceeded to construct a tortoise to keep the elephant from falling. But the tortoise was not more secure than the elephant, and after some twenty years of very arduous toil, I came to the conclusion that there was nothing more that I could do in the way of making mathematical knowledge indubitable.

Next to worry probably one of the most potent causes of unhappiness is envy.

The first essential character [of civilization], I should say, is forethought. This, indeed, is what mainly distinguishes men from brutes and adults from children.

If you question any candid person who is no longer young, he is very likely to tell you that, having tasted life in this world, he has no wish to begin again as a "new boy" in another.