Please don't invent a debt that does not exist, or next you will be trying to feel gratitude - and that is the treacherous first step toward complete moral degradation.

Anyone who cannot cope with mathematics is not fully human. At best, he is a tolerable subhuman who has learned to wear his shoes, bathe, and not make messes in the house.

I have spent too much of my life opening doors for cats—I once calculated that, since the dawn of civilization, nine hundred and seventy-eight man-centuries have been used up that way. I could show you figures.

Never appeal to a man's 'better nature.' He may not have one. Invoking his self-interest gives you more leverage.

A community where everyone is a ruthless murderer, with handy access to death-dealing devices, is a very polite community.

There is no conclusive evidence of life after death, but there is no evidence of any sort against it. Soon enough you will know, so why fret about it?

The difference between science and the fuzzy subjects is that science requires reasoning while those other subjects merely require scholarship.