“When one teaches, two learn.”

“Never attempt to teach a pig to sing; it wastes your time and annoys the pig.”

“Writing can be learned, but not taught.”

“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.”

“One man’s “magic” is another man’s engineering. “Supernatural” is a null word.”

“when faced with a problem you do not understand, do any part of it you do understand, then look at it again.”

“It is impossible for anyone to be responsible for another person's behavior. The most you or any leader can do is to encourage each one to be responsible for himself.”