Behind every mystery lies another mystery.

Don't ever become a pessimist... a pessimist is correct oftener than an optimist, but an optimist has more fun, and neither can stop the march of events.

Ignorance is curable, stupid is forever.

Obscurity is the refuge of incompetence.

Many short-sighted fools think that going to the Moon was just a stunt. But the astronauts knew the meaning of what they were doing, as is shown by Neil Armstrong's first words in stepping down onto the soil of Luna: "One small step for a man, one giant leap for mankind."

If we blow ourselves up we will do it by misapplication of science; if we manage to keep from blowing ourselves up, it will be through intelligent application of science.

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.