John Locke invented common sense, and only Englishmen have had it ever since!

One of the painful things about our time is that those who feel certainty are stupid, and those with any imagination and understanding are filled with doubt and indecision.

The world is full of magical things patiently waiting for our wits to grow sharper.

I have come to realize that an early symptom of approaching mental illness is the belief that one's work is terribly important. If you consider your work very important you should take a day off.

Teachers are more than any other group the guardians of civilization.

It is not what the man of science believes that distinguishes him, but how and why he believes it. His beliefs are tentative, not dogmatic; they are based on evidence, not on authority or intuition.

Machines have altered our way of life, but not our instincts. Consequently, there is maladjustment.