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.

The pleasure of work is open to anyone who can develop some specialised skill, provided that he can get satisfaction from the exercise of his skill without demanding universal applause.

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

Life and hope for the world are to be found only in the deeds of love.

It will be said that the joy of mental adventure must be rare, that there are few who can appreciate it, and that ordinary education can take no account of so aristocratic a good. I do not believe this. The joy of mental adventure is far commoner in the young than in grown men and women. ...It is rare in later life because everything is done to kill it during education.

Mathematics is only the art of saying the same thing in different words.

Inferences of Science and Common Sense differ from those of deductive logic and mathematics in a very important respect, namely, when the premises are true and the reasoning correct, the conclusion is only probable.