The root of the matter is a very simple and old fashioned thing... love or compassion. If you feel this, you have a motive for existence, a guide for action, a reason for courage, an imperative necessity for intellectual honesty.

Remember your humanity, and forget the rest.

... mathematical knowledge ... is, in fact, merely verbal knowledge. "3" means "2+1", and "4" means "3+1". Hence it follows (though the proof is long) that "4" means the same as "2+2". Thus mathematical knowledge ceases to be mysterious.

The average man's opinions are much less foolish than they would be if he thought for himself.

What is wanted is not the will to believe, but the will to find out, which is the exact opposite.

Ideas and principles that do harm are as a rule, though not always, cloaks for evil passions.

When I was a child . . . Only virtue was prized, virtue at the expense of intellect, health, happiness, and every mundane good.