The principal difference between love and hate is that love is a irradiation, and hate is a concentration. Love makes everything lovely; hate concentrates itself on the object of its hatred.

The whole purpose of education is to turn mirrors into windows.

We must become masters of our own actions and attitudes. To let another person determine whether we will be rude or gracious, elated or depressed is to give control of ourselves. The only true possession is self possession.

Good teaching must be slow enough so that it is not confusing, and fast enough so that it is not boring.

Honesty consists of the unwillingness to lie to others; maturity, which is equally hard to attain, consists of the unwillingness to lie to oneself.

Why are we willing to accept a new mathematical formula we don't understand as the product of a brilliant mind, while rejecting a new art form we don't understand as the product of a deranged mind?

The deepest and rarest kind of courage has nothing to do with feats or obstacles in the outside world; and, indeed, has nothing to do with the outside world - it is the courage to be who you are.