A great idea goes through three stages on its way to acceptance: 1) it is dismissed as nonsense, 2) it is acknowledged as true, but insignificant, 3) finally, it is seen to be important, but not really anything new.

The worst thing that can happen to a good teacher is to get a bad conscience about her profession because she feels herself hopeless as a psychologist.

There is no more miserable human being than one in whom nothing is habitual but indecision, and for whom the lighting of every cigar, the drinking of every cup, the time of rising and going to bed every day, and the beginning of every bit of work, are subjects of express volitional deliberation.

The most peculiar social self which one is apt to have is in the mind of the person one is in love with.

If you can change your mind, you can change your life.

Habit is the enormous flywheel of society, its most precious conservative agent. There is no more miserable human being than one in whom nothing is habitual but indecision. Full half the time of such a man goes to the deciding, or regretting, of matters which ought to be so ingrained in him as practically not to exist for his consciousness at all.

... no bell in us tolls to let us know for certain when truth is in our grasp.