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.

Man can alter his life by altering his thinking.

The most immutable barrier in nature is between one man's thoughts and another's.

The true is the name of whatever proves itself to be good in the way of belief, and good, too, for definite, assignable reasons.

The deepest human need is the need to be appreciated.

When you have broken the reality into concepts you never can reconstruct it in its wholeness.

Our theories are wedged and controlled as nothing else is. Yet sometimes alternative theoretic formulas are equally compatible with all the truths we know, and then we choose between them for subjective reasons. We choose the kind of theory to which we are already partial: we follow 'elegenace' or 'economy'