The dog [in Pavlov's experiments] does not continue to salivate whenever it hears a bell unless sometimes at least an edible offering accompanies the bell. But there are innumerable instances in human life where a single association, never reinforced, results in the establishment of a life-long dynamic system. An experience associated only once with a bereavement, an accident, or a battle, may become the center of a permanent phobia or complex, not in the least dependent on a recurrence of the original shock.

Prejudgments become prejudices only if they are not reversible when exposed to new knowledge.

Each person is an idiom unto himself, an apparent violation of the syntax of the species.

If a person is capable of rectifying his erroneous judgments in the light of new evidence he is not prejudiced. Prejudgments become prejudices only if they are reversible when exposed to new knowledge. A prejudice, unlike a simple misconception, is actively resistant to all evidence that would unseat it. We tend to grow emotional when a prejudice is threatened with contradiction. Thus the difference between ordinary prejudgments and prejudice is that one can discuss and rectify a prejudgment without emotional resistance.

Love received and love given comprise the best form of therapy.

The mature religious sentiment is ordinarily fashioned in the workshop of doubt.

If there is a purpose in life at all, there must be a purpose in suffering and in dying. But no man can tell another what this purpose is. Each must find out for himself, and must accept the responsibility that his answer prescribes. If he succeeds he will continue to grow in spite of all indignities.