In thirty years I have treated many patients. Among all my patients in the second half of life, every one of them fell ill because he had lost that which the living religions of every age had given their followers, and none of them was really healed who did not regain his religious outlook.

The angels are a strange genus: they are precisely what they are and cannot be anything else. They are in themselves soulless beings who represent nothing but the thoughts and intuitions of their Lord.

There is no such thing as a pure extrovert or a pure introvert. Such a man would be in the lunatic asylum.

The gods have become our diseases.

An understanding heart is everything in a teacher, and cannot be esteemed highly enough.

Nothing has a stronger influence psychologically on their environment and especially on their children than the unlived life of the parent.

New ideas are not only the enemies of old ones; they also appear often in an extremely unacceptable form.