C.G. Jung, Modern Man in Search of a Soul

"Is that which science calls the “psyche” not merely a question-mark arbitrarily confined within the skull, but rather a door that opens upon the human world from a world beyond, now and again allowing strange and unseizable potencies to act upon him and to remove him, as if upon the wings of the night, from the level of common humanity to that of a more personal vocation?"

"I have treated many hundreds of patients. Among those in the second half of life - that is to say, over 35 - there has not been one whose problem in the last resort was not that of finding a religious outlook on life. It is safe to say that every one of them fell ill because he had lost that which the living religions of every age have given their followers, and none of them has really been healed who did not regain his religious outlook."