“Bunch together a group of people deliberately chosen for strong religious feelings, and you have a practical guarantee of dark morbidities expressed in crime, perversion, and insanity.”

Letter to Robert E. Howard, (October 4, 1930), https://books.google.com/books?id=rVERL_j9UfcC&printsec=frontcover&dq=isbn:0809515679&hl=en&sa=X&ei=-beOVeGqHsi_ggT1vqKgCw&ved=0CB4Q6AEwAA#v=onepage&q=insanity&f=true
Non-Fiction, Letters, to Robert E. Howard
Context: It is the night-black Massachusetts legendry which packs the really macabre 'kick', Here is the material for a really profound study in group neuroticism; for certainly, no one can deny the existence of a profoundly morbid streak in the Puritan imagination.... The very pre-ponderance of passionately pious men in the colony was virtually an assurance of unnatural crime; insomuch as psychology now proves the religious instinct to be a form of transmuted eroticism precisely parallel to the transmutations in other directions which respectively produce such things as sadism, hallucination, melancholia, and other mental morbidities. Bunch together a group of people deliberately chosen for strong religious feelings, and you have a practical guarantee of dark morbidities expressed in crime, perversion, and insanity. This was aggravated, of course, by the Puritan policy of rigorously suppressing all the natural outlets of excuberant feeling--music, laughter, colour, pageantry, and so on. To observe Christmas Day was once a prison offence....