Note: "The Screwtape Letters" is a piece of satire, written as if from the perspective of a senior demon enlightening a junior demon about the areas in which human "patients" can be most easily tempted.
“Humour is for them the all consoling and (mark this) the all-excusing grace of life. Hence it is invaluable as a means of destroying shame. If a man simply lets others pay for him, he is ‘mean;’ if he boasts of it in a jocular manner and twits his fellows with having been scored off, he is no longer ‘mean’ but a comical fellow. Mere cowardice is shameful; cowardice boasted of with humourous exaggerations and grotesque gestures can be passed off as funny. Cruelty is shameful—unless the cruel man can represent it as a practical joke… And this temptation can be almost entirely hidden from your patient by that English seriousness about Humour. Any suggestion that there might be too much of it can be represented to him as ‘Puritanical’ or as betraying a ‘lack of humour’!”
- Screwtape, (HarperCollins, 2001, pp. 55-56)