Napping is too luxurious, too sybaritic, too unproductive, and it's free; pleasures for which we don't pay make us anxious. Besides, it seems to be a natural inclination.... Fighting off natural inclinations is a major Puritan virtue, and nothing that feels that good can be respectable.
Endangered Pleasures: In Defense of Naps, Bacon, Martinis, Profanity, and Other Indulgences (1995)