The sheer quantity of the advice tells a story. The three-dozen-odd rules are not independent of one another but exemplify a few themes. It’s unlikely that each of us today had to be instructed in every rule individually, so that if some mother had been remiss in teaching one of them, her adult son would still be blowing his nose into the tablecloth. The rules in the list (and many more that are not) are deducible from a few principles: Control your appetites; Delay gratification; Consider the sensibilities of others; Don’t act like a peasant; Distance yourself from your animal nature. And the penalty for these infractions was assumed to be internal: a sense of shame. Elias notes that the etiquette books rarely mention health and hygiene. Today we recognize that the emotion of disgust evolved as an unconscious defense against biological contamination. But an understanding of microbes and infection did not arrive until well into the 19th century. The only explicit rationales stated in the etiquette books are to avoid acting like a peasant or an animal and to avoid offending others.

In the European Middle Ages, sexual activity too was less discreet. People were publicly naked more often, and couples took only perfunctory measures to keep their coitus private. Prostitutes offered their services openly; in many English towns, the red-light district was called Gropecunt Lane. Men would discuss their sexual exploits with their children, and a man’s illegitimate offspring would mix with his legitimate ones. During the transition to modernity, this openness came to be frowned upon as uncouth and then as unacceptable. The change left its mark in the language.

Words for peasantry took on a second meaning as words for turpitude: boor (which originally just meant “farmer,” as in the German Bauer and Dutch boer); villain (from the French vilein, a serf or villager); churlish (from English churl, a commoner); vulgar (common, as in the term vulgate); and ignoble, not an aristocrat. Many of the words for the fraught actions and substances became taboo. Englishmen used to swear by invoking supernatural beings, as in My God! and Jesus Christ! At the start of the modern era they began to invoke sexuality and excretion, and the “Anglo-Saxon four-letter words,” as we call them today, could no longer be used in polite company As the historian Geoffrey Hughes has noted, “The days when the dandelion could be called the pissabed, a heron could be called a shitecrow and the windhover could be called the windfucker have passed away with the exuberant phallic advertisement of the codpiece.” 26Bastard, cunt, arse, and whore also passed from ordinary to taboo.