In the 18th century, French architect Claude-Nicolas Ledoux conceived an ideal city — perhaps too ideal. It contained no hospitals or theaters but included a “shelter of the poor man,” a “Pacifère” where quarrels could be settled peaceably, and, most notably, an “Oïkéma,” or house of sexual instruction, which Allan Braham calls “one of the most extreme instances of Ledoux’s gift for architectural metaphor.” While we’re on this subject: In William Wycherley’s 1675 comedy The Country Wife, the word china becomes a bawdy metaphor, which makes the dialogue livelier than it first appears: Lady Fidget: And I have been toiling...