The term “cancel culture,” like “political correctness” before it, is a comical expression for an ugly cultural pathology. To be canceled—an older, closely related term is “blacklisted”—is to have your public persona or influence assailed, typically by a sizable mob, for some real or perceived offense against progressive orthodoxy, whatever that orthodoxy may hold at the moment. For that to happen, you must possess some form of authority in the first place: an academic post, a political office, a role in the entertainment industry, employment with a “mainstream” media organization, a voice as an intellectual or imaginative writer. But the...