“There are genres whose principal business is fact—journalism, history, popular science—but the essay has never been one of them. If the form possesses a defining characteristic, it is that the essay makes an argument (and does so, unlike academic writing and other forms, for a general rather than a specialized audience). That argument can rest on fact, but it can also rest on anecdote, or introspection, or cultural interpretation, or some combination of all these and more. There are “public essays” and “personal essays” and essays that are both or neither; the form is broad and various and limitlessly flexible. Yet what distinguishes an op‑ed, for instance, from a news report is that the former seeks to persuade, not simply inform.”