Former Federal Reserve chairman Ben Bernanke’s new book feels more like the first of many acts than an authoritative memoir. And the main body of the narrative remains, so far as financial history is concerned, very much a work in progress.

Still, notwithstanding its provisional character, there’s no denying that The Courage to Act is a useful document. Bernanke was arguably the most powerful economic official in the world during the worst global financial crisis since the Great Depression. His direct account of that event, staid though it can be, is invaluable—both for the official record