We have the means to make some of the most complex and dangerous work we do—in surgery, emergency care, ICU medicine, and beyond—more effective than we ever thought possible. But the prospect pushes against the traditional culture of medicine, with its central belief that in situations of high risk and complexity what you want is a kind of expert audacity—the right stuff, again. Checklists and standard operating procedures feel like exactly the opposite, and that’s what rankles many people.