As a professional rhetorician and teacher of rhetoric—the art of persuasion—for over 35 years, I have seen a lot of bad arguments. And not all of them have come from my college students. Not by a long shot. But in all that time, the worst argument I have ever heard, by far, is this one: “If it only saves one life….” It’s a line big-government types love to trot out whenever they want good-hearted, well-meaning people to accept some sketchy, illogical, oppressive measure because, you know, it just might save one person’s life. An example is socialized medicine, which would...