American Artists don’t have to be licensed—a good thing, that—but they do tend to be credentialed. The art world is bristling with degrees from Yale and Cal Arts and hundreds of other academies. In that world, Thornton Dial stands out. He has no formal training and very little schooling of any kind. To be blunt, he can’t read or write. But sometime during his long years as a metalworker in Alabama, he turned to making what he at first simply called “things,” because it would be a long time before he, or anybody else, realized that those things are better described as art. And not just that, but some of the most assured, delightful and powerful art around.