I once asked Shelby Foote, the author of the celebrated Civil War trilogy, to comment on the qualities of a good writer.
“There’s a high intelligence in a good writer,” he said. “It might not take the form of having any business sense and so forth, but he knows what he’s doing, and he’s got an acuteness of observation that can only come from intelligence. Faulkner was a highly intelligent man. It sounds silly to say it. But people pay no attention to it.
“And a dumb fellow, a fellow who was pretty thick in the head, like Thomas Wolfe, he pays a big price for that lack of intelligence. It keeps him from being Faulkner.”