A Syracuse University professor returned to national television Tuesday to share some insights into his writing process for a new book. George Saunders appeared on “The Late Show with Stephen Colbert” for the fourth time to promote “Vigil,” his latest novel. Stephen Colbert compared it to “Lincoln at the Bardo,” Saunders’ Man Booker Prize-winning book, in featuring ghosts and the afterlife again. “In the beginning, I don’t think you should know what you’re trying to do. He received a MacArthur Fellowship in 2006, has had a dozen books appear on The New York York Times bestsellers list, and is having “Lincoln in the Bardo” adapted into an opera.