Hour 2: He’s famous for both his incredible art and his notorious instability, but what was life really like for one of the greatest artists in history? We’ll spend this hour with Pulitzer prize-winning author Steven Naifeh. His new book, co-written with Gregory White Smith is “Van Gogh: The Life” (Random House, 2011). Both Naifeh and Smith will speak this evening at Arts & Letters Live at the Dallas Museum of Art.