Jim Holt is a philosopher, author and essayist. He has contributed to the New York Times, New York Times Magazine, New York Review of Books, New Yorker, American Scholar, and Slate. He hosted a weekly radio spot on BBC Wales called "Living in America, with Jim Holt" and has appeared on William F. Buckley's Firing Line, NBC News with Tom Brokaw, and CNN. He was editor of The New Leader, a political magazine. His book Why Does the World Exist? was a 2012 New York Times Top 10 Book of the Year and a Slate.com 2012 Staff Pick. In it he traced the riddle of existence from the ancient world to modern times. Holt has also written a history of jokes: Stop Me If You've Heard This: A History and Philosophy of Jokes.