David Edmonds is an award-winning documentary maker for the BBC World Service. He is the author or co-author (with John Eidinow) of several books, including Wittgenstein's Poker (short-listed for the Guardian First Book Award), Bobby Fischer Goes To War (long-listed for the Samuel Johnson prize), and Rousseau's Dog (about the relationship between Jean-Jacques Rousseau and David Hume). He is currently a Research Associate at the Uehiro Centre for Practical Ethics at Oxford University and an Associate Editor for Prospect Magazine. Nigel Warburton is a freelance philosopher, podcaster, and writer. His books include A Little History of Philosophy, Philosophy: the Basics, Thinking from A to Z, Philosophy: the Classics, The Art Question, and Free Speech: A Very Short Introduction. He runs several weblogs including virtualphilosopher.com and artandallusion.com, and tweets regularly at @philosophybites.