I first encountered Lawrence Krauss sometime in the early 2000s at a conference. I had just given my lecture and was answering questions when a rather small man with a loud voice and a highly articulate manner stood up and began berating me in what I initially thought was an aggressive manner. It turned out he wasn’t being aggressive; rather, his clear and direct way of speaking seemed forceful compared to the usual, more roundabout way people talk. Intrigued, I sought him out in the bar afterward, and we had a good discussion. This man was, of course, the distinguished physicist and public intellectual Lawrence Krauss. Shortly afterward, we continued our friendly disagreement in the pages of Scientific American, back when the publication still focused on science. Since then, I’ve interacted with Lawrence on stage more often than with anyone else. The following recording was made at Stanford University around 2007 and exemplifies how two people can have a fruitful public discussion without a chairman and outside of a debate format. The nature of our initial disagreement forms a good part of the discussion itself, so I won’t spoil it here. I hope you enjoy it.