Sam Harris speaks with Rebecca Goldstein and Max Tegmark about the foundations of human knowledge and morality. Rebecca Goldstein is a MacArthur Fellow, a professor of philosophy, and the author of five novels and a collection of short stories. She lives in Boston, Massachusetts. Her latest book is Plato at The Googleplex: Why Philosophy Won’t Go Away. Twitter: @platobooktour Max Tegmark is a professor of physics at MIT and the co-founder of the Future of Life Institute. Tegmark has been featured in dozens of science documentaries. He is the author of Our Mathematical Universe and Life 3.0: Being Human in the Age of Artificial Intelligence. Twitter: @Tegmark