Sam Harris speaks with David Deutsch about his book, The Beginning of Infinity. They discuss the boundary between science and philosophy, the nature of scientific authority, the utility of knowledge, artificial intelligence, moral relativism, the Fermi problem, and other topics.  David Deutsch is best known as the founding father of the quantum theory of computation, and for his work on Everettian (multiverse) quantum theory. He is a Visiting Professor of Physics at Oxford University, where he works on “anything fundamental.” At present, that mainly means his proposed constructor theory. He has written two books – The Fabric of Reality and The Beginning of Infinity – aimed at the general reader.   Episodes that have been re-released as part of the Best of Making Sense series may have been edited for relevance since their original airing.