The challenge to a theoretical physicist pushing beyond our best current theories is that there are too many ways to go. What parts of the existing paradigm do you keep, which do you discard, and why make those choices? Among today’s theorists, Lee Smolin is unusually reflective about what principles should guide us in the construction of new theories. And he is happy to suggest radical revisions to well-established ideas, in areas from the nature of time to the workings of quantum mechanics. We talk about time, the universe, the role of philosophy, a new picture of spacetime, and the future of physics. Lee Smolin received his Ph.D. in physics from Harvard University. He is currently on the faculty of the Perimeter Institute in Waterloo, Canada, where he was a founding member. Among his awards are the Majorana Prize, the Klopsteg Memorial Award, and the Buchalter Cosmology Prize. He is the author of several books, most recently Einstein’s Unfinished Revolution: The Search for What Lies Beyond the Quantum.