With rapid advances in Virtual Reality technology and the like, it’s now possible for us to become absorbed in completely made-up worlds. We might wonder how soon it will be till we reach a point where VR is so good, we can’t tell it apart from the real world. But what if we’ve already reached that point? How would we know if we were currently living in a simulated reality, or are there always telltale signs? And if we were in a simulation, what difference would it make—pragmatically or morally—in how we live our lives and treat other people? Josh and Ray don’t fake it with David Chalmers from NYU, author of Reality+: Virtual Worlds and the Problems of Philosophy.