After reading and talking to Chalmers, I’ve come to believe that the coming world of virtual reality might one day be regarded as every bit as real as real reality. If that happens, our current reality will instantly be cast into doubt; after all, if we could invent meaningful virtual worlds, isn’t it plausible that some other civilization somewhere else in the universe might have done so, too? Yet if that’s possible, how could we know that we’re not already in its simulation?

The conclusion seems inescapable: We may not be able to prove that we are in a simulation, but at the very least, it will be a possibility that we can’t rule out. But it could be more than that. Chalmers argues that if we’re in a simulation, there’d be no reason to think it’s the only simulation; in the same way that lots of different computers today are running Microsoft Excel, lots of different machines might be running an instance of the simulation. If that was the case, simulated worlds would vastly outnumber non-sim worlds — meaning that, just as a matter of statistics, it would be not just possible that our world is one of the many simulations but likely. As Chalmers puts it, “We are probably sims.”