The philosopher David Chalmers has an interesting article on the philosophy of the Matrix, which you can download here. In case you haven’t seen the movie, the premise is that in the future machines have taken over the earth and they use humans as an energy source. The humans are housed in these pods and to keep them entertained, they’re minds are connected to “the Matrix” where they believe they live in a turn of the (21st) century world. My very first blog post was on how the energy source premise was inconsistent thermodynamically.
Chalmers points out an interesting conundrum for people living in the Matrix. Given that the simulation is completely realistic then the simulated bodies in the Matrix should function like real bodies. If that is the case then what do the simulated brains do? Are they an exact replica of the real brains in the pods? If the simulated brains controlled the simulated bodies then what do the pod brains do? Are they just spectators? Chalmers posits that the outputs of the two brains could be averaged to control the Matrix bodies. It seems to me that if the pod brains have some control of the simulated body then it would be possible for the simulated humans to do an experiment to show that their brains in the simulation are not completely responsible for controlling their bodies or for their conscious experience. They could then empirically deduce that they live in a dualistic world where mind is not exactly the same as brain. This is unlike a self-contained simulation where the simulated brains control simulated bodies entirely. In that situation, you could not tell if you lived in a simulation.