> You actually can't prove _anybody else in the world_ besides you has a first person subjective experience. That's absolutely true. My wife and I sometimes jo

> You actually can't prove _anybody else in the world_ besides you has a first person subjective experience. That's absolutely true. My wife and I sometimes joke that each of us is an incorporeal figment in the other's dream. It's impossible for me to know with certainty that I am not the only real consciousness in existence. It's an interesting line of thought, but ultimately unproductive; what could I do if it's true? If it's not, then the validity of all of the other consciousnesses is just as pressing as mine. Either way it behooves me to behave as though it is true, so I suppose that's the starting point for all of my thoughts on this topic: I and all other humans have a first person subjective experience. I agree with (parent? gp?) that describing the nature of that experience is non-trivial.