John West, what are your thoughts on Digital Physics?

By the way, I did read the paper. I was wondering if "I have hands" could still be true under SH.

John West wrote:

I don't know much about it. I don't think that the world is reducible to mathematics (i.e. the output of a computer program) though, if that is what you're asking. Do you?

I don't think so either, but the fact that it is possible to model the world like a video game (for example, to model space as pixilated and model reality as being created by observation) seems suspicious. I'm not saying reality is actually any of these things, just that it is possible to model them like that. Perhaps a Bayesian argument could be made: If reality is virtual, we would expect to be able to model reality in those ways.

John West, do you think one could deny being a simulated person (NOT a brain in vat) by saying "I have two hands"? In other words, are ones knowledge of ones hands are incompatible with being a simulated person?

For example, maybe substantial and accidental forms could exist in a simulation, and we perceive these forms in sensory experience. Perhaps, if the computer is a parallel processor, forms, space and volume could still exist?

A few comments if we are "brains in vats":

1) Some things cannot be reduced to mere simulation. Self-evident principles would still be self-evident. And we would still be certain of everything reducible to self-evident principles. Thus, theism, for example, is untouched.

2) Christianity and all religions would just be a simulation (by definition).

3) I am convinced that free choice is self-evident. And, that there is something about free choice and consciousness and the operation of the intellect that cannot be reduced to purely material causes. Thus, on my reckoning, absolute determinism and materialism are false. Thus, if I am a brain in a vat, I am not merely a brain in a vat.

4) We already have a good analogy to this brain-in-a-vat situation that we all experience: dreaming/hallucination. It is possible to experience a dream and think it is real. So it doesn't seem possible to a priori exclude the possibility of some aspects of our wakeful state itself being something like sleep compared to...I don't know...some higher state of consciousness that we haven't awoken to?

5) Regarding #4, I think we find something like this already expressed in Christian Theology? That this life is like a dream/sleep compared with the afterlife? That the next life is more real? In our "childhood" we live in make-believe but then we grow up? "For we know in part, and we prophesy in part. But when that which is perfect is come, that which is in part shall be done away. When I was a child, I spoke as a child, I understood as a child, I thought as a child. But, when I became a man, I put away the things of a child. We see now through a glass in a dark manner; but then face to face. Now I know in part; but then I shall know even as I am known" (1 Corin. 13:9-12).

6) If, per #1, theism could still be proven true, then perhaps one could argue that God, being Truth Itself, could not allow such a thorough deception of being brains in vats? Just food for thought...

7) If we are indeed brains in vats, then our actions in the simulation have no more moral significance than our actions in a video game. But, it seems that the most that can be said is that "brain-in-vat" is a hypothetical possibility, not that it is a certainty. If so, then I would argue that morality (considered subjectively at least) remains unchanged. If one is uncertain whether "reality" is real, then one should err on the safe side. Thus, unless one is certain that we are brains in vats, it would be immoral to act as if we are so.