Hi Gilles, thanks for your detailed reply. I want to precise some point.
You wrote :
>I do not take the Universe for granted. I think
>our discourse about the world is subjective and that any proposition about
>its real nature (I put in this category God, the Big programmer or N !) is
>desperately devoid of usefulness, because not testable and not falsifiable.
I think that if COMP is true, we cannot prove it. Nevertheless,
I think that if COMP is false, it is refutable.
Remember I give argument for saying that eventually we will be able to
derive (part of) physics from comp. And we will be able to compare
"introspective discoveries" with the "seemingly empirical".
Of course you are right to doubt the very possibility of this. When you
>However I do not know any example where ontological reflexions have allowed
>to make anything real. Furthermore we may have different "epistemological"
>points of view.
May be you are right. May be not. I suggest you read the marvelous little
book by Marc Steiner (1998) "The applicability of mathematics as a
philosophical problem" (Harvard Press). It is a startling defense of
anthropomorphism based on the developpement of the mathematical formalism
If you replace "human" by "universal turing machine" you will be very
near the spirit of my approach. I am a "Universal-machine-morphist" in
some way. I don't put human at the center of the universe, but I put
people there, people in the most general, although non trivial, sense
made possible by Church's Thesis.
> For example a very important step would be to succeed in building
>"thinking machines", say like Turing, machines which you could discuss
>with. I think this step is feasible. What I think is that they will never
>be used to "replace" somebody, first because it is tremendously more
>complicated to duplicate (and as I tried to convince you, impossible to
>duplicate *exactly*) a highly organized system that to let a simple one
>self-organize (what nature has made for all of us), and second because it
>will raise so difficult questions about identity that we would promptly
>abandon this way! So most probably such machines would be like a new,
>artificial (living??) species with its own individuals, all different from
>each others (because I think that consciousness can exist only with a
>personal history) and of course from us. This is hopefully a testable
If you are willing to admit consciousness for these machines, you can do
my thought experiments with these machines. Even if you think these
machines are no more duplicable in practice (for complexity reason), you
know they are duplicable in principle. We need no more for the reasoning.