On Thu, Dec 29, 2011 at 05:47:07PM +0100, Bruno Marchal wrote: > > On 28 Dec 2011, at 22:21, Russell Standish wrote: > > > >They both cannot supervene on the same physical state. > > In my weak sense, they both supervene on the same physical state of > the room, or universe, or even arithmetic.
We're not talking about your weak sense, but the standard definition of supervenience. > > > > >That is > >by the definition of supervenience. > > The intuitive definition of supervenience is that A supervenes on B > if we cannot have an A-difference without a B-difference. Yes. > If A supervenes on B, it supervene trivially on a disjoint union of > B and C, because we still cannot have an A-difference without a (B > union C difference). > No - the Tommy vs Samantha example is a counter example: Let T sup B and S sup C. But T and C are different conscious states, so cannot both supervene on B u C. > > > >Therefore they both cannot > >supervene on the same classroom. > > In that case I would have said that Tommy's consciousness supervenes > *only* on Tommy's brain (but I avoid this because we don't know and > cannot know what is our real "generalized brain"). > Whatever the "generalised brains" are, the foregoing discussion implies that the intersection of two "generalised brains" must be empty. > > > > >Perhaps the word swapping is misleading to you - I didn't mean > >anything particularly profound by it. > > I have still no idea of what you mean by that. Suppose that you tell > me that Bruno and Russell's consciousness swap every minutes, since > six months. What would that mean? I don't see how we could be aware > of such things, nor how we could verify this in any third (and > first) person way. Nor do I. Not even a putative God could be aware, I would think. I wasn't suggesting such a thing, anyway. I was thinking more in terms of first consider Tommy's consiousness then afterwards think of Samantha's. Thus you are swapping the focus of your attention. > And this makes your argument (physicalist, for > the sake of the reasoning) against the consciousness instantiated by > the (concrete) UD dubious. I think. I mean that this critics on MGA > fails, at least by lack of clarity (for me). > The critique was against your step of unfolding the multiverse into a single universe by dovetailing. You then asserted that the consciousness supervened on the dovetailer, which as we've been through above, cannot be the case. Of course, you may refine your argument by dovetailing just the "generalised brain", and not its environment which contains other "brains". But in this case, I would point out that eliminating the environment may well render the "brain" unconsious. There is certainly evidence from sensory depreivation experiments that this might happen. Or maybe you have a different way of emulating a multiverse without dovetailing? Cheers -- ---------------------------------------------------------------------------- Prof Russell Standish Phone 0425 253119 (mobile) Principal, High Performance Coders Visiting Professor of Mathematics hpco...@hpcoders.com.au University of New South Wales http://www.hpcoders.com.au ---------------------------------------------------------------------------- -- You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to everything-list@googlegroups.com. To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/everything-list?hl=en.
