David Nyman wrote: > 1Z wrote: > > > Whatever properties are picked out by a computation > > will be relevant to it as a computation. > > Yes, of course. But how are these properties supposed to simultaneously > produce a state of consciousness stably linked to the 'computation' > when this self-same computation could have been instantiated in > arbitrarily many physically distinct ways?
Why not? A ordinary numerical computation can be instantiated in arbitrarily many physical ways, and still produce the same result. > The computations would be > equivalent, but you appear to be claiming that however they are > implemented, arbitrarily many distinct physical properties somehow > become equally 'relevant' to generating the same state of > consciousness. I still don't see why you think this is a problem. If different physical states always produced different mental states, there would be no mental commonalities between people, since all brains are physcially different. Mutiple realisability is a feature, not a bug! > > There is no requirement that > > the same connscious state is implemented > > by the same physical state, so the multiple > > reliasability of computations is not a problem > > So you say, but just *what* physical properties are supposed to be > relevant and *how* do they contrive always to manifest equivalently > within totally different implementations of a computation? How do they for a non-conscious computation? That is no a mystery, it is computer engineering. > Is this just > supposed to be a mystery? The mystery is which computations are conscious. > My point is that under materialism, > 'computation' is just a metaphor and what is directly relevant is the > activity of the physical substrate in producing the results that we > interpret in this way. Under physicalism, *all* the activity is relevant. Under computationalism, a subset is. > What's critical to computational equivalence is > not the internal states of the physical substrate, but the consistency > of the externalised results thus produced. That's a broad definition of equivalence. Running the same algorithm -- rather than producing the same results -- is generally more relevant. > But with consciousness, it's precisely the internal states that are > relevant. Yes. > And here your reasoning appears to become circular - a > particular set of physical properties can be construed as > 'externalising' a particular set of computational results at a given > point in time (fair enough) so, whatever these properties happen to be, > they're must also be 'relevant' in generating a specific internal > conscious state - and so must any arbitrary alternative set of > properties that externalise the same computational results. Only > because you say so, AFAICS. It's a claim of computationalism. I am just explaining how computationalism is compatible with physicalism. You are complaining about circularity, not contradiction! It's not an argument that computationalism is actually true, nor meant to be. > By making the rationale for supervention of > consciousness on physical activity completely arbitrary in this way It's not completely arbitrary. I don't subsribe to the idea that every physical system implements every computation. I don't even think computer-like systems are particularly common. > (it > just *somehow* tracks a 'computation' however instantiated), you've > effectively abandoned it as a materialist explanation. Didn't > Hofstadter use this sleight of intuition to conjure consciousness from > anthills and books - or was he perhaps just joking? Well, there *may* be too much multiple realisability. But remember that I have a narrowish view of what is a computer. And remember that consciousness is not held to be any old computation. --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~----------~----~----~----~------~----~------~--~---
