On 23 August 2014 05:02, meekerdb <meeke...@verizon.net> wrote: *What we observe in practice are physical devices of various kinds (indeed, in principle, indefinitely many kinds) that we accept FAPP as adequately instantiating particular classes of computation within certain fairly stringent limits.*
*What we observe, aside from observing our own thoughts and maybe even then, is always theory laden. Partly we see the world through a theory of objects that evolution has provided us, sort of naive physics, but a theory nonetheless as optical illusions demonstrate.* And the relevance of this remark to my point is what, precisely? *To put it another way, we are prepared to interpret the normal physical behaviour of such devices *as if* it instantiated the mathematical notion of computation.* *Right, because it usually (modulo a dropped bit or so) does.* Obviously. And your point is...? *These considerations should make it clear that any description of the normal behaviour of a physical device as computation can only be in a sense that is, ultimately, metaphorical.* *I think you are too hung up on ontology. You denigrate everything that's not in terms of the ur-stuff of (some unknown) true ontology as metaphor or fiction. Why not accept that knowledge, including knowledge of ontology, is always provisional and uncertain and it's best to think of it as a model summarizing our best idea - but not necessarily the one TRUE idea.* Maybe you are getting a little too hung up on what you imagine me to be hung up on. If that is the case, it might make you somewhat unreceptive at the outset to what you assume to be my line of argument. I'm not trying to grind any axe in particular but only to articulate what I suspect are sometimes unrecognised assumptions as clearly as I can and then examine the consequences. Of course I may well be wrong on any point and so my aim is to encourage discussion from which I might learn. In this particular case what I'm driving at isn't that either matter or computation need be considered as some kind of mystical "ur-stuff" (whatever that would be). What I'm questioning is whether it is really coherent to attribute *first-person* consciousness to "computation" against the background of any theory that is committed to a physically primitive level of explanation. I know you cross swords with Bruno over the meaning of primitive in this context, but I don't see why this has to be problematic. Primitive simply means the level of explanation to which it is *assumed* every other level can be reduced. The point is not that we can know any particular theory of this sort to be TRUE, but only that we should rigorously pursue its consequences *as if it were*. My point then is that we should start by treating a theory of physical primitivism "as if true". If so, it is only consistent to suppose that any phenomenon under consideration in terms of that theory must be assumed to be adequately and fully accountable (at least in principle) at its lowest level of physical reduction. You persistently demur from this line of argument, but I think you miss my point, which is entirely harmless in every case except (I contend) that of the "1p part" of consciousness. It is entirely possible to understand a physically-instantiated computation (and hence, on CTM, an associated state of consciousness) to be the same physical process regardless of the "level of reduction" at which it is considered. After all, any such "level" is, in the end, merely a term of art associated with the theory in question. But what I'm questioning is whether it is coherent to (tacitly) treat the 1p part as merely such a term of art. My sense is that you equivocate on this, because if we only consider the 3p part (as in your analogy of the Mars Rover) the point (i.e. 3p-reducibility) is indeed harmless. But the 1p part resists 1p-reduction. It stubbornly is what it is. Hence my question essentially is about the kind of theory required to make sense of associating an irreducible 1p part with a reducible 3p part. AFAICS such a question cannot even be posed coherently in terms of physical primitivism. Indeed you have suggested that it is unreasonable to ask for this. What inclines me to Bruno's ideas (assuming CTM of course) is that this particular question may be better posed in terms of a theory that takes computation, not physics, as its primitive. I think the remainder of your remarks equivocate on precisely this 3p-1p distinction, so I won't comment on them specifically. If I've read you wrongly on this I'd be grateful for clarification. David On 8/22/2014 6:46 PM, David Nyman wrote: > > I must confess that I've been reading the MGA revisited thread with a > certain sense of frustration (notwithstanding that Russell has made a > pretty good fist of clarifying some key points). My frustration is that I > have never been able to see why we need an elaborate reductio like the MGA > to dispose decisively of a *computational* theory of mind on the basis of a > primitive materiality. The crux of the argument is whether the > "computational" part of the theory can be reduced without ambiguity to the > action of a physical device (e.g. a computer or a brain). If not, what > we're left with looks like a crypto-materialist theory in computationalist > disguise. In point of fact I agree with Stathis that multiple realisability > is already sufficient to establish this point. But let me elaborate a > little further. When we consider the matter, we don't actually observed > "computation" (in any rigorous mathematical sense) in physical reality. > What we observe in practice are physical devices of various kinds (indeed, > in principle, indefinitely many kinds) that we accept FAPP as adequately > instantiating particular classes of computation within certain fairly > stringent limits. > > > What we observe, aside from observing our own thoughts and maybe even > then, is always theory laden. Partly we see the world through a theory of > objects that evolution has provided us, sort of naive physics, but a theory > nonetheless as optical illusions demonstrate. > > > To put it another way, we are prepared to interpret the normal physical > behaviour of such devices *as if* it instantiated the mathematical notion > of computation. > > > Right, because it usually (modulo a dropped bit or so) does. > > > But at all times it is sufficient to assume that such behaviour, be it > of computers or brains, is constrained exclusively and exhaustively by > physical law. It's their net action, as physical devices, that is at all > times assumed to be essential, whatever "computational" (or other) > interpretation may be ascribed to them externally. Unfortunately, these > otherwise rather obvious facts tend to be obscured in ordinary, and even in > technical, discourse by the free intermixing of software and hardware > paradigms. > > These considerations should make it clear that any description of the > normal behaviour of a physical device as computation can only be in a sense > that is, ultimately, metaphorical. > > > I think you are too hung up on ontology. You denigrate everything that's > not in terms of the ur-stuff of (some unknown) true ontology as metaphor or > fiction. Why not accept that knowledge, including knowledge of ontology, > is always provisional and uncertain and it's best to think of it as a model > summarizing our best idea - but not necessarily the one TRUE idea. > > > This extends to any software re-description of physical action, as for > example Brent's Mars Rover analogy, or Dennett's "third-person absolutist" > take on perception and cognition. On the assumption of a "primitive > physical reality", such descriptions can (and indeed must) be understood as > metaphorical and approximate, not literal and "absolute". > > > Suppose the "physical reality" isn't primitive. So what? Molecules > aren't primitive, even atoms aren't primitive. But we can still describe > life in terms of certain processes at the molecular level. > > > They are grounded in the assumption of their ultimate reducibility, and > approximate equivalence, to some kind of net physical action. In this > light, physical devices don't literally "compute"; the most we need to say > is that their physical behaviour adequately *approximates* computation, > under suitable interpretation and within certain limits. Under such > constraints, it would seem that a so-called "computational" theory of mind > could in fact amount to nothing other than the claim that consciousness is > a *state of matter*. This particular state of matter, it would be claimed, > must obtain whenever physical action happens to be approximately > re-describable (at some arbitrary level) in terms of a certain class of > computation. > > > I'd say that pretty much the standard physical account of consciousness. > > > But given that the theory is grounded, and is at all times expressible, > in terms of an explicitly physical, as distinct from mathematical, > ontology, it is hard to discern how such a "computational" stipulation > could contribute anything intelligible to the claim. > > > It adds a great deal of intelligiblity, just as explaining how organic > molecules manage to perform metabolism, growth, and reproduction and to > evolve as part of living entities. There's lots of stuff we can't > understand at the level of 10^32 atoms but which we easily grasp at the > level of a table and chair. That doesn't mean we've invoked some magic. > > > > ISTM that the foregoing considerations are sufficient, on their own > merits, to establish the necessity of the reversal at Step 8, if a > *computational* (as distinct from some sort of tacitly crypto-material) > theory of consciousness, is to be salvaged. > > > ISTM that's like saying I'm not going to consider CTM unless it can saved > from being merely useful and/or approximate and shown to be absolute. > > > If so, it is indeed clear that the task becomes at least twice as hard > as before, as the observed correlations between matter and consciousness > now have to be justified on the basis of an ontology that is > (mathematically) adequate for a general and rigorous (as distinct from > local and approximate) emulation of computation. > > > I don't think it's any harder than the problem that Bruno created in the > first place by taking computation as basic. That means that mind AND > matter have to be explained as computation. It may make the mind part a > little easier, but I think it leaves the matter part pretty hard. > > Brent > > -- > You received this message because you are subscribed to the Google Groups > "Everything List" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to everything-list+unsubscr...@googlegroups.com. > To post to this group, send email to everything-list@googlegroups.com. > Visit this group at http://groups.google.com/group/everything-list. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
