David Nyman wrote: > 2009/9/24 Flammarion <peterdjo...@yahoo.com>: > >>> if it can't, we need another strategy to >>> disambiguate its actual relation to the physical account. The latter >>> conclusion is what motivates the reversal of matter and mathematics in >>> comp. >> There is no ambiguity in the reduction of computation >> to physics. > > How long can you go on arguing what is not disputed? Keep clearly in > mind the third-person, first-person distinction. There is no > ambiguity in the physical reduction of any realisation from a > third-person perspective. From this perspective, the homogeneity of > state that supervenes on the physical heterogeneity is merely one of > interpretation - i.e. it is an abstraction and immaterial to the > physical account. The problem is in introducing a mental type that > equates to the computational one; now you have an actual homogeneity > of experience to explain, not merely a metaphor. > > But there is no way to explain it on the basis of any consistent > physical low-level account of a mental type; only a different one for > each occasion of realisation.
That's where I think you're asking for the impossible. An account of perception obviously cannot be "low-level", it must be in the context of perceiving something. I don't think cogitation is qualitatively different, it is, as Hume said, just less distinct and vivid. So there can be no low-level explanation of cogitation either. There can be a low-level physics explanation of the physical process of a person playing chess - but to explain it *as playing chess* requires a context in which "chess" is meaningful. > We're not only talking about small > differences between brains, we're talking about any arbitrary level of > physical heterogeneity that falls within the type. This is an > ineluctable consequence of MR. But it is unrelated to the process of > consistent hierarchical reduction that is central to physical > explanation. The physical heterogeneity can only extend as far as the boundary beyond which there is a context which allows the process to be defined as a computation or a thought. An artificial brain in a human body can have human like experiences because it functions within our world. If it is functionally detached from our world, i.e. has no causal history linking it to events in our world, then it will be no more conscious than a rock in our world. This is hard to think about because in the case of the artificial brain, unlike the rock, there are intermediate degrees of relation to our world, e.g. it interacts with a tape of our world. I know you will say this is 3rd-person. But as I understand the terms, I think it is impossible to *give* a 1st-person account since a 1st-person would have to be something you experience. > > This leaves CTM entirely devoid of any physical basis for attaching a > homogeneous first-person experience to heterogeneous physical > processes other than its own brute general posit; and circularity can > count as explanation in nobody's book. But a "brute posit" can count as explanation if it turns out to correctly predict something we didn't know. When Newton was asked what transmitted the gravitational force between bodies, he replied, "Hypothesi non fingo." Brent >This point is never argued in > detail by supporters of CTM - rather anyone who points it out is > denounced as unenlightened and unworthy of a reply in kind. Certainly > they don't get one. > > Whether this motivates abandoning PM rather than CTM depends on how > strongly one is committed to PM. If the fishy smell left by the > shoulder-shrug that passes for physical justification in CTM > nonetheless leaves one with a residual appetite for computationalism > as an explanation for mind, then the switch in metaphysical posit may > be preferable, at least as a working hypothesis. > > David > > > > > --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
