I am sorry that I have not been able to keep up with the list lately. I can only peek in occasionally.
My interpretation of the question of computationalism vs supervenience can be put succinctly. Computationalism says that consciousness depends both on actual behavior and on counterfactuals. Therefore, it depends both on what happens and on what doesn't happen. Supervenience says that consciousness depends only on physical behavior; hence it depends only on what happens. Since computationalism says that consciousness depends on what doesn't happen, while supervenience says that it depends only on what happens, the two doctrines are inconsistent. To marry them would require altering computationalism so that it no longer depended on counterfactuals, which then requires us to say that all systems implement all calculations. As far as this latter question, the framework I adopted and adapted from Wei Dai, which I call UD+ASSA, suggests that there is a sense in which it is true, but it is not significant or meaningful. The UDASSA framework seeks to calculate the measure of a conscious experience. We start by thinking of a conscious experience as something that can be described as an abstract information pattern. Any physical system which instantiates that information pattern can be said to contribute to the measure of that conscious experience. The Universal Distribution defines the measure of an information pattern as the fraction of all programs that output that pattern. Equivalently, the measure is the sum of 1/2^L_n, where L_n is the length in bits of the nth program that outputs the pattern. Short programs have higher measure than long ones; hence to a good approximation the measure depends on the length of the shortest program that outputs it. If we consider all programs, some of them instantiate or simulate "physical" universes. They have their own laws of physics and initial conditions. Some are complex, some simple. In those universes we may find physical systems which we would naively view as instantiating particular computations, even conscious computations. We would like to say that such universes add to the measure of those computations. In the UDASSA framework, this is handled by imagining a two part program. The first part creates and runs the universe; the second part scans the output of the first part and outputs the abstract information pattern that represents the conscious experience. The size of this two part program is the sum of the size of its parts. Only if both parts are small will the contribution to the measure of the experience be large. As has been discussed here, in principle you can find a mapping from any physical system to any computation. This threatens to lead to the conclusion that every consciousness is instantiated by every physical system. Traditionally, computationalism opposed that conclusion by insisting on support for counterfactuals. But the UDASSA framework handles it in a different way. In the UDASSA framework, a mapping from, say, a solid rock to an abstract information pattern representing a moment of human consciousness would be a very large program. In truth, this mapping program wouldn't even need to use the rock. It could output the human information pattern just as easily without the help of information from the rock. The mapping program will need to include all of the information and programming needed to generate the human consciousness information pattern essentially from scratch. That's going to be a very large program. In contrast, a mapping program that goes from a human brain to an abstract information pattern representing a moment of human consciousness can be quite compact. It would use the physical information from the human brain state and translate that to whatever form was used to abstractly specify the computational state. While this might be modestly complex, it would be far, far simpler than the nearly-astronomical complexity needed to output a human brain experience from a rock. The result is that physical systems which have plausible "naive" interpretations as implementing certain computations will contribute significantly to the measure of such computations; while physical systems where we would need a contrived and complex mapping will contribute negligibly to such measure. This provides a reason, within this framework, to neglect the possible existence of conscious entities created by non-conscious computations. Any mapping which could specify such an entity will be enormous and will not contribute meaningfully to the measure of such entities. Hal Finney --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
