Joel wrote: >What is the mind-body problem?
The formulations are as numerous than the philosophical systems. For a materialist the problem is to explain what are the necessary and sufficient conditions for having the feeling of pain in a leg. For an idealist the problem is to explain what are the necessary and sufficient conditions for having the feeling that there exists things like electrons, waves, chairs, and neurons... For an dualist the problem is to explain the relationship between mind and matter. (cf Descartes "modern" formulation). In general the mind body problem is tackle by religion. Some "scientist" does not believe there is a mind body problem because they are unaware that they believed in the "matter religion". The mind body admit a lot of subproblem, like what is free-will, is there an afterdeath, what is the nature of qualia, etc. >What does "first person" and "third person" mean? I know from your post that you are computationalist, i.e. you can imagine that our consciousness is can be retrieved from the working of a pure finite computation (by a universal minimal cellular automaton for instance). Then you agree that in principle you are duplicable (at some level of description). Suppose you take on you a intime diary where you note the result of your "personal" experience. Now I make here (at Brussels) a copy of your actual description, then I annihilate you, and then I make you reconstituted at both Washington and Moscow. A first approximation of the "first person" is given by the content of your diary. Because you keep your diary with you, it will be duplicated too. It will contain either "I wake up in Moscow, what a nice city, etc.", or "I wake up in Washington, what a nice city, etc.". A third person description is a verifiable one by an external (not duplicated) observer. It can contain something like "Joel wakes up successfully in both Washington and Moscow. It has been confirmed by two phonecalls, etc." This gives a striking illustration of the difference between the two discourses. What is an "and" (Moscow "and" Washington) in the 3-description becomes an "or" (I wake up in Moscow or in Washington) in the 1-description. It is easy (for some at least!) to realise that (with comp) we cannot predict the "result of experience" for self-multiplication experiments. This indeterminacy can be shown not depending of the contingent feature of the reconstitutions. Look at the UDA for a description of the consequences of that proposition. It entails a priori explosive sets of possible 1-continuations. There is a kind of complementarity/duality between 1-3 description versus discrete/continuum. If we can be "captured" by a finite discrete code, then we cannot avoid some confrontation with the continuum under one form or another. Sometimes I summarise that view on the foundation of math by paraphrasing Kronecker : God creates the Natural Numbers, all the rest are ... dreams by Natural Numbers". (Kronecker says "... all the rest are human inventions; I generalise Kronecker by replacing human by universal turing machines). Now, with comp dreams obeys the laws of dreams (the laws of the consistent computational extensions), and the appearance of the physical must be explained by the logical structures of those sheaves of dreams. If your cellular automata generates everythings it will do it in an extraordinary terrible redundant way. The computational indeterminacy must be quantified on the set of *all* consistent continuations. Bruno http://iridia.ulb.ac.be/~marchal
