Hi all,

It is very hard for me to tell on this list what is being sent me privately and what is coming over the list. I am trying to respond in the mode I received. Sorry for any mistake. Norman and John, I believe, responded on list, so here goes.

Norman, you say:

Also, I'm unable to find a meaningful (to me) argument against
reductionism.  Why is it in trouble?  It seems to me that even a complex
human being can be defined in concept by discrete quantum states and
particles, atoms and electrical charges.  "Thoughts" are therefore NOT
infinite because they can be conceptually defined in terms of particles and
quantum states, and there are not an infinite number of these permutations.

Okay, well here you have just asserted that human beings can be defined as the sum of discrete quantum states and the like and that thoughts are therefore not infinite.

If what you suggest is true, then your conclusion would follow. I claimed, though, that the reductionist thesis is in trouble, and you asked why. There is a huge literature on emergentism and reductionism, but let me just stick with the so-called mind-body issue that Hal also alluded to.

There have been two main reductionist strategies to deal with mental states, and they both -- to say the least -- have stalled. The two strategies are:

1.  Eliminative materialism
2.  Identity theory

Eliminative materialism argued that human behavior could be explained scientifically without reference to the mental states of folk psychology. S-R behaviorism -- as in Skinner -- was the great effort here, and it is now largely judged a failure. We seem to need mental states to explain human -- and even lower animal -- behavior.

So then there is the identity theory, the attempt to show that each mental state is identical to some (or finitely many) physical states. Well, this has not panned out either. At worst, we may be in for some many-to-many correspondence between mental states and physical states, which spells doom for identity theory and reductionism.

I probably have not said enough to convince anyone here. This is a big issue, and much more could be said. I am just trying to summarize the current status of the mind-body debate. At the very least, the reductionist argument has been stalemated -- and there are good reasons, having to do with the role of language, for thinking it is false.

Norman suggests the upshot for the Tegmark thesis:

"Thoughts" are therefore NOT
infinite because they can be conceptually defined in terms of particles and
quantum states, and there are not an infinite number of these permutations.

Well, only if reductionism succeeds. If reductionism fails, then, unlike universes, which, on my reading of Tegmark, are discrete and countable, thoughts are not only infinite but uncountably infinite. In that case, thoughts -- and persons -- comprise an even larger infinity than universes. And -- although this is another argument -- at least a part of the universe would not behave deterministically.

If you tend to resist what I am suggesting, consider three things:

1. How do you even individuate thoughts so as to count them or correlate them with physical states? Is the belief that Mark Twain wrote Huckleberry Finn the same as or different from the belief that Samuel Clemens wrote Huckleberry Finn? Would that be one physical state you would seek to correlate with it or two? There are lots of well-discussed conceptual problems here.

2. The mind-brain relation has sometimes been compared to the relation between software and hardware in computers. A certain software function might be endlessly realizable by different physical (hardware) configurations in different computers. Similarly, I suppose, the same hardware configuration might realize different software functions in different computers. The analogy might break down, but this is the idea.

3. The denial of reductionism does not necessarily entail belief in what is called "a ghost in the machine," i.e., a soul or other mystical something. The denial of reductionism may instead imply that not only is there no ghost, there also is no machine (i.e., we don't behave in machine-like ways). (This is a point made by Searle.)

John, I am not sure I understand everything you said. One thing I would say along lines I think you suggest: Determinism suggests a closed system. If you don't have a closed system, you don't get deterministic predictiveness. Human thought is both holistic and unclosable. Those features do not preclude mental causality, but they do preclude deterministic, causal laws.

Well, I hope I have not bored you all, but I do think that there are considerations from the social sciences that bear on -- and possibly challenge -- Tegmark's thesis.

Thanks for your responses.

doug porpora
dept of culture and communication
drexel university
phila pa 19104


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