For some time now, I’ve been discussing materialism on John Wright’s blog; the discussion is spread over several posts, of which I link only the most recent:
Now Mr Wright has written a good summary of the respective positions; it seems I won’t have to write my own summary post, which is just as well given everything else I need to do this week. I will make my first response here, and see where the discussion develops. In particular, I take issue with this:
Somewhere [if materialism is true] there is a set of atoms in a certain configuration that makes it the case that materialism is true. Could in theory a workingman [referred to later as the Demiurge] move one group of atoms from the positive to the negative so that it was no longer the case that materialism was true?
I do not think this is a valid phrasing of the materialist position. It appears to confuse the representation of the statement in human brains, with the actual state of the universe, or some similar category error. “Materialism is true” has as its referent the entire universe; it is the statement that once you have written down the global wave function, there is no other information, and no additional fact which needs explaining. (Which does mean that the materialist position has the difficulty of proving a negative. The non-materialist only needs to be lucky once: a single finding which the materialist cannot explain in terms of the quantum wave function would invalidate the materialist position. Before anyone points out that it’s impossible to prove a negative, yes, I know; it is however quite common to have evidence such that the negative is the most likely possibility.) There exist atoms which encode this information in human brains, and indeed there exist atoms which encode its negation (although those brains are mistaken), but there does not exist a subset of atoms which makes the statement true; rather the statement is true because nothing but atoms exists.
To answer the question about the demiurge, then: If he is to be taken as existing within the universe, then he cannot change materialism’s truth value; whatever he does to other atoms is either explainable, or not, in terms of the Dirac equation. If, on the other hand, he is not part of the quantum wave function, then his very existence is the additional fact which destroys materialism.
However, I find an additional question occurring to me. Suppose we find such a Demiurge, a being or force not explainable in terms of quantum mechanics. It may still be the case that this being acts according to laws which we can discover; and in such a case, could we not simply extend our defition of ‘materialism’ to say instead “The statement that everything can be explained in terms of either the global wave-function, or the laws which govern the Demiurge”? I feel that this is cheating and that the materialist ought instead, in such a case, to throw up his hands and admit error. But it is not immediately obvious to me what the cheating consists of.
Let me therefore try to rephrase the materialist position so that it cannot be cheated on in the manner above: Materialism is the position that there is only one level of explanation; that concepts such as ‘mind’ are not ontologically fundamental. Materialism holds that all apparently complex processes can be reduced to simple ones, even if the reduction is computationally nontrivial. Thus, if I found a Demiurge, and I found that its mind exhibited, say, an analogue of human anger, and I could not reduce this top-level concept to smaller pieces, then materialism would be invalidated even if there were a high-level law regulating when the anger-analogue appeared. If, on the other hand, I found that the Demiurge’s anger was reducible to, let’s say, the density of angrons, whose behaviour followed the Andreassen Equation, and I managed to produce angrons (and their antiparticles, happons) in a particle accelerator, and I could spray them at my enemies or display them at birthday parties – then I would merely have found a previously unknown bit of materialism. Given this restatement, then, perhaps reductionism is a better word than materialism.
This does raise the question of what is a high-level concept and what isn’t; just how complex does an irreducible phenomenon have to be, before I’ll call it non-materialistic? I don’t have an immediate answer, although clearly the Dirac equation is a lower bound; and if I found that human emotions were irreducible, I would call that non-materialistic. But for complexities in between, I’m not sure where I would draw the line.