In my last post I argued that physicalism cannot be rejected simply because people assert there are nonphysical objects which are beyond specification. Some are, however, specifiable, and one commentator has identified the obvious ones: abstract objects like the rules of chess or numbers. I have dealt with these before in my “Pizza reductionism” post, which I invite you to go read.
Done? OK, then; let us proceed.
It is often asserted that there are obviously things that are not physical, such as ideas, numbers, concepts, etc., quite apart from qualia, I once sat with a distinguished philosopher, who I respect greatly and so shall not name, when he asserted that we can construct natural classifications because we can deal first with the natural numbers. I asked him “In what sense are numbers natural objects?”, meaning, why should we think numbers are entities in the natural world. He admitted that the question had not occurred to him (I doubt that – he is rather smart), but that it was simply an axiom of his philosophy. I do not think such abstract objects are natural.
This applies to anything that is “informational”, including all semantic entities like meanings, symbols, lexical objects, and so on. They only “exist” as functional modalities in our thoughts and language. I have also argued this before: information does not “exist”; it is a function of how we process signals. Mathematics is not a domain, it is a language, and the reason it works is because the bits that seriously do not work are not explored far[*] – not all of it has to work in a physical or natural sense, but much of it has to, or else it becomes a simple game that we would not play so much.
So the question of the incoherence of physicalism is based on the assumption (which runs contrary to physicalism, and is thus question begging) that abstract objects are natural things. I don’t believe they are, and I certainly do not think that a thought, or concept, for example, which can be had by many minds and is therefore supposed to be located in none of them (and thus transcendental), really is nonphysical. That is another case of nouning language. The thought “that is red” exists, for a physicalist, in all the heads that meet the functional social criteria for ascriptions of red. It exists nowhere else – it just is all those cognitive and social behaviours in biological heads.
I’m riding roughly over some fine grained philosophical issues here, I know; but we don’t need to resolve these yet. It’s enough to say that the abstraction objection (which deserves initial capitals: Abstraction Objection to Physicalism, or AOP, because philosophers love acronyms even though it impedes communication) simply fails on the face of it, and needs a whole lot more work to make a prima facie objection. But because we privilege the mental, linguistic and formal (as philosophers) over the physical, it appears to have some probative (i.e., evidentiary) force in the debate. But this has never to my mind been shown.
By the way, the view of abstract objects I prefer is that of Ed Zalta, who defines an abstract object as an object that is not located in space or time. If physicalism is true, abstract objects are only concrete objects without the location indices. And since everything has a location index under physicalism (even if vaguely), abstract objects are fictions we find useful. Much of the supposed counter instances to physicalism are useful fictions, like corporate personhood.
In the first post I dealt with the qualitative objection (sorry, Qualitative Objection), and now I have discussed the Abstraction Objection. Are there other objections to deal with? Our commentators have given us one, at least: the Purpose Objection. As Nagel (and Fodor) have argued, a naturalistic (that is, a physicalist) world view seems to have no place for irreducible purposes, and in a way that is true. The notion that purpose is a natural property of the universe is definitely not a physical notion. And yet, they say, living things have purposes, and without purpose there is no explanation of how the incredibly rare facets of life, and indeed life itself, could evolve.
But this is an asinine objection, again begging the question – since there is an assumption of purpose in the universe, the interlocutor has already rejected physicalism. Instead we should only ask if there is the appearance of this natural purpose, and there are satisfactory accounts of that. We might say that purposes are determined by functional success. But this is not the Nagel-Fodor objection as such. Instead they find the very existence of selection processes and their outcomes unlikely to the point of miracle. I can understand they find this unlikely. But their own incredulity about physical processes leading to functional life and selection processes is based upon ignorance, as it is for those of us who find life and its processes very likely given the right circumstances – we simply do not know enough to estimate the likelihoods. After the fact, if life arose naturally (that is, physically), then the likelihood is one. But if we presume the likelihood is low, then the existence of life is a problem.
Do you see the trick? Assume that some directive purpose is necessary and you will find the natural existence of life unlikely, which you can then use to deprecate natural accounts of life. Again, it depends upon privileging something human – in this case, intelligent purpose – in order to find processes that do not privilege the human somehow deficient. This, by the way, underpins (and the fallacy undercuts) the argument from design used by intelligent design advocates.
To summarise this already long post (sorry): if we assume that symbols are abstract then any statement of physics is a counter instance to physicalism; but if we are physicalists, then we do not assume that symbols are not physical. Physicalism is coherent, but you might need to revise some of your untested assumptions. And chance and necessity can deliver outcomes that we presume must be the result of design, since we are designing entities. Again, we beg our question.
One final point about design and directed purpose: the mere having of a purpose in no way guarantees that the outcomes will match it. As someone once noted, the lion intends to eat the gazelle and the gazelle intends not to be eaten, and yet the process that results is one of natural selection, which is an unsupervised process. If wishes were horses, beggars would ride. The old saws cut best…
* Yes, I know mathematicians explore areas like group theory and spin glass and so on that later turn out to have practical implications. This should not surprise you. For a start, mathematics explores the implications of mathematics that does work, and also we mark it when bits of mathematics have applications. As Francis Bacon so rightly said, “Men mark it when they hit, but do not mark it when they miss”. In other words, the practicality of mathematics and all other logical formalisms is a Texas Target.