Physicalisms

Physicalisms

The word “physicalism” covers a multitude of sins: it is vague, honorific, and deeply mysterious. What does it mean? Don’t say it means “what physicists do”—that is completely circular and uninformative. Also, physics varies from one physicist to another: whose physics do we mean? Do we mean Descartes’ physics, centering around the notions of extension and mechanism? If so, empty space is physical. Do we mean Locke’s physics, in which solidity is the key idea? Do we mean Newton’s physics, in which we have the ideas of mass, force, and acceleration (plus gravity)? Is motion the essence of the physical (matter)? Do we mean Clerk-Maxwell’s electro-magnetic physics with its fields and ethereal forces? Do we mean Einstein’s physics and its apparatus of frames of reference, speed of light, denial of absolute simultaneity, time dilation, and curved space-time? This is a good deal conceptually richer than earlier conceptions of the physical. Do we mean quantum-mechanical physics with its weird and wonderful ontology and dynamics: indeterminism, wave-particle duality, entanglement, wave-function collapse, particle dissolution? Or do we mean an energy-based physics in which solid located bits of matter are a thing of the past? Or do we go the whole hog and opt for an Eddington-style physics in which the essence of matter is consciousness (or some such), or Russellian neutral monism? Don’t say we should plump for what is in common to these various theories, because that will require us to fall back on the idea of “the physical”, for which we have no definition; and there is nothing in common between them at the level of basic theoretical concepts—they are rivals. We can’t even unify gravitation theory with quantum theory. It’s really a hotch-potch of ideas designed with different goals in mind than explaining the mind.

It won’t help to move up a level and try to define the physical in terms of the organic body, say by reference to behavior or the brain. Do we mean the behavior of Pavlov, Watson, Thorndike, or Skinner—and what is meant by “behavior”? Not inner behavior, to be sure, so we must mean physical behavior—whatever that is. And do we include volition in our concept of behavior? In addition, we don’t get reduction of the mental to the physical if behavior is not reducible to the physical, so we are still stuck with explaining “physical”. Nor is the brain any help: what theory of the brain—vitalist or mechanist, localized or holistic? What properties of the brain are allowed—informational, panpsychist, unknown? No, we need to include only the physical brain if physicalism is to be vindicated, but we have yet to define the physical. Do we mean some hypothetical future physics quite unlike our present physics? But that leaves us with no conception at all, and is consistent with a future physics that denies all of current physics. The only concrete meaning is given by specific theories, but there are many of them—so many physicalisms. We might hope to make progress by narrowing it down to some concept agreed upon by all theories—say, shape or motion. Assuming these notions are not too elastic, we at least have a well-defined theory of “physicalism”—which we may label “shapism” and “motionism”. Thus, the mind is reducible to shape or to motion or possibly to both. But who holds that view? It sounds grossly implausible without the magic of that nebulous word “physical”. What shape is pain or thought or emotion—triangular, oblong, star-shaped? And is the mind an arena of motion—thoughts and feelings zipping around like so many weightless projectiles? What speed are they going, do they ever stop moving, how much slower than the speed of light are they? Is quick thinking the same phenomenon as a ball flying through space (the width of a skull)? So, the more specific and concrete we get in trying to find a formulation of physicalism, the more balderdash we spout. There is simply no content to the idea, or a ludicrous content. No one ever claims that mind (consciousness etc.) is the same thing as shape, solidity, motion, force, acceleration, electro-magnetism, curved space, quantum jumps, muscle contractions, salivation, pecking, etc. People just have a hazy (uninformed) idea in their mind of some recondite physical stuff that the mind might reduce to, because actual physics contains nothing even remotely plausible. And if mind were really matter, wouldn’t any property of matter have the seeds of mind contained in it—mass, shape, texture, sharpness? Paradigms of the material are hardly paradigms of the mental. If mind were matter, matter would be mental in its most basic form. Hence all the shady talk of emergence and supervenience. Were early theories of matter, as pronounced by the pre-Socratics, already decent stabs at the nature of mind? If some ancient Greek had stated that mind is mud, would we say “Good try old chap, but in need of a little refinement”? Or mind is sand, or mind is pebbles, or mind is sea water (matter being fresh water). Are modern theories of matter really any better from the point of view of explaining mind? What have Newton’s three laws of motion got to do with thought and feeling? Physics proper, as opposed to some fanciful idea of it, has nothing to do with mind; its basic concepts contain no hint of the mental. You might as well be a “botanicalist” about the mind—the mind consists of peas and cabbage.[1]

[1] Physicalism today is really no more plausible as a theory of mind than physicalism of the seventeenth century; it isn’t as if the progress of physics has made it any more explanatory of the mental than it used to be. We haven’t moved the physical world closer to the mind than it seemed in the past. One would think, if physicalism were true, that the progress of physics would have revealed the physical basis of the mind, but nothing like this has happened. The physical is no closer to the mind that it was three hundred years ago (or two thousand years ago). All we have are loose correlations not explanatory connections.