I am not a big fan of Ludwig Wittgenstein. But I have to admit that he had a couple of good points. One was that a lot of philosophical problems (he said all, he was mistaken there) are a matter of unclear or ambiguous language. If we write clearly (which he certainly didn’t!), then we can “show the fly the way out of the fly-bottle,” that is, dissolve, rather than solve, such problems (Philosophical Investigations, 309).

One of my favorite examples of artificially constructed fly-bottle comes from philosophy of mind, in the form of the so-called “hard problem” of consciousness. The problem was invented by David Chalmers, who has since made a career out of it. (Before you ask, no I don’t think for a moment that Chalmers is in bad faith. I just think he’s mistaken.)

Essentially, the hard problem consists of the question of how to explain “qualia,” that is, phenomenal experience. Or, to paraphrase Thomas Nagel: what is it like to be you? Here is how Chalmers himself puts it in his “Facing Up to the Problem of Consciousness” from 1995:

“It is undeniable that some organisms are subjects of experience. But the question of how it is that these systems are subjects of experience is perplexing. Why is it that when our cognitive systems engage in visual and auditory information-processing, we have visual or auditory experience: the quality of deep blue, the sensation of middle C? How can we explain why there is something it is like to entertain a mental image, or to experience an emotion? It is widely agreed that experience arises from a physical basis, but we have no good explanation of why and how it so arises. Why should physical processing give rise to a rich inner life at all? It seems objectively unreasonable that it should, and yet it does.”

No, it doesn’t seem “objectively” unreasonable at all. It depends on one’s own metaphysical assumptions (more on this later). Now, if there is a hard problem of consciousness, surely there are “easy” problems. Sure enough, Chalmers gives us a list:

The ability to discriminate, categorize, and react to environmental stimuli;

The integration of information by a cognitive system;

The reportability of mental states;

The ability of a (brain) system to access its own internal states;

The focus of attention;

The deliberate control of behavior;

The difference between wakefulness and sleep.

I have suggested elsewhere that the problem Chalmers is so concerned with is based on a category mistake, and that it dissolves into a number of sub-problems, all of which he refers to as “easy.” Once (if, really, since there is no guarantee in science!) neuroscience and evolutionary biology will have answered the easy problems of consciousness, there won’t be a hard problem left, above and beyond the easy ones.

The term “category mistake” was introduced by Gilbert Ryle in his The Concept of Mind, published in 1949. It is a type of ontological mistake, as in the following scenario, articulated by Ryle: consider someone who is visiting Oxford University. The visitor, after viewing the various colleges, the library, the administration buildings, the faculty, the students, and so forth, asks: “Right, but where is the University?” The visitor is making the mistake of presuming that a University is part of the category “units of physical infrastructure” rather than that of an “institution.” His question may seem legitimate, and even sound profound, but it is based on a misunderstanding of what universities are. Similarly, understanding consciousness means to understand the “easy” problems, which means that once/if those will be solved, there won’t be any hard problem left.

You may have noticed that Chalmers asks two conceptually distinct questions, which will be answered (again, if at all) by two distinct fields of science: first, why does consciousness exist? Presumably, because it is advantageous for the organisms that possess it, like any other biological structure or property. So the answer to that question will come from evolutionary biology, probably along the lines of “organisms capable of conscious experience are better able to navigate their environment, thus increasing their survival and reproduction.”

Second, Chalmers asks how consciousness works. There the answer will come from neuroscience (and developmental biology). Indeed, we already have a good number of partial answers, relating to the neural bases of several aspects of conscious behaviors. We know quite a bit about the neurobiology of conscious and unconscious states, as well as of perception. We also know about a number of neurological disorders affecting consciousness, which provide us with precious clues about the phenomenon itself. Do we have a complete solution to the problem? Not even close. But that’s true in a number of other scientific fields (origin of life, fundamental physics, just to mention two), so that’s no argument to decree the problem of consciousness unsolvable by science.

Sometimes Chalmers & co. seem to be asking an altogether different question, which is — so far as I can tell — equally problematic. For instance, Frank Jackson has proposed a thought experiment concerning an hypothetical neuroscientist named Mary. Here is how it goes, from Jackson’s “Epiphenomenal Qualia,” published in 1982 in Philosophical Quarterly (volume 32, pp. 127–136):

“Mary is a brilliant scientist who is, for whatever reason, forced to investigate the world from a black and white room via a black and white television monitor. She specializes in the neurophysiology of vision and acquires, let us suppose, all the physical information there is to obtain about what goes on when we see ripe tomatoes, or the sky, and use terms like ‘red,” ‘blue,” and so on. She discovers, for example, just which wavelength combinations from the sky stimulate the retina, and exactly how this produces via the central nervous system the contraction of the vocal cords and expulsion of air from the lungs that results in the uttering of the sentence ‘The sky is blue.’ … What will happen when Mary is released from her black and white room or is given a color television monitor? Will she learn anything or not?”

This is baffling. The problem lies in the ambiguity of the last question: what does Jackson mean by “learning anything”? Mary will, obviously, have a new experience, one she had not had before. So, if experiences count as learning, the answer is a (trivial) yes. If, however, we are asking whether she is going to learn something scientifically valuable about the mechanisms of color perception by seeing color for the first time the answer (also trivially) is no.

Let me use an analogy to make the point even more clear. Suppose you study everything there is to know about the physics of bicycles and of their interaction with human riders. But you have, somehow, never actually ridden one of those contraptions. The first time you do, are you going to “learn anything”? Yes (you are going to have a new experience), and no (you aren’t going to acquire additional knowledge about the physics of bicycle riding).

Not content of having created a problem that doesn’t exist, Chalmers & co. have been proposing a number of “solutions” to it. One that has recently gotten a lot of attention is panpsychism, the notion that consciousness is “elemental,” that is, a basic property of matter. Panpsychism comes in a variety of flavors, but I’m going by the way the notion has been articulated by one of the leading supporters of the idea, Philip Goff. (If you are interested, I’m having an ongoing online debate on the issue with Goff.)

Basically, Goff and Chalmers argue that there are two broad ways to solve the hard problem: either one goes dualist, i.e., assumes that there are, somehow, things or phenomena in the universe that do not have a material basis, or one has to bite the panpsychism bullet, which “solves” the problem by assuming that consciousness is basic, and therefore doesn’t emerge in specific times and places during the evolution of the universe.

Dualism comes in two forms: substance and property. Substance dualism has been out of fashion since the time of Descartes, who was the last champion of the idea that there are two different kinds of substance in the world: matter and mind (famously, and entirely arbitrarily, he suggested that the point of interaction between the two substances is the pineal gland of the human brain). Property dualism is the notion that there is only matter, but that it somehow acquires certain properties (consciousness) when it is arranged in a certain way.

Now, if you simply put it the way I just did, I would find the notion entirely unproblematic, though I wouldn’t call it dualism. All sorts of new physical properties “emerge” when matter is organized one way or another. For instance, the wetness of water does not exist at the level of individual molecules of H2O. It emerges only when there is a large number of such molecules, and when they interact with each other within certain ranges of pressure and temperature.

What makes property dualism a kind of dualism is the further stipulation that consciousness is ontologically irreducible to neurobiology and physics. But why? If we simply stipulate this, we are engaging in a massive instance of begging the question. If, instead, we are invoking irreducibility just on the ground that science hasn’t arrived at it yet, then we are making an argument from ignorance. Either way, things don’t look good for dualism.

(I also wrote about yet another famous thought experiment proposed by Chalmers, arguing for dualism: the so-called philosophical zombies. He says that it is conceivable that one could encounter what looks and acts like a human being, including having a human-like brain structure and the capacity for language, and yet that this being would not have conscious experiences. The problem is that conceivability establishes nothing. For a long time it was conceivable that one could square the circle. It turns out that this is mathematically impossible. Just as it is physically impossible, in the universe in which we live, to have a living organism that is identical in structure to another and that nevertheless lacks some of the latter’s properties.)

Back to panpsychism. Physicist Sabine Hossenfelder has written an essay explaining why the notion that consciousness is elemental is incompatible with fundamental physics. Here is how she summarized the core of her argument:

“If you want a particle to be conscious, your minimum expectation should be that the particle can change. It’s hard to have an inner life with only one thought. But if electrons could have thoughts, we’d long have seen this in particle collisions because it would change the number of particles produced in collisions. In other words, electrons aren’t conscious, and neither are any other particles. It’s incompatible with data.”

I posed the problem to Philip, and here is his reply (from his second letter to me):

“I think Hossenfelder misunderstands the view she’s attacking. When one first hears about panpsychism, one thinks it’s the view that in addition to its physical properties — mass, charge, spin — a particle also has non-physical consciousness properties. That kind of panpsychism would lead to the kind of problems Hossenfelder points to, because we’d want to know what the consciousness properties of particles are doing over and above their physical properties. But Russellian panpsychism is very different: the view is that mass, charge and spin are forms of consciousness. If that makes sense (which we’re currently assuming), i.e. if micro-level forms of consciousness are identical with the properties invoked in the standard model, then clearly it’s mistaken to wonder what these forms of consciousness do over and above the properties of the standard model (because this implies that they’re distinct, when ex hypothesi they are identical).”

Goff is seriously mistaken here. First off, Hossenfelder is most definitely not assuming that consciousness is a non-physical property. If it were, she wouldn’t expect it to show up in physical experiments.

Second, I simply don’t know what it means to say that “mass, charge and spin are forms of consciousness.” Notice that Goff says that this is assumed ex hypothesi, that is, a priori. Problem is: this assumption is precisely what is under scrutiny, so one cannot take it as foundational. Are there any empirical reasons to think it holds? No, by definition. Are there any philosophical arguments to support it? Well, Philip continues:

“But how on earth could mass, charge and spin be identical with forms of consciousness? … You seem to suggest that the postulation of intrinsic natures is incoherent if particles are elementary. I’m happy to accept that quarks and electrons are fundamental, but we still need to ask about the nature of their properties. In my view, physics tells us what mass, charge and spin do (or more precisely the behavioral dispositions they endow to their bearers) but does not tell us what they are. Hence, it is coherent for the panpsychist to suppose that they are forms of consciousness.”

No, it isn’t. For a number of reasons. First, the panpsychist has to come up with a good argument for why there should be anything to say about electrons, quarks, etc. above and beyond their physical properties. The search for essences — which is what Goff is talking about — should have ended sometime during the Middle Ages, with the demise of the Scholastics. Second, even if we entertain the possibility that particles have essences, then we need to be told what such essences would look like, and how we could discover them. Last, but not least, the panpsychist would still have to come up with a positive reason for why the essence of particles is consciousness. Oh, and after all of that, we still wouldn’t know why human beings have first person experiences and rocks don’t. Or do they?

There is a very basic problem with what Chalmers, Goff, and others are trying to do: they are engaging in a type of metaphysics that used to be called “first philosophy,” to employ the term used by Aristotle. The last great work in this field was published in 1641 by René Descartes: “Meditations on First Philosophy, in which the existence of God and the immortality of the soul are demonstrated.” Descartes was alive right at the beginning of the scientific revolution. He was a contemporary of Galileo, and thought of himself as a natural philosopher, i.e., a scientist. Galileo too thought of himself as a (natural) philosopher. And there is a reason why today we look back at those two and label one a philosopher, the other a scientist.

That reason is that Descartes’ intellectual program has ran into the ground, while Galileo’s has taken flight. Science has replaced first philosophy, despite the fact that some philosophers have a hard time letting go. Does that mean that metaphysics is a thing of the past? Not at all. I’ve argued that philosophy, in part, make progress by simultaneously spinning off scientific disciplines (physics, chemistry, biology, psychology) while at the same time reinventing and repositioning itself with respect to those disciplines (philosophy of physics, of chemistry, of biology, of psychology).

The same is happening to metaphysics. While Chalmers is still practicing first philosophy, James Ladyman, Don Ross, and others are engaged in a program that they refer to as “scientific metaphysics.” This is the idea that metaphysics is not in the business of discovering new things about the world (science does that job now), but is rather tasked with making sense of the general picture that emerges from the sciences. Any individual science is not well suited for that task, because scientific research is highly specialized. To step back and see the whole, to appreciate how the disparate bits and pieces of information hang together, requires a different kind of approach, one that is best pursued by scientifically-minded metaphysicians.

The problem is that Goff not only is going back to first philosophy, he actually thinks that it can provide the underpinnings of a whole new science! His book is tellingly entitled Galileo’s Error. Foundations for a New Science of Consciousness. But Galileo did not make the error Philip is charging him with. And there is no such thing as a science based on statements that are entirely empirically untestable. The error isn’t Galileo’s, is that of some modern philosophers who insist in creating problems that don’t exist, and then spend a lot of time “solving” them in a way that rolls human understanding back four centuries.

Perhaps another piece of advice from Wittgenstein comes handy here: “Whereof one cannot speak, thereof one must be silent.” (Tractatus, 7)