The All-At-Onceness of Conscious Experience

Way back in the first chapter, we looked at the Hard Problem, which for people of a certain temperament is a bit radical in its implications. This is the idea that you can never account for the redness of red with a story about causal bonking alone, no matter how much you dress up the bonkings with fancy words like "refer", "algorithm", or "information". Trying to fix this problem by looking at the bonkings from a "high level", or collecting them into black boxes, as functionalism does, does not work either.

Given the reality of phenomenal consciousness, this is troubling beyond the problem of explaining consciousness, because it tells us that any framework for understanding reality (like physics, as currently construed) that consists, at bottom, of a story about causal bonkings is at best incomplete. The redness of red gives us a counter-example to the causal bonking story.

I hope by now that you accept all of this, and that you agree that the Hard Problem is a real problem. If so, you are in reasonably good company - lots of philosophers are troubled by the redness of red. The redness of red is just the tip of the iceberg, however. Some physicalists brush the Hard Problem aside as a mere intuition. Maybe it is, but for reasons I have already covered, it's an awfully compelling one. In this chapter, I ask you to accept what seems, as first, as an even kookier one, and one that is a bit more abstract, but one that I think is just as compelling. In fact, it is really just a logical extension of the original redness-of-red Hard Problem. If you accept one, you should accept the other. Same bullet, maybe another set of tooth marks.

As we encounter things in the world around us, when do we judge something to be just a heap or aggregate of smaller things, like a pile of sand, and when do we judge it to be a true, unified, single thing? It depends, almost always, on how you look at it. When we look at the world in strict reductionist terms, nothing above the sub-atomic level really counts as a holistic thing. Are there any things above the micro level that really are inherent, single things in a way that does not depend on how you look at them? Do we have any reason to believe that there are, in contrast to the reductionist view, inherently unitary mid-level things in the universe? Put another way, if some philosophical pedant says, "That's not a table, it's just a bunch of atomic matter arranged in a tablewise fashion", are there any things in the world (excepting the atomic components themselves) of which this is simply not true? Is there anything you could show the pedant and say, "No, that is just absolutely a table."? We do, in fact, have evidence of such things, and the evidence, as with the redness of red, is our own phenomenal consciousness.

I have an art nouveau poster in which a woman is smoking, and there is a stylized curl of smoke rising from her cigarette. When I look at that languid asymmetrical curve, I see the continuous curve in its entirety, all at once. I do not just have some kind of cognitive access to the fact of the curve. The parameters of the curve are not just available to me upon making certain kinds of inquiries. I do not just have a pointer or reference to a lot of data beyond my view that yields results pertaining to the curve when evaluated. The details of my perception are not just at my fingertips, but bam! right there, live, all at once. I see the whole curve now. This is every bit as undeniable as the redness of red. However you might nibble at the edges of my perceptual field, there is a wholeness to that curl of smoke that is manifest before me, in a qualitative way.

In contrast, of an intelligent computer with its video monitor aimed at the curve (LDA, STA, JMP…), all we can say is that at some level it may be thought of (by us) as seeing the curve. That is, given an abstract understanding of its algorithm and data structures, one may interpret the functioning of the machine as "seeing" the curve. This, however, is anthropomorphizing on our part, albeit on the basis of the computer's deliberately programmed design.

As with seeing red, any claims about what a computer could or could not perceive apply equally to my zombie twin. We have no principled way of saying that the zombie sees the curl of smoke, in spite of its ability to answer questions about it, report on it, or makes claims that it sees it. We are faced with the same failure of entailment, the same explanatory gap as we were with the zombie seeing red.

There is, in contrast, nothing "may be thought of" about my seeing the curve. It is not a matter of interpretation. It is an absolute fact of Nature that I really do see that curve all at once, before me. Seen at the low level, as an ant-like CPU crawling over data gravel, there is no inherent sense in which "it all comes together" for a computer, whereas there is an inherent sense in which it all comes together for me.

This is not just another "I see red, the computer will never see red" argument (although it is related). The "seeing red" arguments focus on qualitatively rich but nevertheless cognitively simple aspects of experience. I am talking instead about our ability to have cognitively complicated scenes before us in our mind's eye, to see the complex as one thing, all at once in its entirety: e pluribus unum. Assuming we take the Hard Problem seriously, as we think of the sorts of mental phenomena that compel us to do so, we often cite the good old redness of red, tickles, itches, pains, saltiness, etc. as paradigmatic qualia. But once we go that far, this wholeness-quale is just as troubling. It is just as much an essence as the taste of ice cream is in the Hard Problem sense.

I would like to distinguish this unity of conscious percepts from the so-called binding problem, however. The binding problem refers to the fact that, for example, the visual processing parts of the brain and the auditory processing parts are quite different, and in fact take different amounts of time to do their jobs. In spite of these facts, we can have a single experience that incorporates elements from several senses at the same time, and they are synchronized. The binding problem is fascinating in its own right, but what I am talking about here is, I think, at least as fundamental. I am concerned not so much with the way in which different sense modalities (vision, hearing, smell, etc.) can be bound together in a single percept, but how anything at all, even within a single sense modality, can have the kind of unity it does. This qualitative gestalt is every bit as strange and inexplicable as the redness of red. Even my fellow qualophiles do not pay enough attention to this.

It could be argued that my percept of a tree is not an indivisible whole: you can break it into parts (leaves, branches, trunk). But that only means that I have a tree percept, then, often by effort of willful analysis, I have a subsequent follow-on percept of tree parts, albeit possibly with tendrils of reference reaching back to the original unitary tree percept. Just because a cathedral is made of stones, it does not follow that my conception of a cathedral is made of my conception of stones. Even if my conception of the cathedral incorporates the knowledge of the stones, there is still a single experienced percept of the cathedral that subsumes this fact.

My percepts are immediately, manifestly unitary whole things. Regardless of the cognitive or physiological mechanism which supports them, they serve as a counter-example to the doctrine of ontological reductionism. I know I perceive my percepts, and that those percepts really are whole objects just as certainly as I know I see red. Things, in my mind, are qualia, as are all abstractions - manifestly before me, all at once. Out in the world, there may be only a bunch of atomic matter arranged in a tablewise fashion, but in my mind, if only in my mind, there is a table.

Consciousness gives us not only examples that there are such things as qualitative essences in the universe, but also that there are such things as things. This claim may strike some people as a case of comparing apples and oranges. "Just because you perceive something as an inherent whole doesn't mean it actually is an inherent whole", one might be tempted to argue. "You are just interpreting it that way." But it is the percept itself, the interpretation (if you must call it that), not the thing out there in the world that is being perceived, that I am talking about. "Your percept only seems like a unified whole" is analogous to the claim that "electromagnetic radiation at around 430 THz only seems red". It is that seems part that we have to explain. My claim here is that the seeming of unity must itself be a unity.

If these percepts are things in the deep, inherent sense that I claim, how many are there? What are their boundaries? Is that stylized curl of smoke really itself a thing, or part of the larger percept of the poster as a whole, or even some even bigger percept, one that is even connected by filaments of association to others, or memories, who knows what? I don't know (yet). There is more work to be done to answer these questions. The point here is that we only need a tiny bit of unity to break the reductionist's claim. Maybe I don't really see as much or as clearly beyond the center of my field of vision as I think I do, maybe I am susceptible to all kinds of illusions that demonstrate how hard it is to specify the edges of my percepts, but as long as I see any of that curl of smoke, we need to say how that could possibly be.

We must take first person experience seriously, both in the seeing red case and in the case of the unity of our percepts. Both (and perhaps more besides) must be explainable in any final theory of nature we concoct. Such a theory must include principles of individuation that allow for the mid-level things that are my percepts. Gregg Rosenberg discusses this quite a bit (although from a somewhat different perspective). To use his term, we need a theory of natural individuals.

So when I claim that these unities, however they are demarcated, are some kind of true, inherent, fundamental unities, am I talking about, well, physics? Yes I am. As with the redness of red, I think we need to go all the way down with this. Otherwise we are left with some kind of functional unity made of blind causal bonking, and that would not give us the qualitative sense of that curl of smoke as a curl, any more than it would the color of the poster's background.

There are inherent, absolute things above the level of the quark, but below the level of the whole universe itself. These mid-level things may only exist in our minds, but that is enough to say that they do exist. Like my seeing red, these things in my mind can not be illusory. If it seems that there are mid-level unitary things among my percepts, then those seemings themselves must be mid-level unitary things. For my unitary percepts to manifest themselves to me as they do, they can not just consist of smaller parts integrated only through causal dynamics, bits bonking blindly into other bits, with some sort of functional description emerging from the bonking, any more than the redness of red can. Whatever the crumbs are out of which the universe makes everything else, these things count among them, rather than things built out of the crumbs. They are just bigger crumbs than the kind we are used to.

I want to emphasize that when I say that my conscious perceptions are "mid-level" things, I am talking about the scale (between quark and universe), and definitely not implying that these things occupy some middle level of a tree of organization. In that sense, the whole point is that these are low-level things. They are big and complex, yet they must count as primitive objects. They can't be exhaustively characterized in terms of any lower level of description or analysis. There is certainly a huge number of possible conscious percepts - quite possibly infinite. All this being true, we live in a universe in which there is a huge (possibly infinite) number of fundamental components, these components have qualitative essences, and most of them are big and rich, not tiny and simple. Any formulation of reductionism that could accommodate these facts would hardly be worthy of the name.

In the last chapter, I characterized reductionism as consisting of these premises:

1. everything in the universe is made of simple building blocks
2. anything we choose to study may, in principle if not in practice, be defined and described completely in terms of the simpler building blocks of which it is made
3. there is a finite (and small at that) number of types of these basic building blocks
4. each instance of a particular building block is interchangeable with any other instance of that same building block (one electron is absolutely identical to another electron)
5. these building blocks are entirely characterized by their functional dispositions (i.e. they have no qualitative essence, just behavior, such as that described by the lowest-level equations of physics)

What I am saying in this chapter is that our percepts and thoughts, whatever else we may say about them, definitely violate #3, #4, and #5. We are left with a baroque universe, with a huge mess of primitive components, a lot of which are big.

It is worth noting, however, that this view is nevertheless reductionist in a sense. Everything in the universe may well be reducible in principle to its component parts - it is just that there is no small number of such fundamental components in the universe, and a lot of those fundamental components are pretty substantial things in their own right. The important respect in which it still counts as a form of reductionism is that under this view, you do not get anything out that isn't there in the lowest levels. Specifically, this view does not posit any magic "emerging" from a system on the basis of its "complexity" or functional organization. Complexity and functional organization, defined in causal terms, smeared out across time, and dependent on lots of hypotheticals, doesn't confer the kind of inherent, just-is, really-there kind of qualitative essence we need to account for the redness of red, nor the manifest all-at-onceness of our percepts.

Neuron Replacement Therapy

There is a popular thought experiment that goes like this. Suppose that neurologists characterized each neuron's inputs and outputs exactly, and were able to engineer a functional equivalent. That is, an artificial device whose inner workings may or may not be similar to those of a natural neuron, but whose behavior, seen in terms of its responses to inputs, was identical to that of a neuron. Now suppose that the neurons that comprise your brain were replaced with these artificial neurons, one by one. Once your entire brain was cut over to the artificial neurons, you should have a brain system whose functioning at the neuronal level is identical to that of the brain you were born with, but whose workings are entirely artificial, and as such, able to be characterized with an algorithm of some sort.

This thought experiment (called Neuron Replacement Therapy, or NRT for short) is intended to put anti-physicalists and anti-functionalists like me in an uncomfortable position. We either have to say that the resulting artificial brain is not conscious (and if not, at what point in the gradual neuron replacement does consciousness disappear, and when it does, does it wink out all at once or fade out gradually), or we must admit that the artificial brain maintains its consciousness, and therefore full-blown consciousness is realizable by a machine.

Thoughts Are Evidence Of Mid-Level Holism

I agree that there is nothing magic about organic or biological systems. There is no reason that consciousness must be manifested in a biological system. Indeed, as a panpsychist, I think that consciousness in some form is likely manifested all the time in all kinds of matter. The problem with the thought experiment is that it begs the question - it presumes exactly the functionalist reductionism that is, in my opinion, at the heart of the matter. It assumes that what makes a brain a mind does so purely by virtue of the complex interaction of lots of blind little autonomous parts, each not knowing or caring about the others, as long as each has the right interface presented to it. No one knows the details of the relationship between neurons (as neuroscientists characterize them) and consciousness, but thoughts come whole, nose to tail. A given percept, thought, or moment of consciousness is what it is in its entirety, all at once, or not at all. It has no parts, so you can not swap some of its parts out in favor of "functionally equivalent" parts.

Functional Organization Can't Solve Panpsychism's Combination Problem

Even if a thought or percept is an example of some kind of fundamental holism occurring in nature, couldn't it still be generated in some way by the orderly, lawful interactions of smaller parts? Possibly, in some sense, but it could not turn out to simply be the orderly, lawful interactions of smaller parts, not in the way the hurricane just is the the orderly, lawlike interactions of trillions of water and air molecules. The interactions of parts may functionally emulate a percept, and they may support it somehow, or give rise to it causally, but they alone can not be it.

Assuming that there will, ultimately, turn out to be necessary relations between the physical world as we understand it and consciousness, the physical correlates of consciousness would have to display or allow for the kind of holism that our thoughts manifest. This has implications beyond the physicalists' arguments about NRT. Contrary to what Phil Goff and Luke Roelfs say, panpsychism's combination problem can not be solved by functional organization alone. Even if the quarks are seeing red, feeling pain, or craving transcendence like crazy, any aggregation of them can not be a basis for larger-scale consciousness if that aggregation is achieved through billiard ball bonking. The "integration" or "high levels" you can get out of causal poking, over time, characterized in terms of unrealized hypotheticals, can't give you the intrinsic all-at-onceness we experience, no matter how hard the quarks are rooting for us.

I want to be clear about the bullet I am biting. I think epiphenomenalism is wrong - qualitative consciousness has observable, causal powers in the physical world. Moreover, it has an inherent, indivisible unity, which is at least as weird as its qualitative aspect (that old redness of red). We either have to be orthodox physicalists, or we must embrace some freaky holism at work in the world: really-there holism, not just may-be-seen-as holism, holism that has causal implications that somehow have escaped the notice of the people in the white lab coats.

Physicalists hate this sort of thing - I have an intuition of qualitative properties, or holism, and on the basis of that intuition I make huge claims about the fundamental building blocks of the physical universe. Oh, and by the way, these claims entail causal happenings that ought to be empirically falsifiable. I appreciate the distaste for this, but I can not see how I could explain away these "intuitions" without making such claims. To twist the slogan of the New York Times, I am here to draw all the conclusions fit to draw, without fear or favor.

I am placing my bets on there being something in the physical world that manifests this, something causal that exists as a whole at a much larger scale than an electron. I am insisting on something that violates the apparent causal closure of physics, or at least bends it quite a bit. Where in the physical world might we find this kind of inherent wholeness, as opposed the to just may-be-seen-as wholeness that functional analysis of systems of parts gives us?

It has been said that the reason that so many people relate consciousness to quantum mechanics is a sort of conservation of mysteries: consciousness is mysterious, quantum mechanics is mysterious, so maybe they are the same mystery. While the connection between them is admittedly circumstantial, they are mysterious in similar enough ways that we may speculate that at the very least quantum mechanics is a promising place to look for consciousness in the natural world. (See Seager (1995) for a similar line of speculation).

First, we seek a place for consciousness at the very lowest levels of nature. As I've already argued, you can't build it out of the causal dynamics of the lower levels bonking into each other. Taking the Hard Problem seriously, I claim, forces us to be panpsychists, and that means putting consciousness (or something that scales up to consciousness as we know it) way down on the ladder of stuff in the world. Quantum mechanics is the lowest rung on the ladder, as low as our understanding of the natural world goes. It is the layer of inquiry of which we know only the behavior of the things we study, but we can not, in principle, know the intrinsic nature of whatever is doing the behaving. No one knows what an electron really is, beyond our ability to characterize its extrinsic behavior as described by the relevant quantum laws. It is at this level, following Russell, that we ought to find consciousness.

Second, and more to the present point, at least as striking as the qualitative nature of consciousness (what is it like to see red?) is the all-at-onceness of our thoughts and perceptions, their intrinsic unity. Quantum mechanics gives us some counter-examples to the orthodox reductive physicalist way of seeing everything big and complex as (mere) aggregates of tiny simple things. The very strange world of quantum mechanics is populated by bunches of things that come together to form one larger thing that can really no longer be thought of as a heap of separate components. In a quantum entangled system consisting of two particles, for example, we have multiple parts coming together to form a thing that is inherently, absolutely, one single unitary thing, whose behavior is described (and plausibly could only be described) by a single Schrödinger wave function.

Over the decades, there has been a fair amount of hand-wringing over the limits of this quantum holism. Is there just one big wave function for the entire universe? What really separates a system under study from its environment at the quantum level? These questions have not been answered to this day, but there is no doubt that some kind of real, ineliminable macroscopic holism exists out there in the physical world.

As with our percepts, a quantum entangled system is one thing, not an aggregate that may be seen as a thing when looked at or analyzed a certain way. The ontological reductionism inherent in a classical or Newtonian view of the natural world means that consciousness can not find a home in a world that is exhaustively described by such a view. Because quantum mechanics sidesteps this reductionism by providing a real basis for holism in the universe, by process of elimination, we ought to strongly suspect that consciousness and quantum phenomena are somehow related.

This idea is a version of what is called strong emergence, where truly new stuff comes into existence when you arrange low-level things in certain ways, as opposed to the weak emergence of the flock from the birds. See (Silberstein 2001) for a discussion along these lines. (With regard to consciousness, then, I am a strong emergentist, although I'm not sure I love that term. It seems a bit woolly and open-ended, and the term "emergence" might not quite capture what is ultimately going on. Moreover, it is still, in spite of the qualifying adjective, a little too adjacent to its weak sibling for my taste, given that I think that they are fundamentally different phenomena.)

Third, there is the problem of the alleged causal closure of the physical world, and the way quantum mechanics, and the holism it implies, allows us to wiggle out of it. The argument is often made that the laws of physics are airtight, that (assuming they are true) they account completely for everything that happens in the world, leaving no room for consciousness to have any measurable effect on anything. Unless, that is, you define consciousness strictly in terms of physical dynamics in the first place, which is to say that you subscribe to physicalism (and thus, in my opinion, define away the interesting questions and properties of consciousness).

Sean Carroll (Goff & Moran, 2022), for one, bangs this drum a lot. He gets a bit exasperated with us panpsychists, who claim, on the basis of our first-person intuition, that the most successful, precisely quantified theory in the history of humankind, must be wrong. He stresses that our theories of fundamental physics (the "core theory") may have some soft spots, or uncertainties around the edges, but those limits are way, way, way outside the realm of anything that happens in a human brain. The claim that the core theory is wrong at normal energy levels, in what we consider a normal gravitational field, while not logically ruled out, must clear an almost laughably high bar.

Point taken. Can we have a robustly causal panpsychism that does not so much contradict the well-established results of quantum mechanics as supplement them?

It certainly seems that the laws of quantum mechanics are true, and dead-on accurate. The loophole in the causal closure argument may be that, while perfectly accurate, the laws of quantum mechanics only yield probabilities from an empirical point of view. They specify a distribution curve, not precise predictions. They predict collective behavior with 100% accuracy, but are agnostic about individual behavior.

If you run a quantum experiment 10,000 times, you are assured that your outcomes will fit this distribution curve exactly, and for any one trial, the probability of one outcome over another is determined by the curve, but quantum mechanics is famously unable to tell the specific outcome of a particular single trial. It is an inherently indeterministic theory. Moreover, it is generally accepted that this indeterminacy is not a flaw in the theory or evidence of its incompleteness, but a fundamental feature of physical reality itself. No matter how well you know an electron's initial conditions, once it is in flight, you can not predict its position before you measure it. This is not because of any practical limitation on our ability to characterize the initial conditions of the electron, or any inaccuracy in the theory, but because the electron can not properly be said to have any definite position before you measure it. The position of the electron before you measure it is literally unknowable. It has only a likelihood of being in one place, and a different likelihood of being in another place. So the best theory we have about how the physical world behaves and most interpretations of that theory are, when it comes right down to it, indeterministic about the precise behavior of the physical world at a low level.

The only possible exception to this is the possibility that there are some kind of as-yet undiscovered "hidden variables" at work, and once discovered, they will allow us to predict the electron's position once more with Newtonian accuracy. Albert "God does not play dice" Einstein spent a great deal of his later life looking in vain for a hidden variable theory. Very few people seriously entertain the possibility of hidden variable theories today. Such theories are regarded as a philosophically (rather than scientifically) motivated attempt to restore determinism to the physical world. Even in the classical (i.e. non-quantum) world, it is becoming more apparent all the time that chaos and non-linear dynamics are the norm. Tiny differences at a low level get amplified to huge differences at a high level (as in the oft-cited butterfly effect). There is no reason, therefore, that we would need particularly large-scale quantum phenomena to have a substantial effect on the macroscopic world around us.

"Random" Is A Big Tent

People mean different things at different times by the word "random", But mathematicians have a pretty specific thing in mind when they use the term. You may have a hat containing ten cards, each with a different numeral written on it, from 0-9. You may draw cards from the hat, writing down the numeral drawn each time, then putting the card back for the next draw. It is quite unlikely, but perfectly possible, for you to draw 0123456789, or 111333555777. You could say, colloquially, that these resulted from fair "random" drawings of cards from the hat, and that therefore the resulting sequences are random. A mathematician, speaking technically, would tell you that no, those weren't random at all. The digits do not display a random distribution.

In contrast, the first digits of π are 314159265358979. Colloquially, you might say that those digits aren't random at all, since they are carved in stone, written into the fabric of the universe. But the mathematician would say, no, those are random, even though they are calculable, and derived deterministically.

When the equations of quantum mechanics say something is random, they are not making any ontological claims about how the numbers came to be; they are merely like our mathematician, observing that they display a certain conformance to a distribution curve. There are many different actual outcomes of a given set of trials of an experiment that would still perfectly fit a given distribution curve, and thus not violate any laws that were given strictly in terms of conformance to such a distribution curve. The statistical distribution of letters I type on a keyboard might be the same whether I am typing a sonnet, a recipe, or meaningless gibberish. A complex coherent pattern may have the same statistical distribution as random noise - indeed, any maximally dense information, (i.e. maximally compressed information), is statistically equivalent to random noise by definition.

The door is open, at any rate, for patterns to result from the behavior of quantum systems whose coherence is not predicted by quantum theory, but which nevertheless does not violate the predictions that quantum theory does make. We can squeeze the causal efficacy demanded by non-epiphenomenal panpsychism through a loophole in the stochastic nature of quantum predictions without actually contradicting the established theory.

So - quantum mechanics allows for the existence of high-level entities that are causally efficacious, and whose behavior, while constrained by other entities, has an element that can only be called "random" by our best third-person physical theories.

Maybe consciousness occurs in bursts, in the collapse of quantum superpositions, as Hameroff and Penrose claim. Maybe some kind of large-scale quantum superposition is sustained in the warm, wet environment of our brains by using the tubulin cytoskeleton of our neurons. Maybe not. Something like that, something crazy sounding, however, will turn out to be the case. I speculate that at some point in the future it will be discovered that the brain's activity depends crucially upon quantum phenomena, which are amplified to the level of neurons firing.

Of course, the operative word here is speculate. It is worth noting that it is only under certain special types of circumstances that quantum systems can evolve in a state of entanglement or superposition without decohering or collapsing back to a classical state (leaving aside the philosophical thicket of the measurement problem). Under ordinary circumstances, we do not see quantum systems of any great scale (I avoid using the word "complexity" because it implies precisely the wrong thing, namely that a quantum system is made of parts, and that there may be fewer or more of those parts). So like Hameroff, I suspect that we will eventually find structures in the brain that would support some reasonably large-scale quantum superposition which implies isolation from the surrounding environment.

But Back To NRT

Physical systems in states of quantum entanglement display holism that I claim is a non-negotiable necessity for instantiating consciousness. Further, I have speculated that as quantum mechanics contains the only currently known gap in the causal closure of the physical, the indeterminacies of quantum mechanics are, in fact, the fence around these natural individuals that modern science has built, with a sign that says, "Something funny is going on in here, and we can never know what".

For the moment, however, let us set aside my suspicions about quantum mechanics. Perhaps my speculations about quantum mechanics are completely wrong. Perhaps consciousness is some kind of hitherto undiscovered field or force that is modulated or generated by neurons. Maybe Gregg Rosenberg is right, and consciousness is built into the mesh of causation itself. Moreover, no matter how this question is answered, the quantum superposition or force or field that is consciousness could be something that spans lots of neurons, as Hameroff and Penrose believe, or it could be something that happens inside a single neuron, as suggested by Jonathan Edwards.

Whatever kind of physical phenomenon thoughts, percepts, or moments of consciousness turn out to be at the most fundamental level, neurons have evolved to generate or exploit this phenomenon in some way. But it must be they, (these fields, forces, superpositions, collapses thereof, or whatever) that instantiate consciousness in the senses I am interested in for the purposes of this book: the redness of red, and the holistic unity of our thoughts and percepts. The missing physical link is something weird, and not the supporting neuronal infrastructure.

If the the artificial neurons in the NRT thought experiment can also exploit or generate these things, then great - consciousness is preserved in the artificial brain. If not, not, and the NRT thought experiment fails. If the field or force or superposition or whatever physical blob that instantiates this holistic consciousness spans multiple neurons, it will not be something that can be carved up and characterized in terms of quantifiable inputs and outputs between neurons. In such a case the NRT hypothesis is untenable.

If, on the other hand, the stuff of consciousness (force, field, whatever) happens inside individual neurons, it could be that the artificial neurons will not be able to emulate natural neurons with an explicitly specified algorithm. In this case, the non-algorithmic stuff in the neuron guides the neuron's behavior in non-algorithmic ways. Otherwise, if the stuff in the neuron is emulatable with an algorithm (the epiphenomenal case) the end result of NRT will be a zombie. All of its neuronal behaviors and motor outputs will be identical to those of a conscious mind, but it will not, in fact, be conscious, at least in the "what is it like to see red" sense.

Either way, whether whatever instantiates consciousness spans neurons or is somehow curled up inside an individual neuron and manifests itself causally only by influencing how and when the neurons fire, there is something weird going on, something physically weird. I am flatly claiming, in Patricia Churchland's phrase, that there is "pixie dust in the synapses", except that it's even worse than that. In past chapters, I have emphasized the qualitative aspects of the pixie dust, which implicitly leaves open the possibility of a more benign, conservative panpsychism: there is weirdness, but the weirdness might be confined to the crumbs of physical reality, and everything scales up according to the usual rules of causal dynamics that describe how reality stacks neatly. Here I am going a bit further in my claims about the pixie stuff. It's not just dust. Maybe pixie clumps, or pixie blobs. Moreover, as with the redness of red, for the same reasons, epiphenomenalism is false: the pixie blobs influence (or even constitute) our cognition, and have macroscopic causal effects on the world. The pixie blobs do stuff.

This entails taking realism about consciousness to a new level. There is more to the mystery of phenomenal consciousness than accounting for some kind of qualitative paint that coats the otherwise coldly cognitive objects and data structures in our minds. Qualia are not just unstructured sensory qualities, but the objects themselves as well. To the extent that this essential objecthood is perceptible to us, and figures into our cognitive lives (i.e. to the extent that epiphenomenalism is just as false with regard to this wholeness-quale as it is with regard to the redness of red) this must go all the way down. The way we think of physics must accommodate it.