Saturday 5 February 2022

Applying Illusionism to Physical Reality

Many of you would be aware already of illusionism, if in fact there were many readers of this blog. But in case it's needed, illusionism, exemplified by Keith Frankish and Daniel Dennett, is an approach to the philosophy of consciousness which claims that qualia (the ineffable irreducible feelings associated with conscious experience, e.g. the redness of red), are entirely illusory and do not actually exist. As such, on this view the Hard Problem of Consciousness as defined by David Chalmers simply dissolves -- we need only explain why we believe we experience qualia, we do not need to explain how it is that qualia can be produced by physical stuff. As a bonus, illusionism may claim that even the idea of qualia are incoherent.

Illusionism is, I would say, a species of functionalism, and so is compatible with and largely overlaps with other glosses on functionalism such as computationalism. There may be corner cases where some illusionists may disagree with some computationalists, especially on how best to describe things, but the stories they tell about human consciousness are mostly compatible. As such, I count myself as an illusionist, a functionalist and a computationalist.

What I wanted to write about today is a strong rhyming I've noticed between the illusionist view of consciousness and how I think of the stuff of physical reality.

The idea that reality itself is fundamentally structural and nothing more is a view known as Ontic Structural Realism (OSR), as exemplified by James Ladyman and Don Ross in the academic book Every Thing Must Go: Metaphysics Naturalized. I've written about a related idea from Max Tegmark on this blog before, the Mathematical Universe Hypothesis (MUH). The MUH is in my view just a slightly stronger claim than OSR. While OSR asserts that all that physically exists is structure (in the mathematical sense), the MUH proposes that not only is our universe a structural/mathematical object, but that it only exists at all in an abstract platonic* sense. On the MUH, the universe appears to be physical to us just because we are in it, and as a corollary all other possible universes exist in the same way (I don't think OSR tends to emphasize or necessarily accept this multiverse idea if it is discussed at all). As noted previously, I accept the MUH which means I'm also committed to OSR.

I see a number of parallels here between OSR/MUH and illusionism, so much so that I feel that to be consistent anyone who accepts one should perhaps accept the other. More precisely, I think illusionism/computationalism implies the MUH. As such, you could take this to be an argument for the MUH if you are an illusionist, or an argument against illusionism/computationalism if you reject the MUH.

The parallels I see come into focus most sharply if I construe the MUH view in particular to be eliminating the concept of objective physical existence, or at least deflating it in much the same way that illusionists deflate qualia/consciousness. But even the weaker OSR eliminates a similar concept -- that the structure of reality needs non-structural "physical stuff" to ground it.

Parallel Illusionism OSR / MUH
Illusion Qualia as we intuitively conceive of them are illusory. Physical stuff/existence as we intuitively conceive of it is illusory.
Explanation We don't need to explain how qualia arise. We only need to explain why we perceive them to exist. We don't need to explain what "breathes fire into the equations" of physics or why this world physically exists, or what physical stuff really is. We only need to explain why we perceive it as existing physically.
Substrate independence Consciousness is substrate independent. Physical reality is so substrate independent it doesn't even need a substrate!
Abstractness Consciousness is realised by and characterised by certain kinds of "functions" rather than certain kinds of stuff, and so is analogous to software, making it somewhat abstract in nature. Our physical reality is realised by certain kinds of structural relations rather than certain kinds of relation-bearing stuff, making it somewhat abstract in nature.
Zombies With regard to philosophical zombies (a thought-experimental entity physically identical to us but which does not experience consciousness), we have two options. We can either say that zombies are inconceivable and cannot exist in any possible world, or we can go in completely the opposite direction and say that we are all zombies. These are just two ways of expressing the same fundamental idea -- that illusionism collapses the distinction between humans and zombies. So we can say that either we're all humans or we're all zombies because there is no difference. The concept that we use to distinguish between them, namely phenomenological consciousness, is rejected. On the MUH, if not OSR, the parallel to a philosophical zombie is a possible world which does not physically exist, which I will call a "zombie world" (a possible world is any world which could exist or could have existed without contradiction or incoherency). With regard to zombie worlds, we have two options. On the MUH, we can either say zombie worlds are inconceivable, or we can say that all possible worlds (including this one) are zombie worlds. Either all worlds are physical or all worlds are abstract because there is no difference. The concept that we use to distinguish between them, namely objective physical existence, is rejected.
Privacy The problem of other minds is that it isn't possible to determine empirically if other beings are conscious because consciousness is intrinsically subjective. One might therefore say that there is no such thing as objective consciousness. We are only really conscious from our own point of view. On functionalism, we should assume that entities that process information much as we do are likewise conscious (if only to themselves). The problem of other worlds is that it isn't possible to determine empirically if other causally-disconnected universes physically exist. One might therefore say that there is no such thing as objective physical existence. A world only really physically exists from a point of view within it. On the MUH, we should assume that other possible worlds are likewise physical (if only from points of view within).
Objection! Illusionists are not impressed by the objection "How can we perceive an illusion in the first place if we are not conscious?". This is because they believe that we can give a functional account of beliefs and perception. MUH proponents are not impressed by the objection "How can we perceive an illusion in the first place if we do not physically exist?" This is because they believe that we can be grounded in a platonic mathematical account of existence.

Again, the parallels seem so strong to me I guess it's no wonder I'm attracted to both illusionism and the MUH. But I wonder how one could accept one without accepting the other, and I think most illusionists probably do reject the MUH. As an example, while not an illusionist per se, I know Sean Carroll is somewhat sympathetic to illusionism but seems to regard the MUH as nonsense. I'd love to know what Frankish or Dennett think of it but I haven't seen anything from them on it.

But it goes further than that this curious extended analogy. As I've written before, there is a potentially fatal flaw with computationalism which I think can only be resolved by recourse to the MUH or some other sort of modal realism (the idea that all possible worlds physically exist). So in my view, illusionists should also be MUH proponents to be consistent, and computationalists should also be MUH proponents to be coherent.

* I prefer small-p "platonic" to big-P "Platonic" to indicate that I don't necessarily buy into much of Plato's philosophy and I'm just using it as a useful adjective for mathematical realism.

9 comments:

  1. An interesting post DM!

    I am a functionalist and computationalist (both in terms of mind and reality overall), but not an illusionist. I think qualia exist, but not in any non-physical sense, only as what they're described to be, instances of subjective experience, that is, instances of our nervous system's categorizing conclusions about states of affairs. Under this view, the illusion of qualia are qualia. But as we've discussed before, this may be a semantic difference.

    Interestingly enough, I just did a post on criteria for being real, one of which is causal power (based on Chalmers' book Reality+). It didn't occur to me to apply them to qualia. But the fact that we can discuss the redness of red seems to indicate that the redness of red, and other phenomenal properties, have causal effects on our behavior. Although qualia are not independent of the mind, another criteria, so I could see someone rejecting it for that reason.

    But if I apply the same criteria to abstract mathematical entities, it seems like they do worse, failing both tests. That doesn't necessarily mean that they don't exist, only that I seem to have a method to establish the existence of qualia without establishing that of platonic entities.

    But this is my initial take on it. I might have a different opinion after more thought. Anyway, excellent post!

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    1. Thanks Mike!

      I think what you believe exist are either what Frankish calls Diet Qualia or Zero Qualia, as opposed to Classic Qualia. See https://keithfrankish.github.io/articles/Frankish_Quining%20diet%20qualia_eprint.pdf or this video, starting from 45:46 -- https://youtu.be/jXNXewKcDM4?t=2746

      Classic qualia are the kind of ineffable qualia we cannot ever explain with science and motivate the likes of Goff to panpsychism.

      Zero Qualia are basically what is left when we eliminate the phenomenal aspects of qualia entirely -- so it's the functional side of it. Frankish is happy to accept that Zero Qualia exist, but he would say it's a bit of a misnomer to regard it as a type of quale because the whole point of the word "quale" is supposed to pick out something phenomenal rather than functional.

      Diet qualia are something in between these extremes. Frankish denies that Diet Qualia exist, for reasons explained at length in the paper above. Basically, he argues that they either collapse to Zero Qualia or Classic Qualia based on how you answer various challenges. I see another parallel here, BTW -- this is rather like the situation of denying libertarian free will which is supposed to be some diet intermediate position between classic causation and zero causation.

      To the extent that qualia have causal power, they are not really qualia at all. Zero qualia have causal power, but the actual phenomenality of real classic qualia does not. We cannot appeal to qualia to explain why we discuss the redness of red. This is why I reject (classic) qualia altogether -- they are explanatorily useless.

      I've read your blog post on criteria for reality and enjoyed it, thanks!

      Causal power makes sense as a criterion for things to physically exist. But then I hold that objective physical existence is incoherent, and physical existence is a subjective property. So mathematical substructures may indeed have causal power, but only from points of view within the same overall structure.

      Take the example of a billiard ball having the causal power to strike another. We both agree that these are physical objects, even if to me this is a statement about our relationship to them rather than anything objectively true about them. To me, these are both ultimately mathematical substructures within a mathematical universes, so these are examples of mathematical objects that appear to us to have causal powers, unlike say a quadratic equation in a high school maths textbook. So there is a way to reconcile causal powers as a criterion for physical existence with the MUH.

      I do also think that mathematical objects are mind-independent, but let's leave that for now!

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    2. I actually did a post a while back on an earlier talk Frankish gave with basically the same content (which I think we had a good conversation on). The quick summation is I think the issue isn't some classic vs diet or zero version of qualia. It's failing to remember that qualia are subjective, not objective, something it seems non-physicalists forget in their takeaways from qualia, and illusionists fail to recall in their rebuttals.

      When we remember that they're only subjective, only about the phenomenal, that is how they seem, then our impression that they exist, the illusion of qualia, including their illusory aspects, are qualia. To say that there is an illusion of qualia is just to say that there are qualia.

      Now, if we want to say that the objective processing that leads to the impression of qualia is radically different from naive inferences from that subjective perspective, then I’m onboard. But I think we need to be more careful with our language.

      The main thing causal power seems to get at is whether something is real for us. If a system of things have causal powers among themselves, but have never had or will have any with us, then they remain abstract for us. The key phrase here is “for us”. The question of the MUH, it seems to me, is whether it makes sense to speak of things as being real if they’re never real for us.

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    3. Thanks Mike,

      You're right that we did go through this before (I'd forgotten!) and I should re-read that discussion.

      But, quickly, how would you distinguish your position from "There are only Zero Qualia"?

      > The question of the MUH, it seems to me, is whether it makes sense to speak of things as being real if they’re never real for us.

      Yeah, but then we're not real from the point of view of people in other universes. As I say in the blog post, from the MUH point of view you can either say we're all real or none of us are.

      I don't think illusionists forget that qualia are subjective.

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    4. Hi DM,

      Here’s Frankish’s definition of classic qualia in the paper:
      “Classic qualia
      Introspectable qualitative properties of experience that are intrinsic, ineffable, and subjective. ”

      My only issue with this description is it lists the subjective aspect as the last of many properties. Instead, I’d word it as:

      Qualia
      Subjectively introspectable qualitative properties of subjective experience that are subjectively intrinsic, and subjectively ineffable.

      Here’s Frankish’s definition of diet qualia:
      “Diet qualia
      The phenomenal characters (subjective feels, what-it-islikenesses, etc.) of experience.”

      I’ll be honest. I’m not sure which version mine matches up best against. But mine does retain a version of the classic attributes, just emphasizing that all of them are subjective.

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    5. Hi Mike,

      You left out Zero Qualia:

      "The properties of experiences that dispose us to judge that experiences have introspectable qualitative properties that are intrinsic, ineffable, and subjective."

      If you're saying the illusion of qualia are qualia, then that sounds to me like saying that all qualia are Zero qualia, because what is an illusion but a set of properties of an experience that dispose us to make (false) judgements?

      You may say that the judgement is not false, but here I'm quoting you apparently conceding that there's an illusion at play, and illusions involve false judgements.

      OK, so you can say that it's not actually an illusion because these judgements are correct since there are qualia of a sort after all, in which case we can revise what you said to be "the seeming-to-be-ness of qualia are the qualia", in which case I would just say that the "seeming-to-be-ness" of qualia are just those properties of experiences that dispose us to make the judgements that there are qualia.

      I don't think diet qualia are particularly well-defined, and that's what Frankish actually argues. So I wouldn't pay too much attention to the definition. It's just supposed to be something more than zero qualia and something less than classic qualia.

      I prefer Frankish's definition of classic qualia, because I cannot make sense of what it means for something to be subjectively intrinsic or subjectively ineffable. It's either intrinsic or it isn't. It's either ineffable or it isn't. Subjectivity is a separate issue, meaning that it is only perceived at all by the subject. If you want to emphasize that subjectivity is the most important property of qualia, then OK, but I wouldn't do so by turning it into an adverb attached to every other property.

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    6. Thanks DM. I did miss Zero Qualia.

      I think the phrase "properties of experience" is interesting, because another way to say that is "qualities of experience", or "qualia". It just goes to show how much of a definitional dispute this is, at least among physicalists. For that matter, I think the word "illusion" in this context is just another more provocative way of saying "subjective."

      Ultimately it's the difference between a reductionist and an eliminative reductionist, between someone who accepts emergence (in the weak sense) and someone who doesn't.

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  2. Having been studying consciousness (in an amateur way) for some years, I am now thinking more about metaphysics and the nature of reality, and would agree that the one sheds more light than might be expected upon the other. One element of this is that both are about putting two things in relation to each other (e.g. me and the thing I am conscious of; me and the thing that is real to me).

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