Consciousness and Downward Causation

For many people, the phenomenon of consciousness is the best evidence we have that there must be something important missing in our basic physical description of the world. According to this worry, a bunch of atoms and particles, mindlessly obeying the laws of physics, can’t actually experience the way a conscious creature does. There’s no such thing as “what it is to be like” a collection of purely physical atoms; it would lack qualia, the irreducibly subjective components of our experience of the world. One argument for this conclusion is that we can conceive of collections of atoms that behave physically in exactly the same way as ordinary humans, but don’t have those inner experiences — philosophical zombies. (If you think about it carefully, I would claim, you would realize that zombies are harder to conceive of than you might originally have guessed — but that’s an argument for another time.)

The folks who find this line of reasoning compelling are not necessarily traditional Cartesian dualists who think that there is an immaterial soul distinct from the body. On the contrary, they often appreciate the arguments against “substance dualism,” and have a high degree of respect for the laws of physics (which don’t seem to need or provide evidence for any non-physical influences on our atoms). But still, they insist, there’s no way to just throw a bunch of mindless physical matter together and expect it to experience true consciousness.

People who want to dance this tricky two-step — respect for the laws of physics, but an insistence that consciousness can’t reduce to the physical — are forced to face up to a certain problem, which we might call the causal box argument. It goes like this. (Feel free to replace “physical particles” with “quantum fields” if you want to be fastidious.)

  1. Consciousness cannot be accounted for by physical particles obeying mindless equations.
  2. Human beings seem to be made up — even if not exclusively — of physical particles.
  3. To the best of our knowledge, those particles obey mindless equations, without exception.
  4. Therefore, consciousness does not exist.

Nobody actually believes this argument, let us hasten to add — they typically just deny one of the premises.

But there is a tiny sliver of wiggle room that might allow us to salvage something special about consciousness without giving up on the laws of physics — the concept of downward causation. Here we’re invoking the idea that there are different levels at which we can describe reality, as I discussed in The Big Picture at great length. We say that “higher” (more coarse-grained) levels are emergent, but that word means different things to different people. So-called “weak” emergence just says the obvious thing, that higher-level notions like the fluidity or solidity of a material substance emerge out of the properties of its microscopic constituents. In principle, if not in practice, the microscopic description is absolutely complete and comprehensive. A “strong” form of emergence would suggest that something truly new comes into being at the higher levels, something that just isn’t there in the microscopic description.

Downward causation is one manifestation of this strong-emergentist attitude. It’s the idea that what happens at lower levels can be directly influenced (causally acted upon) by what is happening at the higher levels. The idea, in other words, that you can’t really understand the microscopic behavior without knowing something about the macroscopic.

There is no reason to think that anything like downward causation really happens in the world, at least not down to the level of particles and forces. While I was writing The Big Picture, I grumbled on Twitter about how people kept talking about it but how I didn’t want to discuss it in the book; naturally, I was hectored into writing something about it.

But you can see why the concept of downward causation might be attractive to someone who doesn’t think that consciousness can be accounted for by the fields and equations of the Core Theory. Sure, the idea would be, maybe electrons and nuclei act according to the laws of physics, but those laws need to include feedback from higher levels onto that microscopic behavior — including whether or not those particles are part of a conscious creature. In that way, consciousness can play a decisive, causal role in the universe, without actually violating any physical laws.

One person who thinks that way is John Searle, the extremely distinguished philosopher from Berkeley (and originator of the Chinese Room argument). I recently received an email from Henrik Røed Sherling, who took a class with Searle and came across this very issue. He sent me this email, which he was kind enough to allow me to reproduce here:

Hi Professor Carroll,

I read your book and was at the same time awestruck and angered, because I thought your entire section on the mind was both well-written and awfully wrong — until I started thinking about it, that is. Now I genuinely don’t know what to think anymore, but I’m trying to work through it by writing a paper on the topic.

I took Philosophy of Mind with John Searle last semester at UC Berkeley. He convinced me of a lot of ideas of which your book has now disabused me. But despite your occasionally effective jabs at Searle, you never explicitly refute his own theory of the mind, Biological Naturalism. I want to do that, using an argument from your book, but I first need to make sure that I properly understand it.

Searle says this of consciousness: it is caused by neuronal processes and realized in neuronal systems, but is not ontologically reducible to these; consciousness is not just a word we have for something else that is more fundamental. He uses the following analogy to visualize his description: consciousness is to the mind like fluidity is to water. It’s a higher-level feature caused by lower-level features and realized in a system of said lower-level features. Of course, for his version of consciousness to escape the charge of epiphenomenalism, he needs the higher-level feature in this analogy to act causally on the lower-level features — he needs downward causation. In typical fashion he says that “no one in their right mind” can say that solidity does not act causally when a hammer strikes a nail, but it appears to me that this is what you are saying.

So to my questions. Is it right to say that your argument against the existence of downward causation boils down to the incompatible vocabularies of lower-level and higher-level theories? I.e. that there is no such thing as a gluon in Fluid Dynamics, nor anything such as a fluid in the Standard Model, so a cause in one theory cannot have an effect in the other simply because causes and effects are different things in the different theories; gluons don’t affect fluidity, temperaturs and pressures do; fluids don’t affect gluons, quarks and fields do. If I have understood you right, then there couldn’t be any upward causation either. In which case Searle’s theory is not only epiphenomenal, it’s plain inaccurate from the get-go; he wants consciousness to both be a higher-level feature of neuronal processes and to be caused by them. Did I get this right?

Best regards,
Henrik Røed Sherling

Here was my reply:

Dear Henrik–

Thanks for writing. Genuinely not knowing what to think is always an acceptable stance!

I think your summary of my views are pretty accurate. As I say on p. 375, poetic naturalists tend not to be impressed by downward causation, but not by upward causation either! At least, not if your theory of each individual level is complete and consistent.

Part of the issue is, as often happens, an inconsistent use of a natural-language word, in this case “cause.” The kinds of dynamical, explain-this-occurrence causes that we’re talking about here are a different beast than inter-level implications (that one might be tempted to sloppily refer to as “causes”). Features of a lower level, like conservation of energy, can certainly imply or entail features of higher-level descriptions; and indeed the converse is also possible. But saying that such implications are “causes” is to mean something completely different than when we say “swinging my elbow caused the glass of wine to fall to the floor.”

So, I like to think I’m in my right mind, and I’m happy to admit that solidity acts causally when a hammer strikes a nail. But I don’t describe that nail as a collection of particles obeying the Core Theory *and* additionally as a solid object that a hammer can hit; we should use one language or the other. At the level of elementary particles, there’s no such concept as “solidity,” and it doesn’t act causally.

To be perfectly careful — all this is how we currently see things according to modern physics. An electron responds to the other fields precisely at its location, in quantitatively well-understood ways that make no reference to whether it’s in a nail, in a brain, or in interstellar space. We can of course imagine that this understanding is wrong, and that future investigations will reveal the electron really does care about those things. That would be the greatest discovery in physics since quantum mechanics itself, perhaps of all time; but I’m not holding my breath.

I really do think that enormous confusion is caused in many areas — not just consciousness, but free will and even more purely physical phenomena — by the simple mistake of starting sentences in one language or layer of description (“I thought about summoning up the will power to resist that extra slice of pizza…”) but then ending them in a completely different vocabulary (“… but my atoms obeyed the laws of the Standard Model, so what could I do?”) The dynamical rules of the Core Theory aren’t just vague suggestions; they are absolutely precise statements about how the quantum fields making up you and me behave under any circumstances (within the “everyday life” domain of validity). And those rules say that the behavior of, say, an electron is determined by the local values of other quantum fields at the position of the electron — and by nothing else. (That’s “locality” or “microcausality” in quantum field theory.) In particular, as long as the quantum fields at the precise position of the electron are the same, the larger context in which it is embedded is utterly irrelevant.

It’s possible that the real world is different, and there is such inter-level feedback. That’s an experimentally testable question! As I mentioned to Henrik, it would be the greatest scientific discovery of our lifetimes. And there’s basically no evidence that it’s true. But it’s possible.

So I don’t think downward causation is of any help to attempts to free the phenomenon of consciousness from arising in a completely conventional way from the collective behavior of microscopic physical constituents of matter. We’re allowed to talk about consciousness as a real, causally efficacious phenomenon — as long as we stick to the appropriate human-scale level of description. But electrons get along just fine without it.

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421 Responses to Consciousness and Downward Causation

  1. Don Flood says:

    I think that Professor Giulio Tononi has the answer:

  2. eric says:

    It’s the idea that what happens at lower levels can be directly influenced (causally acted upon) by what is happening at the higher levels. The idea, in other words, that you can’t really understand the microscopic behavior without knowing something about the macroscopic.

    I think you are right in saying – later than this quote – that the main problem is when people switch between descriptive levels, because to me, even your description above has an aspect of that. I read the first quoted sentence and thought to myself “of course it can! An atom is influenced by whether its in the solid or liquid state, because its influenced by the proximity, type, number, energy etc. of surrounding atoms, and that’s what a phase description is – a statement about the proximity, number, etc.. of surrounding atoms.” If you give me two atoms of the same kinetic energy in a solid and a liquid (or in different solids), and I hit them with the same photon, they are going to react differently because their bonding is different.

    But then I read your second paragraph, and I saw that what I was thinking about as counting as ‘higher level’ (i.e., phase, characteristics of the surrounding atoms), fits easily into your category of microscopic.

    I’m guess Searle is making something of the same mistake. He’s not getting that “hammer” and “nail” can be so well described microscopically that the result of an impact can be fully worked out at that level, and the need for a macroscopic extra description just isn’t there. The macro view is convenient shorthand, for sure, but it doesn’t add anything that would be missing from a full micro description.

  3. Michael Carasik says:

    Isn’t the case of observation causing a quantum field to collapse a case of downward causation?
    (Forgive the layman’s language here.)

  4. Ben Goren says:


    I’m unsurprisingly completely on board with you with respect to everything you wrote in this blog post. Where I would part ways with you is when you use the language of “Free Will” as a valid emergent-level explanation for human behavior.

    Let me propose a trivial real-world experiment you can perform right now that should dissuade you of the notion of “Free Will,” in whatever form you might conceive of. All you’ll need is a pencil or pen and a piece of paper, or the modern electronic equivalents, or some other variation on the theme.

    And the experiment itself is trivial: write something down. Anything; it doesn’t matter. You might write your favorite number, quote your favorite poem, jot down Boltzmann’s Equation (which is what I’d predict of you), draw a cat, scribble randomly — whatever you like.

    Go ahead and do so, and please don’t continue reading until after you’re satisfied you’re done.

    In all forms of all definitions of the term, “Free Will,” an essential element of the definition is the idea that one can do otherwise in a given situation. For traditional religious libertarians, this is foremost, and is often the explanation for the existence of evil despite the contrary desires of the gods. For compatibilists such as you, it takes the form of observing that we typically imagine ourselves performing some different action either before or after the fact.

    Now, take a look at the piece of paper you marked. Right there is overwhelming evidence that, perceptions to the contrary, you really only did perform that particular action. Given the circumstances at the time you put pencil to paper, the markings you now observe are the inevitable result.

    In different circumstances, might you mark something else? Sure, of course — but that’s no more remarkable a statement than that a ball dropped from a different height will take a different amount of time to reach the floor. And did you previously and can you now imagine marking something else? Again, yes — but you can also imagine being sprinkled with faery dust and flying off to the fourth star on the right where you fight an hook-armed pirate. We don’t consider it remarkable that different circumstances lead to different outcomes, and we don’t judge reality based upon how vividly we can imagine something.

    You, Sean, as a Laplacian physicist, should especially appreciate this: given the state of the universe at the moment when you started to read my response and the complete laws of physics, whatever you put on the page was inevitably predictable. Change the state to something different, and your reaction would be comparably different.

    We have the perception of being able to freely alter the course of history, but only because we imagine doing so as part of our contemplative decision-making process. But even in that context, it’s plain that it’s all illusory: we’ve all plenty of times reacted unconsciously in all sorts of situations, from blinking at something suddenly appearing moving to our faces, to maneuvering to catch a thrown ball, to a later-regretted angry retort, to pushing somebody out of the path of danger. And when taking time to make a decision, the decision-making process is itself entirely deterministic, with our thoughts unfolding according to the state of the Universe and its physics just as everything else does.

    “Free Will” inevitably attempts to assert a pre-Copernican anthropocentric specialness to humans, that we have some sort of influence upon the Universe that is unique to humanity. In reality, we’re no different from anything else, save that we happen to have rather detailed recursive simulations of the universe running in our brains. And we’re not even unique in that respect, even if our simulations are more detailed than any other we’re aware of; even thermostats have simplistic maps of external reality.

    When you embrace the irrefutable fact that consciousness is nothing more than a locally detailed real-time map of the Universe perpetually centered around the “You Are Here” marker, a map that includes the map itself, marker and map of the map of the map and all, the philosophical “specialness” that we’re told we must explain with magic evaporates in a puff of rhetorical smoke.



  5. Physicalist says:

    Ben Goren: You are mistaken when you claim, “In all … definitions of the term, “Free Will,” an essential element … is the idea that one can do otherwise.”

    This is false. Most Philosophy 101 classes discuss compatibilism, which standardly defines freedom as “doing what you want” with the explicit absence of any reference to the ability to do otherwise.

  6. John Merryman says:

    I see upward and downward causation as explaining how consciousness and its expressive manifestations work, without really explaining them. They are a feedback loop between different, interconnected layers, such as between trees and forest, content and context. Though when you try to explain significantly different layers, say quantum mechanics to biological functions, they are too far apart, in terms of direct feedback, to be particularly explanatory.
    One basic dichotomy to consider would be between the generic concepts of energy and information. In that energy manifests and motivates form, while form defines and describes the constituent energy. Can anyone think of actual form/information that is not being manifested by some quantity of energy, or energy not expressing some degree of of form, even if just amplitude and frequency?
    The difference between the two is that energy is dynamic, while form is static. Again, does anyone know a form of energy that is not at least potentially dynamic, or form that the more dynamic it is, the more fuzzy its definition?
    So energy is continuously creating and dissolving form. Now when we apply this to consciousness, as well as biology, given the origins of consciousness would seem to be an inner experience of biology, even if very simple and basic, the effective forms are individual organisms, or specific thoughts/feelings.
    So just as biology is dynamically creating and shedding generations of biological forms, so too does consciousness create and shed sequences of thought patterns. Just as we, as individuals, move through the environment, absorbing and shedding energy.
    As such consciousness would seem to be a type of energy, while the forms it manifests, whether biological organisms, or thought patterns, are the forms being manifest by the process.
    This doesn’t explain consciousness, or biology, but instead of two mysteries, it might help to combine them into one and relate the process to the specific expression.
    When science and math can’t fully explain a phenomena, they usually declare it an axiom and work around it, hoping further explanations will arise. With consciousness and biology, they are so obviously front and center of our own experience, they are difficult to simply put on the back shelf and work around, though that may be the only immediate solution.

  7. Sean Carroll says:

    Michael Carasik– No, it isn’t. “Observation” in quantum mechanics is just a suggestive word meaning “interaction between a quantum system and another quantum system, especially in the case where the second system includes many environmental degrees of freedom that are not explicitly accounted for.”

    Ben and Physicalist– Of course I could have done otherwise if the microstate of my quantum fields were different (even if the coarse-grained macrostate was the same). So I certainly could have done otherwise, consistent with all the information I actually have but no other information.

  8. Ben Goren says:

    Most Philosophy 101 classes discuss compatibilism, which standardly defines freedom as “doing what you want” with the explicit absence of any reference to the ability to do otherwise.

    That’s either libertarian or Orwellian.

    If freedom is doing what you want, then it’s also the freedom to not do what you don’t want — leaving you free to do either but to choose the one you want. That’s pure libertarianism.

    But if freedom is doing the one thing you want to do without any ability to do anything else, that’s the freedom of the happy slave who loves his wise master. More colorfully, it’s the factory paint choice of a Model T Ford: whatever you want, so long as what you want is black.



  9. Dear Professor Carroll,

    I believe that Einstein’s prescience, in his quote about reality and illusion, has much to say on this subject. If we take his quote and parse it into two categories this becomes clearer; ( Reality is )(merely an illusion, albeit a persistent one). Whatever the universe is, it is real; it is the nature of this ‘is’ that we seek answers to. The persistent illusion is nothing other than consciousness itself. I don’t want to get into the question of the nature of consciousness here, other than to point out that the only way conscious observers know anything at all about Reality is via the process of our bio-sensory system. This system creates for us an ‘experience’ of reality from our interactions with actual Reality. This experience is a biological/biochemical interpretation of that interaction. It is also absolute, no part of the biologically interpreted experience of reality is actual Reality itself, it is wholly a product of our biology, and as such, is incapable of creating that experience from anything other than the sense organs and central nervous system that biology has given us. This system is qualitatively and quantitatively incapable of reporting on the full gamut of actual Reality. Just as our sense of sight encompasses a minuscule slice of the electromagnetic spectrum, so every experience of biology created by our limited senses does the same. We no longer marvel that there is more spectrum than we can see or more frequencies than we are able to hear, but some experiences are sacrosanct, and we believe our experiences of them to be equal to what actual Reality is. These sacrosanct experiences are our experience of a ‘now’ moment and the experience of a ‘flow’ of time. Because ALL of our experiences of reality are a bio-sensory creation, manufactured within our central nervous system, our experience of the reality of a ‘now’ and a ‘flow’ of time are as well.
    We are an organism that is completely dependent on actual Reality for our being, that is, our ‘is’, but that Reality is not dependent on the experiences we have of It in any way. Whatever actual Reality may ‘be’ it is not circumscribed by what our experiences tell us about it, and that includes our experiences of a ‘now’ and of ‘flowing’ time. J Joseph Kazden has written a book called TotIs that describes this, and more, in greater detail.
    With Kind Regards
    Bob Carlson

  10. Ben Goren says:

    Ben and Physicalist– Of course I could have done otherwise if the microstate of my quantum fields were different (even if the coarse-grained macrostate was the same). So I certainly could have done otherwise, consistent with all the information I actually have but no other information.

    But that would mean that Schrödinger’s Cat has the freedom to live or die, or that any given ball in a billiards break has the freedom to go in any of the pockets. Your “Free Will” is an expression of ignorance, not of freedom. We don’t think of the inescapable ignorance of quantum entanglement or the practical ignorance of chaotic Newtonian physics as free in the sense used by “Free Will,” so why should it apply to humans?



  11. John Merryman says:


    What is “will,” other than a conscious determination? What is it free of? Input? Than wouldn’t it be equally free of output, i.e. consequence?

    The problem with assuming determinism is that it assumes the input into any given situation can be theoretically known before the event occurs, but the input into any event comes from multiple directions, at finite speeds. So one would have to then assume a “God’s eye view,” outside of space and time, to know all input. Acts have to occur, in order to be determined. Events are first in the present, then in the past.
    Will is our input into the course of action.

  12. Kevin Henderson says:

    Hi Ben,

    You should change “inevitably predictable” to “inevitably unavoidable”. I can write down something just as well on a piece of paper and there’s no person on the planet…not even Elon Musk coordinating all the supercomputer AI (ha!) power of the human species could predict what I write on the paper…ok maybe 1/10^80 chance.

    Here’s another example why our universe which has no free will (i.e., completely determined) is indistinguishable from a universe that has free will. Predict the location where any of my cats will be tomorrow at noon to within a centimeter. If the cats had free will we may not be able to ever know what they will decide based on physics. If they do not have free will we should in principle be able to predict their actions via physics. Unfortunately, we do not have the knowledge to predict such things.

    Here’s another. Mark one molecule of water and place it in the Pacific. Tell me where it will be in one week to within a meter. That water molecule’s behavior is completely determined but wholly indistinguishable from a water molecule that could have free will.

    (Sean, this entry on consciousness is thought provoking.)

  13. Sean Carroll says:

    Ben– For the same reasons that every person, in actual conversation, speaks about human beings as making choices. It’s the best way we have of talking about human beings. Nothing is gained, and much is lost, by abandoning such talk and simply saying “I don’t know the microstate of all your particles, but if I did your behavior would be determined, so there’s no such thing as choice.”

  14. Physicalist says:

    Ben: When you say “freedom to not do …” You are misconstruing the position because you’ve thrown freedom into the definition of (or criterion for) freedom.

    Sean: As it happens, I agree with you (see, e.g. here: ).

    But the usual compatiblilst position nonetheless claims that the ability to do otherwise is irrelevant to freedom (and may itself be undesirable or even incoherent).

    That said, I think you and I agree on all matters of substance.

  15. Patrice Ayme says:

    It seems to me that Downward Causation is inherent to the standard Copenhagen Interpretation of Quantum Physics. Indeed that interpretation distinguishes between the Quantum computation and the classical apparatus which enables to define the Hilbert space in which said computation occurs.

    Clearly, what happens at lower levels is directly influenced (causally acted upon) by what is happening at the higher level (of the classical apparatus). Thus the classical apparatus can be said to ’cause’ the particular Quantum interference at hand.

    Consciousness clearly acts classically (say by refusing to breathe). Thus consciousness modifies the classical apparatus (the set of all motor neurons, among other sets of neurons), and thus acts on Quantum Interference. And, clearly, reciprocally. Thus consciousness and Quantum are entangled. This means a ‘classical’ ‘explanation’ of consciousness is hopeless.

  16. Daniel Hawkley says:

    Thanks for this post and for your book The Big Picture; it’s the best tool I’ve found for bringing me back to what I want to think about.

    I’m reasonably confident that “consciousness” is the ability to identify:

    (question): what can we do to non-existing things that they cannot do to us?
    (prior credence): non-existing things don’t exist; (prior conclusion): ideas (identifying non-existing things) do exist; for example: false ideas identify non-existing things like: “empty space as nothing”;

    (in other words, prior credence): nothing cannot identify itself; therefore (without cause): everything (including Descartes) can identify nothing (predictions) and itself (observations); any other theory (theory B) must deny everything (including itself, in motion, as self-contradictory).

    (stated mathematically, as a foundational choice): we can prioritize zero (zero-centrism) or we can prioritize priority (as self-mutiplying). Model (decentralizing priority): identify points as imaginary numbers that, defying the zero-centric convention, produce the square-root of one (in any potential direction); then map the origin of any such “first” cube as requires the signature distances of the next “prioritized” fields: the square-roots of two and three.

    In summary (the rule of evidence): let the squaring function (as the ability to identify) differentiate between complete opposites: “before annihilation”.

    What we’ve done with “imaginary numbers” as “points” is diagonalization, disproving epistemic finitism; the truth (as priority) can be unbelievable: everything (including exclusive points) excludes nothing.

  17. James Cross says:

    Ultimately the “downward”, the “upward”, the particles, the fields are human representations in consciousness of an objective world.

    Does that make the problem easier?

  18. Ben Goren says:

    Nothing is gained, and much is lost, by abandoning such talk and simply saying “I don’t know the microstate of all your particles, but if I did your behavior would be determined, so there’s no such thing as choice.”

    This is where I would disagree, and vigorously.

    The first thing to gain is an acknowledgement that we are not special within the Universe, any more than the Earth was at its center before Copernicus. Rather, we’re merely at the center of our own self-centering maps of the Universe — which, of course, explains our illusions of specialness. Our mental lives really are souped-up versions of what happens in thermostats and airliner autopilots, like it or not.

    The rest of the gains should be obvious and are inevitable consequences of that realization.

    Nor is anything of value lost. We are very complex computational engines. If we can accept that computers and Rube Goldberg contraptions perform meaningful actions in deterministic (if perhaps unpredictable) ways, we should have no trouble accepting that we ourselves do the exact same types of calculus. The only thing lost is the notion that our calculations are of a fundamentally different nature — which they can’t possibly be.



  19. James Cross says:

    Regarding Tononi:

    I think Scott Aaronson pretty much demolishes IIT:

    “In my view, IIT fails to solve the Pretty-Hard Problem because it unavoidably predicts vast amounts of consciousness in physical systems that no sane person would regard as particularly “conscious” at all: indeed, systems that do nothing but apply a low-density parity-check code, or other simple transformations of their input data. Moreover, IIT predicts not merely that these systems are “slightly” conscious (which would be fine), but that they can be unboundedly more conscious than humans are.”

  20. Steve Ruis says:

    I am still lacking a good definition of “cause” but my two cents worth made me think of herd behavior, specifically in the form of schools of fish. Fish swim, but they don’t (can’t?) learn to swim in concert with other fish until a school is formed (interesting choice of terms). The emergent behaviors of synchronized swimming as a way of confusing predators, etc. seems to affect the way the individual fish swim. Whether the emergent property “causes” the individual fish to swim that way seems at least possible, while the individual behavior “causing” the emergent behavior seems less acceptable.

    In any case, I love the work you do for us laymen. I am still working my way through The Big Picture, a very meaty book that should not just be skimmed and I thank you for that (in addition to the cash money I put in your pocket when I purchased it!).

  21. Patrice Ayme says:

    Generally, by causation, people mean: when proposition A then proposition B. However, reality, even in pure logic is significantly more complex, on the face of it.
    What does ’cause’ mean in a logical system?
    A full logic is equipped with diverse types of axioms, and a so called ‘universe’, plus a notion of ‘truth’. In other words, the simplest full logical system is extremely complicated, and ‘true’ propositions are not just the result of a few axioms, but also of what the ‘universe’ is made of, plus a notion of truth (itself long a field of extensive research, to this day).
    Thus we see that, even in pure logic, ‘causation’ is, in general, not attributable to one cause, but to a causal web, so to speak.
    One should not expect that a full Quantum Physics and an attending theory of consciousness would be anything less complicated.

  22. Paul Pelosi says:

    The solution to the mystery of consciousness will alomost certainly lie in the phenomenon of emergence. Emergence is more than the sum of a collection of parts. Emergent properties are irreducible complexities. They cannot be reduced to component parts from whose simple or at least well known interactions causal relationships can be predicted per the laws of physics.

    I would be interested to hear Prof Carroll’s view of emergent phenomena. Is just saying ’emergence’ some kind of cop out? Is it a scientific variant of ‘God of the gaps’?, i.e., emergence did it.

    My own view, invoking reductio ad absurdum, is that no other explanation makes better sense, or any sense at all. Obviously consciousness is a product of large, complex brains. A human baby’s brain is a work in progress at birth and a baby is not conscious until about 18 months after birth. Thus size matters, and complexity is a function of size. An 18 month old babys brain is stlll a long way off adult size, so adult-size complexity is not necessary for consciousness. It may be the case that animals with brains similar in size to an 18 month old human baby are conscious and have a sense of self-experience.

    I think consciousness as an emergent phenomenon must simply be accepted. Finalising the standard model or mapping the human genome is to gain knowledge of components from events that are reducible to components. Since components cannot predict consciousness or consciousness be reducible to components, consciousness must forever remain a mystery, or at least undiscoverable by ‘normal’ science.

  23. James Cross says:

    Paul Pelosi

    “A baby’s brain is not conscious until about 18 months after birth”.

    Have you ever had a child?

    And what about bird brains.

  24. Daniel Weissman says:

    Sean, I disagree with the statement that “Nothing is gained… by abandoning such talk and simply saying ‘I don’t know the microstate of all your particles, but if I did your behavior would be determined, so there’s no such thing as choice.’”
    It was precisely this abandonment that convinced me that no sentient creature could ever “deserve” to suffer (because I didn’t find free-will-as-poetic-shorthand a good enough reason to assign the kind of moral responsibility that would justify, say, the death penalty). That’s an empirical fact, that I changed my mind and my actions. I know other people have had similar experiences. One could certainly argue that we’ve changed for the worse, but I don’t think you that. So that’s a gain.

    Separately: have the zombies folks ever explained why animals should have evolved not to be zombies?

  25. Coel says:

    Hi Ben,

    “The first thing to gain is an acknowledgement that we are not special within the Universe, […] which, of course, explains our illusions of specialness. Our mental lives really are souped-up versions of what happens in thermostats and airliner autopilots, like it or not.”

    I don’t think I’m at all special. I’m just a souped-up aircraft autopilot. I’m entirely comfortable with that and I like it that way. I don’t have any illusions of specialness.

    Having settled that, can I now be a compatibilist?

    You won’t understand compatibilism until you realise that it really is not a hankering after dualism, nor an attempt to make ourselves special in some way.