Aliens versus Materialists (Part I)

The following is a science fiction about consciousness in which I’ve twisted a few counterfactual knobs to make things tough for the materialist. In this attempted reductio, I assume physicalism is the case, and generate a putatively serious objection. It is the only line of thought that has recently given me serious worries as a neurophile, so I am curious what others think.

Imagine there exists an alien species that not only lacks concepts about subjective experience, but is altogether devoid of subjective experience. Perhaps they are insensate proposition-crunchers or implement an extremely plastic lookup table. They have come to Earth to study the brains of cats, a species that (unlike them) is conscious but (like them) has no conception of consciousness.

 Note I realize this may ultimately be an incoherent scenario, but let’s go with it to examine the implications, if any, for the materialist. After all, if materialism can escape unscathed from a story custom-made to favor antimaterialism, that will bode poorly for many weaker species of antimaterialist arguments.

 The aliens take a purely scientific approach to cats, using only neural and behavioral data (including “wide” facts about the cats’ environment) as the basis for their theories. They discover many higher-level properties of nervous systems by carefully studying phenomena that we associate with consciousness: anesthesia, dreaming, hallucinations (e.g., phantom limbs), perceptual illusions (e.g., binocular rivalry), and more general sensory and perceptual processes (e.g., sensory thresholds and attention).  

 Their research reveals two distinct modes of neural processing, a conspicuous division between (what we call) conscious and unconscious processes.  The aliens refer to them as ‘smonscious’ and ‘unsmonscious’ processing modes, which they proceed to study exhaustively. Smonscious processes involve the neural construction of a low-capacity, highly integrated multimodal sensory representation of what is presently happening nearby. The second, unsmonscious, processing mode is extremely high capacity but lacks coherence and dense intercommunication among its constituent representations, though it includes a massive cortical memory store.

 They also find that the two processes have quite different functional consequences within the ecology of the nervous system: there are clear differences in their interactions with episodic memory, decision making, attention, and working memory. Disrupting smonscious processing is devastating for any cat, so the aliens are never tempted to suggest that smonsciousness is an epiphenomenon.

 Even though the aliens enjoy no conscious experiences, they develop their neuropsychological theory to the point where they can produce a thick phenomenological portrait of the cat’s world in real time. ‘Right now he is smonscious of the smell of a mouse nearby, but not that the dog barked, because he is not attending to auditory inputs.’ The contents of this polymodal ‘movie’ perfectly describe the conscious perceptual experiences of the cat.

 In sum, the signatures of conscious versus unconscious neural processes are written starkly into the objective computational contours of the CNS. Metaphysically speaking, since experiences are brain processes of a certain sort, and the aliens have discovered said brain processes, they have ipso facto discovered and characterized conscious brains in objective terms.  There is no additional property out there remaining for the aliens to discover, no new ingredient that must be added to their story to make it complete. Far from being only available “subjectively,” subjectivity itself is an objective feature of the brain that will be discovered by anyone that takes a dispassionate look

So far, the materialist in me is very happy. In Part II, this takes a bit of a U-turn.


  1. Eric: “Imagine there exists an alien species that not only lacks concepts about subjective experience, but is altogether devoid of subjective experience. Perhaps they are insensate proposition-crunchers or implement an extremely plastic lookup table. They have come to Earth to study the brains of cats, a species that (unlike them) is conscious but (like them) has no conception of consciousness …… I realize this may ultimately be an incoherent scenario …”

    For what I consider a solid reason, I think this is an incoherent scenario, but I look forward to your argument in Part III.

  2. Eric Thomson

    It may not be possible for a species to do science unless it is conscious, but I’m not going to focus on that as a weakness of this argument. As I mentioned, if a materialist can respond to this worst-case scenario convincingly, then a whole family of much weaker arguments from the antimaterialists falls. What is most important is the conceptual point.

    At any rate, I’d be curious about your reason for thinking this is incoherent. I think it is probably not literally incoherent as much as far fetched. But I don’t feel strongly either way on this one. I don’t think much really rides on this in my arguments, frankly.

  3. Eric Thomson

    Arnold in general those that really can’t enter the counterfactual scenario I’ve painted without feelings of incredulity, I think they should think of it not as unconscious alien scientists, but simply a community of humans who are radical behaviorists by nature, who do not have the concept of consciousness, who decide to study brains.

    I’m curious what people think of Part II as it presents what seems a serious push against materialism. I do have a response of my own, but it is frankly less than satisfying. I was hoping someone would have a quick/easy/obvious response to Part II.

    The most obvious, or at least common right now, response would be to go some kind of phenomenal concepts strategy where the phenomenal conception of consciousness cannot be acquired without having experiences yourself. I would prefer to avoid this route, frankly, but perhaps it is the best we can do.

  4. Richard Brown

    Hi Eric, have you read Block’s paper ‘the harder problem of consciousness’? Also interesting is Geoff Lee’s forthcoming paper:

    For myself I don’t see why you want to avoid the idea that you need to have the experience in order to acquire the concept. I tend to like this idea (it is just classic empiricism). What do you have against it?
    There are some philosophers whose views might commit them to the claim that the aliens can acquire the concept without ever having the experience. Some, for instance, might take the causal theory of reference seriously and endorse something like the idea of ‘reference borrowing’. Roughly the idea is that I can refer to Socrates with ‘Socrates’ even though I have never seen Socrates. I can do so because the semantic type ‘Socrates’ has a causal-historical connection to the actual Socrates (and not Aristotle). On this kind of view (maybe held by Derek Ball here: ) perhaps the Aliens do acquire the concept. 
  5. Eric Thomson

    Thanks Richard that is very helpful. I hadn’t yet read any of the papers you mentioned. I will check them out and try to incorporate the helpful bits into my Part III.

    You asked:
    ” I don’t see why you want to avoid the idea that you need to have the
    experience in order to acquire the concept. I tend to like this idea (it
    is just classic empiricism). What do you have against it?”
    I don’t like it because it makes consciousness anomalous. I don’t have to be a plant to acquire the concept of photosynthesis, for instance. Since (by hypothesis) consciousness as yet another complex evolved biological property, so I don’t like any theory in which there is some special epistemology erected for it. I find it unsatisfying.

    But perhaps I shouldn’t be so inflexible. After all, some biological processes underlie our ability to gain knowledge, acquire concepts, etc. Others do not. Why wouldn’t we expect the former to have epistemological implications that don’t apply to plants and such? Why would that be unsatisfying or strange? It might be like acting unsatisfied that studying photosynthesis reveals some limitations on how plants convert sunlight into energy.

    The causal theory route is interesting. While under materialism the aliens acquire the concept with the right reference (the smonscious processing stream), they don’t ever get the sense right. When grandma talks of an experience of a pain in her toe, she is making sense even though its reference is utterly opaque to her. This, of course, is the crux: while there is this logical possibility of two concepts/one thing, how reasonable or likely is it to be what is actually going on, versus a kind of pacifier to make materialists feel good?

    I will read Derek Ball’s paper, which seems to go after this issue directly.

  6. This seems to be another ingenious way to decouple our epistemic intuitions from our phenomenal a la Jackson’s Mary, but I’m not convinced it is. You frame the question as the aliens lacking any ‘subjective experience,’ having no concepts of consciousness, though having complete knowledge of the material systems that make consciousness possible. In a sense, you define the dilemma into the thought experiment by taking this first step: you assume, 1) that consciousness is the result of brain processes; 2) that the aliens know everything there is to know about brain processes; and 3) that they know nothing about consciousness. Plainly these claims are inconsistent. Either their knowledge is incomplete, or consciousness is not the result of brain processes, or they do know about consciousness.

    Is there something I’m missing Eric?

  7. Eric Thomson

    Scott you framed it nicely. The point is that it is meant to be a reductio of materialism, so assuming materialism is true, you end up with these aliens that don’t even know about the most essential aspect of consciousness; hence the reductio.

    I wouldn’t say I’m defining the problem into existence, as much as creating a scenario that highlights a problem that many others have highlighted, but in a way I find much harder to address because it closes some of the usual loopholes materialists use to escape. Or at least some of the loopholes I have used.

  8. I appreciate what your saying. The parable does serve to highlight the always perplexing empirical invisibility of consciousness. The materialist wants to convince the aliens they are missing something, but when they tally up all their respective facts, they can find no discrepencies.

    But this is just a compelling narrative way to say that the materialist hasn’t yet solved the Hard Problem, to illustrate how they could, *possibly,* come to know all the facts about the brain and still be clueless about conscious experience.

    Otherwise, I don’t see how the reductio works in this case. In reductios, the inconsistency is implicit, invisible, and its only the explicit inconsistency of your conclusion that allows you to see your premises are problematic. In this case, the inconsistency is explicit to begin with. By saying the aliens don’t have knowledge of conscious experience and that they know everything there is to know about neurophysiology you are literally saying, ‘Materialism is false’ from the outset.

    I think you need to goose the aliens somehow, give them a twist, to push this story into Mary territory, where it really starts making knots of our intuitions.

  9. Eric Thomson

    Scott: I will be pushing it in weird directions in Part III (e.g., how would the aliens react if they made themselves smonscious?).

    Note, though, I don’t think it quite builds in that materialism is false. The most common response is that while they are conceptually telling an incomplete story, at a metaphysical level they have left nothing out.  E.g., while at a conceptual/semantic level ‘subjective experience of red’ doesn’t mean ‘smonscious brain state X’, that doesn’t imply that subjective experiences are not, in fact, identical to smonscious brain state X. This is analagous to the fact that ‘water’ turned out to be ‘H20’ even though those two terms have different meaning. This is the ‘two concepts/one property’ strategy I attacked in Part II when playing the part of antimaterialist.

    This is the most promising response I know of for the materialist, as it allows the aliens to not conceive of consciousness even though materialism is actually true. The theory of ‘phenomenal concepts’ is one branch in this family of responses (though antimaterialists likely need phenomenal concepts too, as Derek Ball’s paper cited above by Richard Brown argues, so in a sense this whole ‘phenomenal concepts’ stuff might be metaphysically neutral).

  10. I’m not quite convinced by your ‘quite,’ Eric! And I tend to be pessimistic about semantic assaults on any of these problems.

    But ‘weird directions’ is what this is all about (it’s the cornerstone of my approach!). I look forward to the next chapter! I have a little spin of my own on your story gestating, which I’ll lay on you when I have it roughed out.

    In the meantime I’m curious to hear what you make of the Mary re-interpretation I came up with in my recent review of Tononi’s Phi:

  11. Eric Thomson

    “I tend to be pessimistic about semantic assaults on any of these problems.”

    This is smart, in my opinion. I looked over your post very quickly, and think it is reasonable (though again, I read it very quickly), and am surprised by how much influence Mary has had in philosophy. This “alien” scenario closes some of the obvious loopholes that Mary leaves open (e.g., she already has concepts about experience, and even has visual experiences, and has concepts about other people’s color experiences even though she lacks the experiences herself).

    I like Tononi’s work, and Edelman a lot (my personal view is very close to theirs), and you can think of the ‘smonscious’ processing stream of the aliens in terms of Tononi/Edelman’s theories and that would work out fine.  I was purposely quite noncommittal about the actual neural basis the aliens discovered, so you can plug in your favorite theory without mutilating my arguments.

  12. I actually find these kinds of parables interesting from a symptomatic (or second-order) perspective: so for me, what makes them interesting isn’t how they argue or how they can be argued (which are first-order semantic issues) but what they say about our ‘intuitions’ – viz., the putative cognitive mechanisms they trigger. So for me, what makes Mary exemplary is the clear way it pulls the phenomenal out from the cognitive aegis of semantic/epistemic cognition, and thus displays the *neglect* that characterizes the latter. Why should a deepening of Mary’s informatic relationship with her environment not automatically be recognized as a deepening of her epistemic relationship? It really highlights something peculiar about human cognition. The fact that various theorists can game the ambiguities this way and that to provide first-order analyses should come as no surprise, given human theoretical incompetence (outside the sciences at least).

    The thing with Tononi, vis a vis your parable, is that a given phenomenal experience simply IS a given ‘Q-space.’ I’m not sure how his account allows you the wiggle room to distinguish ‘conscious’ from ‘smonscious.’

  13. Chalk me up as another who is skeptical about an armchair solution to the debate about physicalism/materialism.

    On the integrated information approach to consciousness: How can we distinguish the phi of a Google server center from the phi of any living person?

  14. Eric Thomson

    The thing with Tononi, vis a vis your parable, is that a given
    phenomenal experience simply IS a given ‘Q-space.’ I’m not sure how his
    account allows you the wiggle room to distinguish ‘conscious’ from

    That’s precisely the issue. For the materialist, to be smonscious (in Q-space Q2 or whatever) is to be conscious. This is the premise from which the reductio in Part II follows!

    Let’s apply it in this case.

    Say the aliens discover, from studies of the brain, a Q-space and its biological importance (e.g., a subset of the neural state space with certain information-integration properties in the cat). This is still conceptually different from knowing that there is something it is like to instantiate such a space. They just have this mathematical theory with a certain structure, and it applies to brains of cats extremely well. Similarly, they they may have a mathematical theory with a certain structure that might apply to planetary orbits. In neither case are they tempted to say that there is something it is like to instantiate this structure, that there is experience there. In each case there is a complex process that follows certain rules that they have exhaustively given.

  15. Eric Thomson

    Arnold that is my concern with the specific measure Tononi advocates too. It is too promiscuous. Perhaps it should be treated as a necessary, but not sufficient, condition for consciousness. On other matters, Edelman (and Tononi) seem on the right track.

    I am skeptical of armchair solutions too, but not of their usefulness for posing problems. Too many materialists dismiss thought experiments, when the scenarios are just making a conceptual point that will eventually need to be addressed (or at least dismissesd rationally rather than with a shrug).

    But I too am suspicious of any philosopher who thinks they have a knock-down argument against something that science makes me think is reasonable. E.g., Fodor, Chalmers, etc.. That’s why I posed my argument in Part II in inductive terms; not a knock-down argument, but something that the materialists should be concerned about when they get down to the level of what is reasonable, in the real world of inductive rationality. That’s where they, of all people, live.

  16. Let me pose a couple questions, just to be sure I’m not off my rocker here…

    Is it fair to assume that the aliens, despite having no awareness of conscious experience, nevertheless possess neurally instantiated representations of their environments? And that likewise, they possess a language roughly comparable to human language (only lacking all concepts relating to conscious experience)?

  17. Hi Eric. I want to say I posted a ‘response’ to your thought experiment, but really it just takes your premise as an occasion to think through some of the crazier thoughts that have been preoccupying my subpersonal brain as of late. It came out of an attempt to show the difficulty of maintaining a principled distinction between conscious and smonscious concepts…

    Either way, I would love to hear your take.

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