Hidden Qualia


In this paper, I propose that those who reject higher-order theories of consciousness should not rule out the possibility of having conscious experiences that they cannot introspect. I begin by offering four arguments that such non-introspectible conscious experiences are possible. Next, I offer two arguments for thinking that we actually have such experiences. According to the first argument, it is unlikely that evolution would have furnished us with a faculty of introspection that worked flawlessly. According to the second argument, there are many plausible potential sources of non-introspectible experiences. Given that all of these sources are at least somewhat plausible, it is fairly probable that we have some kind or other. Finally, I consider whether we might be justified in believing that we can introspect all of our conscious experiences if in fact we can. I show that current approaches to justifying belief in epiphenomenal qualia do not carry over. The upshot of these arguments is that we should be less certain that we really know what it feels like to be us. There may be much more to our experiences than we are aware of.

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Fig. 1


  1. 1.

    The first assumption is rejected by those physicalists who deny that there is any deep sense in which our experiences have phenomenal characters. They might hold, for instance, that we attribute phenomenal characters to our mental states as part of an over-simplified model of cognition (Graziano 2013), and that there is nothing in reality that fits the model (Dennett 1988). The second assumption is rejected by those physicalists who deny that the phenomenal characters of our mental states are independent of our beliefs about them, as in the higher-order thought theories developed by Rosenthal (1990) and Carruthers (2003).

  2. 2.

    No causal relation is necessary: a pre-established harmony between our introspective faculties and our qualia would be sufficient for those qualia not to be hidden as long as we would still be poised to form beliefs about them as a result of introspection. For this reason, epiphenomenal qualia are not automatically hidden.

  3. 3.

    Carruthers (1989) talks about ‘unconscious experiences’, which are similar to what I am calling ‘hidden qualia’, but he claims they make no contribution to what it is like to be us. For that reason, hidden qualia need not be involved in unconscious experiences.

  4. 4.

    Eric Schwitzgebel (2011) provides a range of examples in which introspection produces uncertainty or pervasive disagreement about the nature of our experiences.

  5. 5.

    Papineau (2002) gives a version of this argument in defense of the possibility of hidden qualia.

  6. 6.

    Even leaving aside higher-order theorists, not everyone agrees that qualia and beliefs about qualia are distinct. One strain of the phenomenal concept strategy (developed, for instance, in McLaughlin 1999 and Chalmers 2003) holds that qualia are constituents in some of our beliefs about them. Nevertheless, we might still use Hume’s dictum to demonstrate the possibility of hidden qualia so long as the relevant beliefs contain constituents apart from the quale, that are themselves intrinsically typed and distinct from the quale. It is exceedingly plausible that beliefs have a part that goes beyond whatever qualia they are about, and that Hume’s dictum will tell us that at the very least, qualia could exist while whatever else would be required for a further belief does not.

  7. 7.

    It is conceivable that a flawless faculty of introspection might have resulted from a neural reorganization that did not impose any metabolic cost. (Thanks to an anonymous reviewer for this suggestion.) Such a reorganization would not need to earn its keep. Nevertheless, the reorganization would not spread throughout the population unless it were specifically selected for.

  8. 8.

    Although some forms of sensory information received on one side of the body are first directed to the contralateral hemisphere, each hemisphere also receives information from the ipsilateral side of the body across the corpus callosum.

  9. 9.

    This is because we cannot know whether a given direct phenomenal belief is a direct phenomenal belief. Mathematical beliefs are often incorrigible, but that doesn’t justify them all by itself.

  10. 10.

    Here is Chalmers on the incorrigibility of disbelief: “Incorrigibility theses are also sometimes articulated in a negative form, requiring that a subject cannot be mistaken in their belief that they are not having a given sort of experience. No direct phenomenal belief is a negative phenomenal belief, so the current framework does not support this thesis, and I think the thesis is false in general.” (2003, 245)


  1. Block, Ned. 1995. On a confusion about a function of consciousness. Behavioral and Brain Sciences 18(2): 227–247.

    Article  Google Scholar 

  2. Block, Ned. 2007. Consciousness, accessibility, and the mesh between psychology and neuroscience. Behavioral and Brain Sciences 30(5): 481–499.

    Google Scholar 

  3. Block, Ned. 2008. Consciousness and cognitive access. Proceedings of the Aristotelian Society 108(3): 289–317.

    Article  Google Scholar 

  4. Byrne, Alex. 1997. Some like it HOT: consciousness and higher-order thoughts. Philosophical Studies 2(2): 103–29.

    Article  Google Scholar 

  5. Carruthers, Peter. 1989. Brute experience. Journal of Philosophy 86: 258–269.

    Article  Google Scholar 

  6. Carruthers, Peter. 2003. Phenomenal consciousness: a naturalistic theory. Cambridge: Cambridge University Press.

    Google Scholar 

  7. Chalmers, David. 1997. The conscious mind: in search of a fundamental theory. London: Oxford University Press.

    Google Scholar 

  8. Chalmers, David. 2003. The content and epistemology of phenomenal belief. In Consciousness: new philosophical perspectives, eds. Q. Smith and A. Jokic. London, Oxford University Press.

  9. Dennett, Daniel. 1988. Quining qualia. In Consciousness in modern science, eds. A. Marcel and E. Bisiach. London, Oxford University Press.

  10. Feldman, Richard. 2004. The justification of introspective belief. In Evidentialism: essays in epistemology, eds. Earl Conee and Richard Feldman. London, Oxford University Press.

  11. Fumerton, Richard. 1995. Metaepistemology and skepticism: Rowman & Littlefield Publishers.

  12. Fumerton, Richard. 2005. Speckled hens and objects of acquaintance. Philosophical Perspectives 19(1): 121–138.

    Article  Google Scholar 

  13. Graziano, Michael. 2013. Consciousness and the social brain. London: Oxford University Press.

    Google Scholar 

  14. Hill, Christopher, and Brian McLaughlin. 1999. There are fewer things in reality than are dreamt of in Chalmers’s philosophy. Philosophy and Phenomenological Research 59(2): 445–454.

    Article  Google Scholar 

  15. Moore, Dwayne. 2012. On Robinson’s response to the self-stultifying objection. Review of Philosophy and Psychology 3(4): 627–641.

    Article  Google Scholar 

  16. Papineau, David. 2002. Thinking About Consciousness. London: Oxford University Press.

    Google Scholar 

  17. Poston, Ted. 2007. Acquaintance and the problem of the speckled hen. Philosophical Studies 132(2): 331–346.

    Article  Google Scholar 

  18. Prinz, Jesse. 2000. A neurofunctional theory of visual consciousness. Consciousness and Cognition 9(2): 243–259.

    Article  Google Scholar 

  19. Puccetti, Roland. 1981. The case for mental duality: evidence from split-brain data and other considerations. Behavioral and Brain Sciences 4: 93–99.

    Article  Google Scholar 

  20. Rosenthal, David. 1990. A theory of consciousness: Zentrum für Interdisziplinäre Forschung.

  21. Schwitzgebel, Eric. 2007. Do you have constant tactile experience of your feet in your shoes?: or is experience limited to what’s in attention? Journal of Consciousness Studies 14(3): 5–35.

  22. Schwitzgebel, Eric. 2011. Perplexities of consciousness. Cambridge: MIT Press.

  23. Sosa, Ernest. 2003. Privileged access. In Consciousness: new philosophical perspectives, eds. Quentin Smith and Aleksandar Jokic. Cambridge, Cambridge University Press.

  24. Tye, Michael. 1995. Ten problems of consciousness: a representational theory of the phenomenal mind. Cambridge: MIT Press.

  25. Wilson, Jessica. 2010. What is Hume’s dictum, and why believe it? Philosophy and Phenomenological Research 80(3): 595–637.

    Article  Google Scholar 

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Thanks to Paul Audi, Jerry Cederblom, David Chalmers, Troy Cross, Laura Grams, Halla Kim, Andrew Newman, an audience at the University of Nebraska Omaha, and several anonymous referees for comments and discussion of this paper. A special thanks to William Melanson for extensive and helpful criticisms of my arguments.

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Correspondence to Derek Shiller.

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Shiller, D. Hidden Qualia. Rev.Phil.Psych. 8, 165–180 (2017). https://doi.org/10.1007/s13164-015-0297-5

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  • Conscious Experience
  • Phenomenal Character
  • Phenomenal Concept
  • Phenomenal Concept Strategy
  • Cognitive Sophistication