Mary revisited: The Brian problem

Generations of philosophers have been fascinated what has been termed the “Mary problem“. In essence, Mary is the worlds foremost expert on color vision and knows everything that there is to know about it. The catch is that she is (depending on the version) either color-blind or has never experienced color before. The question is (depending on the version) whether she is lacking something or whether she would gain new experiences/knowledge if she were to experience color. Supposedly, this is to show us interesting things about physicalism and qualia.

In reality, it only shows us how philosophy is fundamentally limited. The philosophical apperception of the world (as well as interactions among philosophers) is entirely language-based. Needless to say, this is an extremely impoverished way to conceive of reality. Language has all kinds of strange properties, including being inherently categorical. Its neural basis is poorly understood but known to be rather extraneous – most animals don’t have it, and even in the higher primates, most brain regions don’t involve language processing.

Yet, all of Mary’s knowledge is language-based. So yes, if she were to see a color, the part of her visual cortex that processes spectral information (assuming that part of her cortex was intact) would be activated and she would experience the corresponding color, for reasons that are still not well known.

Brian's brain

Brian’s brain

But the heart of the matter – and the inherent shortcomings of an understanding that is entirely language based (invisible to philosophers, as this is something shared by all of philosophy) can be illustrated by a new problem. So let’s add some color to the Mary problem. Here is the Mary problem reimagined: I call this the “Brian problem”:

Brian is the worlds foremost expert on all things sex. He has read every single paper that was ever published in sexology and he also has a keen grasp on the biological and physiological literature. Yet, he has never had sex. Now, Brian has a chance to have sex – would this give him an opportunity to learn anything that he doesn’t already know or have an experience that he didn’t already have? If so, why?

Put in this way, a sample of 100 undergrads were quite clear in their interpretation:

The Brian problem

This nicely illustrates the fundamental problem with language to assess the state of reality: Language has face validity to other people, because it is our mode of thinking, and probably evolved for reasons of social coordination. So arguments might seem compelling (particularly to unrepresentative subcommunities with a shared culture) that do not correspond to an apt description of reality in any other way.

If this is not clear yet: Imagine there being a rat who has never experienced anger but has read every paper on anger. Then you stimulate the ventromedial hypothalamus of this rat with optogenetic methods. Does the rat experience something new? If so, why?

There are really infinite variations of this. Say – for instance – Stephen has read every paper on LSD. He has an intricate understanding of how the drug works. He knows everything there is to know about serotonin receptors and their interactions with ligands. He even understands mTOR, GCaMP and knows everything there is to know about phosphorylation as well as methylation (although that might not be directly relevant). Yet, he has never taken LSD. Now, Stephen is about to take some LSD. Will he experience something that he has not experienced before? Will he learn something? Is this really that hard to understand if one has a lot of prior exposure to philosophical thought?

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6 Responses to Mary revisited: The Brian problem

  1. Peter Smith says:

    That seems to me to be the same problem. Whether it is colour, sexual experience, taste, etc, these are all problems of the qualia. We experience the qualia but cannot accurately convey the experience of qualia as knowledge.

    My description of the experience of qualia only has meaning to you in so far as it invokes memories of your own experience of the same qualia. If you had not experienced similar qualia my description would not convey anything useful to you.

    The problem with the Mary/Monochrome Room thought experiment lies in the conclusion. The conclusion says that on leaving the room and seeing a red rose she now ‘knows’ for the first time what it is like to see red.

    But she hasn’t acquired new knowledge, she has acquired a new memory of a new experience and that is not the same thing as knowledge.

    It seems to me that we have two kinds of memory. One kind of memory is semantic. It is exact, can be clearly reproduced and conveyed to others. I can precisely recall a Shakespearean sonnet and quote it to you. This we call knowledge.

    Then we have the memory of the experience of qualia. The memory itself is veiled. I cannot recall with the same vividness the original experience of the qualia. But if I experience the qualia anew I recognise it as being similar to earlier experiences. Because I cannot recall the experience in the same exact way I recall the memory of a sonnet I cannot convey the experience to others and so it falls outside the realm of knowledge.

    I think it has all to do with emotion. Tim Noakes surprised the sporting world by proposing that we do not directly experience fatigue(the Central Governor Theory). Instead fatigue is conveyed to the conscious mind as an emotion. Endurance runners know that the principal problem they must overcome is their own emotional reaction to testing conditions. I think this applies to all the qualia. They are presented to the mind as emotions which serve to motivate action. Thus we experience the emotional or motivating force of the qualia. Therefore we can only describe how it motivates us and cannot describe the original qualia, since that is never presented to our mind.

    Once we see it as a problem of the emotions the problem of Mary in the Monochrome Room goes away.

  2. John Kubie says:

    I largely agree with Peter Smith. As I see it, a problem with “The Mary Problem” and many philosophical examples involving consciousness and subjective experience is they use examples from the visual system. Visual qualia perhaps unique in evoking little affective response (emotional response). As a result, there is no hint of a link to motivation or action. If we think of smell or taste or somatic sensation, almost all stimuli are pleasant or unpleasant and evoke specific responses. Compare the qualia of the taste of fine wine with the qualia of red.
    The problem of focusing on visual examples as generic perception is not limited to philosophers; many neuroscientists fall into the same trap.

  3. Anonymous says:

    I’ve always understood Mary the color scientist as a story to expose intuitions about experience – particularly, that subjective experiences are categorically distinct from physical facts. So I’m not sure what surveying undergrads adds, besides affirming that the story successfully draws out the intuitions that its creator intended. (The new story is effectively identical: “P knows every physical fact about X but has not experienced X itself. If P experiences X tomorrow, does P learn anything?”). If your goal was to address a shortcoming of philosophy’s “language-based” approach, surely you haven’t succeeded by tallying undergraduates’ equally language-based responses.

    I think you should be a little more cautious about pejoratively characterizing philosophy as language-based and contrasting it with science as such. Yes, sometimes (particularly in perception) there are debates which seem reducible to mere labeling or categorization problems. But typically, the objects of philosophical investigation are substantive: while discourse is language-based, language is usually understood as representing real phenomena as being a specific way.

    Furthermore, if being language-based in this sense is a problem for philosophy, then it is also a problem for science. While scientific inference ostensibly distinguishes itself by employing empirical observations, it’s not clear to me that the way in which the inference procedure itself is not language-based in the same way was philosophical arguments.

    As far as I can tell, most scientists consider Karl Popper to be the main protagonist in the development of scientific inference. Popperian falsificationism essentially construes scientific inference as iteratively refining theories by using modus tollens to refute inductive conjectures with empirical violations. But the propositions in a Popperian scheme are sentential – in other words, language-based. Even if we relax some Popperian constraints and allow purely mathematical theories, it will still be essentially language-based in the same sense (just in a formal language).

  4. Anonymous says:

    hanks for taking the time to thoroughly consider, but it’s not clear to me what data you’d find helpful here. Did you mean:

    - data on the philosophical attitudes of scientists (eg, are they Popperians?)

    No good data exists here afaik. Someone should collect it.

    - data on substantive philosophical debates.

    Examples: Scientific anti/realism, modal realism, metaethical anti/realism, motivational internal/externalism … loads of examples where argument is over the nature/existence of the object denoted by a word, not the correctness of the denotation.

    - data on whether science is as “language based” as philosophy

    Not sure what such data would look like, but you don’t really need it. This is just formal logic 101: what’s the difference between inductive inference and deductive inference, why is the former not logically valid. Logic is “language based”; justifying scientific inference from data to general principles relies on formal logic; science is language based.Data by itself is not a scientific theory, and using data to justify an inference to a theoretical claim is a language based enterprise. This is pretty trivial.

    - data on what Mary the color scientist does

    You could start at the SEP page. I don’t disagree that there is something unsatisfying and overly semantic here; the success of the argument obviously hinges on whether you think experiences count as knowledge, both of which are notorious for causing semantic confusion. The story about Mary is meant to prime certain intuitions about experience and knowledge so that you agree with the claim that experiences count as knowledge. Looks like it worked on your undergrads; good manipulation check. What now?

    Fundamentally, I have two beefs.

    First is that your survey of undergrads tells us basically nothing about the Mary cover story besides its success at priming certain intuitions. It might be interesting to a linguist, but it doesn’t do what you seem to think it does. It’s a little surprising that you seem to think adding data magically demonstrates something substantial. And I’m not even a big fan of the Mary story!

    Second is that you’re using one particular instance of a semantic debate to draw an inaccurate caricature of a large and diverse field. What if I used some of Simone Schnall’s work to indict all of psychology and neuroscience as frivolous and careless, producing arbitrary, uninteresting theories that failed to replicate? That’d be ludicrous, even if it’s certainly true of *some* psychology and neuroscience.

    I don’t think “Data” really replies to either of these concerns.

  5. The knowledge argument is done:,_A_Philosopher%27s_Whore_of_Color_and_Her_Knowledge_Problem

    Basically, yes she does learn something new … but it’s information that did not previously exist in the universe. Given sufficient tech, she might well have known exactly what synapses and neurons would grow in her brain upon experiencing color. But that would not make them grow any more than understanding diabetes will let the sufferer go without insulin.

    It only happens, and the knowledge comes to be … AS PHYSICAL CHANGE IN HER BRAIN … upon her exposure to color.

    The “Mary” argument thus turns on its head and becomes a simple and clear demonstration of physicalism.

    On antiphilosopher there’s a similar deconstruction regarding flying philosophical vermin.

    – TWZ

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