Frank Jackson is famous for the following argument:
Mary the color scientist knows all the physical facts about color, including every physical fact about the experience of color in other people, from the behavior a particular color is likely to elicit to the specific sequence of neurological firings that register that a color has been seen. However, she has been confined from birth to a room that is black and white, and is only allowed to observe the outside world through a black and white monitor. When she is allowed to leave the room, it must be admitted that she learns something about the color red the first time she sees it — specifically, she learns what it is like to see that color.
Pretty simple, right? The argument is usually put like this:
- Before exiting the room, Mary knew everything physical about the phenomenon of seeing the color red.
- After leaving the room, Mary gains new information about seeing the color red, namely, the information concerning what it is like to see that color.
- Accordingly, there are some truths about seeing color that are not physical.
- Therefore, physicalism as a theory of phenomenal properties is false.
This argument is sometimes said to be a definitive proof for the existence of things called “qualia”. And because the thought experiment shows that qualia are not physical things, physicalism is false because it claims that what we call mental things are really just physical things. Right? Well, not really. The only thing this argument knocks down is a giant strawman of physicalism. Here are my thoughts:
- On first blush, the whole thing is dreadfully implausible. Accordingly, it becomes difficult to extrapolate from science fiction to what’s actually going on in someone’s mind when they perceive a red object. Physicalism’s explanation of seeing the color red should be based on studying normal people looking at red objects under normal lighting conditions (similar to the lighting conditions and medium composition in which we evolved for millions of years: day and night). If Mary had been confined to a black and white room for the entirety of her life, her visual cortex would be wired (“fire together, wire together”) completely differently than a normal person, and may not even be capable of discriminating colored objects. Moreover, anyone who spends their entire life in a single room is going to have some serious neural abnormalities compared to the average human adult. If Mary stepped outside of her room into the real world, I’m not sure she would learn anything about colored objects since her brain had never been exposed to the light reflecting off colored objects, and accordingly would have not been properly configured for discriminating colored objects in the way a normal human adult does.
- Jackson’s physicalism is a strawman because he is assuming that physicalists are internalists just like him. He says that a physical story about seeing color would talk about the “neurological firings that register that a color has been seen”. Notice that word “register”. It sounds so innocuous, doesn’t it? This way of talking is actually an inheritance from John Locke’s empiricism. Locke thought that the purpose of consciousness was to copy experience onto the “white paper” of the mind, which was devoid of ideas at birth. To register something is to record it somewhere. To record is to copy. When Jackson talks about the brain “registering” the color, he really means copying the properties onto a recording format, which is then read off or “interpreted” by the Inference-machine.
- In other words, Jackson’s strawman of a physicalist story is the famous “Glassy essence” or “Mirror of nature” theory that Richard Rorty always talked about. It can also be called the Myth of the Given because it is implicitly assumed that the perceptual stimulus for animal perception is an objective (i.e. valueless) world which is given as such to the organism. In a way, this is trivially true. Of course an objective world is given to organisms. But the objective world is not stimulating. In other words, animal brains did not evolve to be responsive to the properties theorized in physical science such as wavelengths or protons. They evolved so as to be responsive to the ecological level of reality. In Gibsonian terms, we can say that animals evolved in a niche such that the information for the specification of affordances (values) is invariant over retinal transformation. Therefore, the stimulus information discriminated by animals is immediately meaningful for the animal insofar how it perturbs the system is familiar to its nervous system in virtue of the history of interaction with these very values. Affordances are really just possibilities. We perceive the world in terms of the different possibilities afforded by the environment. And as Matthew Ratcliffe has pointed out, these possibilities should not just be seen in terms of bodily possibilities, but also event possibilities e.g. seeing manifold possibilities for social interaction, for how objects might behave in the world, etc.
- Therefore, we must reconceptualize what it means for Mary to “gain new information” when she steps into the colored world. First and foremost, she would gain possibilities for discrimination, not registration. It wouldn’t be that there was now a new “quale” or phenomenal object floating around inside a conscious space, being associated with other quales. This is ridiculous. When the brain perceives a red firetruck, it doesn’t just “copy” or “register” the objective physical properties onto an internal film for later recovery. Upon seeing a red firetruck coming right at you, the very elementary subcomponents of the stimulus are valenced in terms of “Oh shit, get out of the way!”. It is patently ridiculous that an organism would have evolved a object-registering capacity before a threat-discrimination capacity. This fact explodes the Myth of the Given because it turns out that what stimulates animals are meanings, which is to say possibilities.
- So, now we can see a tacit premise in Jackson’s argument: (4a) Physicalism is committed to the Myth of the Given. However, since physicalism is not necessarily committed to the Mirror-hypothesis, Jackson’s argument only defeats a weak strawman of physicalist explanations of color perception. Because ecological theory holds that “information for perception” is relative to the individual possibility space of the perceptual agent, Mary could definitely not have learned about “all there is to know” about perception while trapped inside a black and white room, since she had never explored her own possibilities for discrimination in the real world. But why this should “prove” physicalism to be false is beyond me. Of course Mary is learning “something”. But we should not take this too literally, for possibility-spaces, valences, and meanings are not “things” in the way a stump of wood is a thing. It is a thing only when speaking metaphorically. The Myth of the Given, where given ideas are “quales” manipulated in cognitive space by the brain, is itself a metaphor for understanding perception,structured by our everyday experiences with individuated (possibly withdrawn?) objects that can be manipulated in physical space, just like ideas.