Often when I mention that I’m a functionalist in terms of the mind, someone references the Stanford Encyclopedia entry on functionalism. Strange to say, but I’ve never gone through that entire entry. This week I poked around a little in it, mostly in the objections section. Most of the objections either strike me as more a consequence than a problem, or seem strained and contrived.
But the last objection the entry covers, the problem of qualia, I’ll acknowledge is different. I can understand why people see it as a problem.
From section 5.5 of the article:
Functionalist theories of all varieties — whether analytic or empirical, FSIT or functional specification — attempt to characterize mental states exclusively in relational, specifically causal, terms. A common and persistent objection, however, is that no such characterizations can capture the phenomenal character, or “qualia”, of experiential states such as perceptions, emotions, and bodily sensations, since they would leave out certain essential properties of those experiential states, namely, “what it’s like” (Nagel 1974) to have them.
This is, of course, another description of David Chalmers’ hard problem of consciousness or Joseph Levine’s explanatory gap. Philip Goff often characterizes this as a divide between quantities and qualities. Science can handle quantities but not qualities. And this is by design, since Galileo excluded qualities to make science work. Science can’t deal with the problem of consciousness, Goff says, because its foundations excludes the subject matter. All of which resonates with this objection to functionalism.
The issue, I think, is failing to think about what perceptual qualities actually are. Many philosophers seem to take them as something irreducible and fundamental. To ask what they might be or do seems to violate some norm. Even illusionists seem to buy into this, at least up until they dismiss qualia. But I think it’s important to ask Daniel Dennett’s hard question: “And then what happens?” Put another way, what causes qualia, and what do they cause? What is their role in the causal chain?
We can begin to get at this by looking at what happens when the experience of that quality is missing. Consider the perennial example of color. A person with red-green color blindness typically can’t see the “74” in the image below, instead usually seeing “21”. A completely color blind person won’t see any numbers at all.
So, absence of some or all of the normal experience of color comes with functional costs. In this example, an inability to discriminate between the reddish and greenish circles. In the world, it means less able to discriminate between different types of objects, such as between flowers, or what traffic lights are indicating. For a monkey in the wild, it might mean ability to recognize ripe fruit, which tends to be yellower or redder. This is often thought to be why primates have better color discrimination than most mammals.
So the experience of color seems to fulfill a functional purpose, allowing a seeing organism to make important discriminations and associations, allowing it to utilize affordances in their environment.
But, some philosophers ask, can’t we imagine a situation where two people’s perception of color are inverted? Maybe my red is your green, and we’ve spent our entire lives using the words “red” and “green” to mean different experiences. In other words, when you see grass, you see my version of red, but call it “green”. Maybe for you my red is the soothing color of much of nature and my green the attention grabbing one of blood and roses.
A closely related issue is our inability to describe a color to someone born blind. We can describe colors in terms of their associations, such as yellow being with the sun, bananas, or egg yolks. But, the usual point is, we can’t describe yellow itself, or any other color.
Which leads to the question, doesn’t that indicate a non-functional ineffable aspect in the experience of color?
The answer depends on whether there’s more to red, green, or yellow than the associations and reactions they generate in us, that there’s some “mental paint” separate and apart from all those relations. If there isn’t, then the answer is no; the functional structure and relations provide a full account. It certainly doesn’t feel like that’s the case, but it wouldn’t be the first time strong intuitions led us astray.
The question is, if associations and reactions are all that’s there, why do we feel there’s more? It might have something to do with many of these associations and reactions being below the level of consciousness, although many of the resulting impressions aren’t. That produces an experience of mental paint whose origins we can’t introspectively trace.
There is an intense debate in anthropology on whether humans in different cultures see the same colors. If colors are just learned associations, then it seems plausible that different cultures see different colors. Consider a rainbow. In reality it’s a smooth spectrum of wavelengths with no stripes except for the ones our nervous system interprets to be there. Someone with a different background might literally see a different rainbow.
The question is whether they really see different colors, or simply divide up the spectrum with different labels. How much does language reflect the consciousness of the native speakers? And how much does that language in turn affect their consciousness?
One response to the color relativists is that we do all seem to have innate responses to particular colors, such as red having the attention grabbing effect it does. Similar responses actually show up in other primate species.
But this is complicated by the fact that we all have different ratios of photoreceptor cells in our retina that are sensitive to short, medium, or long wavelengths of light. And our ability to discriminate colors reportedly diminishes with age. Which seems to indicate there are variances in the signals and processing between individuals, and even within the same individual over time. This seems particularly borne out by the infamous “dress” incident a few years ago, where people looked at the same photograph but saw different colors, with many adamant that the version they perceived was the right and true one.
All of which seems to point in the direction of color being described by the reactions and associations it generates in us. In this view, colors are categorizing conclusions of our visual system. Some associations and reactions may be innate, but many are learned. And the “mental paint” of our visual field is the collection, the pattern, of those conclusions.
But what about our intuitions from the possibility of inverted qualia? Consider an alternate scenario introduced by other philosophers. What if my pain is your pleasure? Every time I use the word “pain”, I’m referring to the sensation you know of as pleasure. The question is whether this is a coherent scenario. If pain doesn’t cause the same reactions in you that it does in me, is it meaningful to call it “pain”? Likewise, is it meaningful to talk about a green that has all the reactions of red in your nervous system?
If the answer is no, then all qualia are categorizing conclusions of our nervous system, with no sharp distinction between them and the conclusion my laptop reaches when it scans my face for login. As a functionalist, that’s my conclusion. At least for now.
What do you think? Are there reasons to believe in non-functional aspects of qualia that I’m missing? Or other reasons to doubt the functional account?