Sunday, February 27, 2011

Qualia and Operationalism

“Phenomenology,” the study of the qualities of experience, has a long history in both Eastern and Western philosophy. In its modern European version phenomenology has two post-Enlightenment roots. First, in its claim that experience has its own structure that can (and must) be explicated in order to establish the foundations of epistemology, the phenomenology of Husserl and Heidegger is thoroughly Kantian (by way of 19th century German transcendental idealism), as are the subsequent “Continental” movements of structuralism, deconstructionism etc. (Merleau-Ponty, with his emphasis on the role of the whole body in defining the phenomenal field, is an exceptional character in this community, and I will have something to say about Sartre in the discussion of Buddhism below.) Second, modern phenomenology is a response to the dramatic development of modern science and particularly to the perceived threat posed to humanism by the potential triumph of empiricism and the resulting absorption of the study of human nature into physical science.

It is not hard to see, then, why the naturalist movement in philosophy of mind, primarily a movement of English-language philosophers and scientists, resisted acknowledging the troublesome significance of phenomenology through the middle of the 20th century. A partisan narrative developed where the “Continentals” were resolutely non-scientific (holding, as they mostly did, that phenomenology was wholly autonomous from physical science) and often anti-scientific while the “Analytics” studiously ignored phenomenology and developed materialist philosophy of mind as part of a larger interdisciplinary (and largely empiricist and scientific) movement that eventually came to be called cognitive science, and that for its first fifty years or so had a strong ideological commitment to operationalism, and to some extent still does. Only in the past few decades has “consciousness studies” become an active area for cognitive scientists.

This doesn’t mean that phenomenology didn’t bedevil the naturalists from the first. The first major operationalist movement, behaviorism, had many variants, a lively theoretical literature and was an impressive generator of experimental protocols, but as a popular psychology (a theory of psychology intuitively persuasive to the average person) behaviorism was never really even a candidate for widespread acceptance, and the essential (popular) problem was, without doubt, behaviorism’s manifest failure to accommodate ordinary intuitions about qualia.

The primary motivation for behaviorism was to make a science of psychology. The primary strategy was methodological: strictly hew to the methods of empirical science and ipso facto science will be the result. This operationalist ideology entailed the elimination of reference to “unobservables.” Behaviorism developed a semantic for psychological words that held that psychological predicates referred to intersubjectively observable dispositions to behave. There is more to be said for this approach than is commonly recognized nowadays; Wittgenstein, who had much to tell us about the problem of meaning, also advanced what I find to be persuasive arguments about qualia and I will return to him in what follows. However at the moment we want to see how behaviorism, popularly understood, floundered over the problem of qualia.

Consider the word “pain.” If we take the behaviorist line in its literal, popularly-understood sense the word “pain” refers to wincing, grimacing, certain vocalizations (such as “ouch!”) and so forth. One problem with this is that the set of behaviors that might be identified as pain behaviors is indefinitely large (that is, it is not apparent what parameters fix the extension of the set), and there are other problems, but the crucial problem in the current context is that most people have a strong intuition that wincing, grimacing and so forth are caused by pain, that is that the word “pain” in fact refers to the feeling of pain and furthermore that this feeling is playing a causal role in the production of the “pain behavior.”

Behaviorism’s more sophisticated descendent, functionalism, turned out to be no better able to handle the issue of conscious qualitative experience. Consider this problem for functional-role semantics, which holds that the “meaning” of a word is nothing more or less than what the speaker achieves by its utterance: imagine a person whose color spectrum is inverted. Where ordinary people see red, this person sees blue and vice versa. However, growing up in the same linguistic community, this person would use color words exactly like the rest of us. Ask the inverted-spectrum person to, say, go out to the car and get the blue bag and they will return with the correct bag just as reliably as anyone else. But, the defender of phenomenology argues, what everyone else means by “the blue bag” is the bag with that quale, which is the ordinary person’s experience of the color blue: and the “invert” does not have that experience.

Here one might respond by pointing out that we have no way of knowing if any two people experience “blue” surfaces the same way. This is Wittgenstein’s point with the analogy of the beetle in the box: it can’t be that the phenomenal word refers to an individual’s private experience. At this point the defender of qualia ups the ante. Suppose there was a person who behaved, responded and so forth in appropriate ways such that they seemed to take psychological predicates just as naturally as everyone else. Imagine further, however, that this person had no private experience: a non-conscious “zombie.” Surely, the argument goes, one couldn’t consider such a creature to be a “person”? Surely we mean by “person” a being that has some experience? Aldous Huxley in his novel Brave New World, an early critique of operationalism’s qualia problem, is making the same point: when the quality of experience comes to be considered simply insignificant for “psychology” then that discipline is no longer what most people would consider to be psychology at all.

This whole genre of thought experiments comes together as the “absent qualia” argument. The argument is that complete functional descriptions fail to capture the quality of experience just as utterly as complete physical descriptions do. One of the biggest successes in philosophy of mind in recent years has been the work of David Chalmers, who argued in The Conscious Mind that, faced with the problem of qualia, we have no choice but to concede that materialism is false and that reality includes at least two kinds of properties, physical properties and phenomenal ones.

The philosophy of mind community acknowledged the problem of consciousness in the 1970s and 80s through some seminal work by Ned Block, Frank Jackson, Saul Kripke, Thomas Nagel, John Searle and others. Prior to Chalmers the “mysterians” such as Colin McGinn had argued for a kind of epistemological (or “property”) dualism (we must concede that consciousness cannot be incorporated into physical science, but maybe we can concede this without giving up materialism). But Chalmers’ sporting brief for metaphysical dualism represents a kind of apotheosis for the problem.

I read Chalmers as writing in a Berkleyan spirit. John Locke elaborated a system of various “properties.” There were primary properties, the essential physical properties of the object; secondary properties, the causal properties of the object such that it caused the mental representation to be as it was; and tertiary properties, the properties of the representation (Locke would say “impression”). In other words a fairly messy tangle. Berkeley, whose views appear strange when presented out of context, made what was in fact a common-sense (and thoroughly empiricist) suggestion: if the mental representation (the “idea”) is the only thing that we, in actual fact, experience, and there is an intractable problem about the relationship between the idea and the “material world,” why don’t we cut the Gordian knot by simply saying that ideas are constitutive of the world, and be done with the problematic “matter” altogether? After all we can only know about the ideas. So let’s just call our ontology “idealism” and move on. Chalmers’ move is very similar: embrace mind-body dualism so that we can forget about it.

I appreciate Chalmers not only because he is audacious, but because he focuses on the metaphysics, which is where the problem and any possible solution of the problem of consciousness lie. The key strategic move in the present book is to point out that “mind” is a heterogeneous concept. Thus we have not one “mind-body problem” but (at least) two. Granting this we can apply different theories to different problems without self-contradiction. In the last chapter I advanced a version of meaning externalism as the right semantic of intentional predicates, to replace the representationalist account. The view that intentional predicates refer not to mental contents but to relationships between whole persons and their environments is essentially an operationalist view. At the same time I do not think that any kind of operationalism will do for phenomenal predicates; that is, I agree that the absent-qualia problem cannot be overcome by any operationalist strategy. The problem of consciousness needs an entirely different treatment than the problem of intentionality.

However the only sort of “dualism” that I am willing to consider seriously is the dualism of form and matter to which I appealed in the discussion of rationality (and I take that to be a major concession). The question of the form-matter distinction is an interesting question for general metaphysics (and physics), and it is at the level of general metaphysics that it will have to be resolved one way or another: it is not ultimately, I argue, a problem particular to the metaphysics of mind. So the hope for a natural semantic of psychological predicates is still alive, granting that human beings may be possessed, like everything else in nature, of formal properties that are different from physical properties. Other than that (admittedly major) caveat, it is my view that there are only physical properties. So I will now have to argue that there are no phenomenal properties. A successful argument will have to persuade the reader that the absent-qualia problem has been satisfactorily addressed.

In fact three arguments (or perhaps three versions of one argument) will now be presented, drawing from three separate canonical sources. As in the discussion of Plato in the last chapter, it is not so much my goal to explicate the canonical sources with an historian’s precision as it is to use some excellent philosophy as a springboard and inspiration. This does not mean that I am giving myself a license to anachronism or idiosyncrasy. I am simply asking the reader to consider the arguments (and the interpretations) on their merits as they pertain, if at all, to the problem of phenomenal properties. The second part of the chapter will again appeal to heterogeneity and explore the implications of recognizing that consciousness, unlike intentionality, is not a supervenient quality. When this is recognized it turns out that we can avail ourselves of a kind of materialist theory that fails when used to address intentionality

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