David Chalmers often — rightly — presses me to clarify exactly what it is that I and other illusionists deny. We say that we deny the existence of phenomenal properties, or qualia, but what exactly do we mean by this? Here, it seems, we illusionists face a dilemma. Is the notion of a phenomenal property a theoretical one or an observational one?
Suppose we say that the notion is a theoretical one — say, that of a property of experience that is nonphysical, not publicly observable, and immediately known. Then phenomenal realists such as Chalmers will say that that’s not what they mean by a phenomenal property. They mean simply the feel of experience — what it’s like. They do not define these feels as having features such as non-physicality, though they have arguments for thinking that they do in fact have them. Thus, if illusionists take this option, they are not denying the existence of properties realists believe in, but merely denying that those properties have the features many realists believe they have. Chalmers will be more than happy to engage with them on the latter point.
Suppose, then, that illusionists say that the concept of phenomenality is an observational one — the concept of the kind of feature people detect when they introspectively detect that they are having an experience of some kind. Then illusionists are denying something realists believe in, but also, it seems, making the absurd claim that experiences have no introspectively detectable aspect — that you detect nothing when you detect that you’re in pain!
This is the dilemma facing the illusionist. Francois Kammerer has likened it to the task Odysseus faced in navigating his ship between the two sea monsters Scylla and Charybdis. (See his talk ‘Defining consciousness and denying its existence’ at a workshop in Bochum.) What should the illusionist do?
The short answer is that they should reject the dichotomy and point out that all observation, including introspection, is theory-laden and that the concepts we employ in introspection are themselves infused with theoretical commitments. This is the line Kammerer takes, and I think it’s right. I won’t develop the response here, however. (I discuss the issue at much more length in a new paper forthcoming in a special issue of the French journal Klēsis, edited by François Loth.) Instead, I want to point out that illusionists can pose a parallel dilemma for the realist.
Here’s how they can do it. First, they need to sketch some positive account of what consciousness is, couched entirely in terms of informational and reactive processes centred on the brain. For present purposes, the details do not matter; the crucial thing is that the account is framed entirely in functional terms. The realist will say that the account omits, or at least fails to explain, something — the central phenomenal aspect of experience. (Note that it does not matter whether the proposed account is actually true; the point is that the realist will claim to know a priori that it is not true, or at least not fully explanatory, since it misses out something crucial.) Now comes the dilemma. How do realists conceive of the missing properties?
Suppose they conceive of them in the observational way, as the properties people detect when they introspectively detect that they are having experiences, with no commitment whatsoever as to the nature of these properties. This option was unattractive to illusionists, but it is awkward for realists too. How can they know that the detected properties are omitted from, or not explained by, the illusionist’s account? Why should they even suspect that they are not included? After all, they claim to have no idea what the properties are.
Suppose, then, that realists allow that the notion of phenomenality does have a theoretical component after all, and that they conceive of phenomenal properties as having certain specific features. Then they can maintain that the illusionist account is inadequate, on the grounds that it omits or fails to explain properties with those features. But if they make this move, then illusionists can deny the existence of phenomenal properties without denying that experiences have an introspectively detectable aspect. For they can say that experiences have an introspectively detectable aspect but this aspect is not phenomenal. What you detect when you detect that you are in pain is not really a phenomenal property.
Sauce for the goose is sauce for the gander!
Where does this leave us? It leaves us having identified the core questions as, first, what theoretical commitments are packed into the notion of phenomenality, and second, whether experiences have phenomenal properties as characterized by those commitments.
In response to the first question, I’m inclined to say that the key commitments are to phenomenal properties being (a) not characterizable in functional terms and (b) clearly revealed to introspection. Other claims, such as that phenomenal properties are non-physical, resist scientific explanation, and are radically private, derive from those core ones. I discuss this more in the Klēsis article.
As for the second question, I answer in the negative, of course.