In 2017, the TLS published a debate about consciousness between David Papineau and Daniel Dennett, focusing on issues raised in Papineau’s review of Dennett’s 2017 book, From Bacteria to Bach and Back. (The debate is behind a paywall, but with limited free access.) Tim Crane, who edited the debate, suggested that I might like to add my thoughts on the exchange in the comments section, which I did. This has seems to have been removed from the TLS site, so I have reproduced it here.
I thought this was a useful exchange, but the conciliatory tone on which it ends left me puzzled about the extent of the difference between the participants’ views on consciousness. Both agree that conscious experiences are physical brain states and that we can internally monitor these states and report their occurrence in us. Yet they differ over what this internal monitoring reveals to us. Papineau holds that we are introspectively aware of phenomenal properties of our experiences, whereas Dennett denies that we are.
This looks like a huge disagreement, but is it really? It depends on what we mean by ‘phenomenal properties’. Papineau glosses the term as ‘properties like being in pain or seeing something red‘. On one reading of this, Dennett can agree that we are aware of such things. As noted, he holds that we can internally monitor our mental states and tell introspectively what experiences we are having. What he denies is that introspection reveals anything about the intrinsic nature of these states. When we have a pain or an experience of red, we are aware only of the property represented (the condition of some part of our body, the redness of some external surface), not any intrinsic properties of the mental state that does the representing. It may seem to us that introspection reveals intrinsic properties of experiences, but this, Dennett maintains, is an illusion.
Papineau disagrees, however. If I understand him right, he uses ‘phenomenal properties’ to refer to intrinsic, nonrepresentational properties of experiences. On his view, introspection doesn’t just reveal that we are having a pain or seeing red, but what these experiences are like in themselves. It does not, however, reveal these properties to us in their true nature, as physical properties of the brain, and this limitation misleads us into thinking that consciousness is mysterious and nonphysical.
On the face of it, Papineau’s position — which is, as he notes, the mainstream physicalist one — may seem more plausible. But I’m not sure it is a stable one. One worry is that introspection doesn’t just fail to present consciousness as physical, but positively presents it as non-physical. When I have an experience of red, I’m tempted to judge that I am directly presented with an ineffable mental redness — which may or may not have been caused by something red in the real world (think of an afterimage). ‘This redness here’, I might say, trying to gesture inwardly at the property I mean. And it’s very hard to see how a physical brain state (a collection of neuronal spike trains, in Dennett’s words) could have a property like that. Certainly, no investigation of my brain would reveal anything like it.
One response to this would be to say that, although we do have introspective access to intrinsic properties of our experiences, introspection misrepresents these properties as having a qualitative nature they in fact lack. (This view has been defended by the American philosopher Derk Pereboom.) I think this is a coherent position, but it would be misleading to call the properties involved ‘phenomenal’, since that term suggests that they do have a qualitative nature. (I have suggested calling them ‘quasi-phenomenal’.) On this view, then, phenomenal properties, properly so called, are illusory — a view that is very close to Dennett’s.
I am unsure whether Papineau would endorse this view. He seems to agree with Dennett in dismissing qualia, understood as mysterious entities constituted by the appearances of things, but he might want to insist on the reality of phenomenal properties in some sense intermediate between full-blown qualia and quasi-phenomenal properties. Perhaps such a view could be defended, though I am sceptical. At any rate, I think that Papineau and other physicalists should at least allow the possibility of a thoroughgoing illusionism about phenomenal properties. For if we are wholly physical beings, then our introspective access to our experiences must be mediated by some physical mechanism, and it is possible that such a mechanism could consistently misrepresent them as having properties they do not in fact have.
In the end, I remain unsure about the extent of the disagreement between Dennett and Papineau. It is, however, a disagreement between allies, and on one crucial point they are agreed: that the philosophical puzzle of consciousness arises in large part from the limitations of introspection.