More support for the illusionist perspective in a paper from Daniel Shabasson. He agrees with Keith Frankish that phenomenal consciousness is an illusion, and (taking the metaproblematic road) offers a theory as to why so many people – the great majority, I think – find it undeniably real in spite of the problems it raises.

Shabasson’s theory rests on three principles:

• impenetrability,
• the infallibility illusion, and
• the justification illusion.

Impenetrability says that we have no conscious access to the processes that produce our judgements about sensory experience. We know as a matter of optical/neurological science that our perception of colour rests on some very complex processing of the data detected by our eyes. Patches of paint or groups of pixels emitting exactly the same wavelengths of light may be perceived as quite different colours when our brains take account of the visual context, for example, but the resulting colours are just present to consciousness as facts. We have no awareness of the complex adjustments that have been made.

This point is particularly evident in the case of colour vision, where the processing done by the brain is elaborate and sometimes counter-intuitive. It’s less clear that we’re missing out on much in the way of subtle interpretive processing when we detect a poke in the eye. Generally though, I think the claim  is pretty uncontroversial, and in fact our limited access to what’s really going on has been an important part of other theories such as Scott Bakker’s Blind Brain.

Infallibilty says that we are prone to assume we cannot be wrong about certain aspects of our experience. Obviously most perceptions could be mistaken, but others, more direct, seem invulnerable to error. I may be mistaken in my belief that there is a piano on my foot, or about the fact that my toe is crushed; but surely I can’t be wrong about the fact that I am feeling pain? Although this idea has been robustly challenged, it has a strong intuitive appeal, perhaps partly out of a feeling that while we can be wrong about external stuff, mental entities are perceived directly, already present in the mind, and therefore immune from the errors that creep in during delivery of external information.

Justification is a little more subtle; the claim is that for any judgement we make, we believe there is some justification. This is not the stronger claim that there is good or adequate justification, just the view that we suppose ourselves to have some reason for thinking whatever we think.

Is that true? What if I fix my thoughts on the fourth nearest star to Earth which has only one planet orbiting it, and judge that the planet in question is smaller than Earth? If I knew more about astronomy I might have reasons for this judgement, but as matters stand, though I feel confident that the planet exists, I have no reasons for any beliefs about its size relative to Earth.

In such a case, I believe Shabasson would either point to probable justifications I have overlooked (perhaps I am making a mistaken but not irrational assumption about a correlation between size and number of planets) or more likely, simply deny that I have truly made the relevant judgement at all. I might assert that I really believe the planet is small, but I’m really only playing some hypothetical game. I think in fact, Shabasson can have what he needs for the sake of argument here pretty much by specification.

Given the three principles, various things follow. When we judge ourselves to be having a ‘reddish’ experience, we must be right, and there must be something in our mind that justifies the judgement. That thing is a quale, which must therefore exist. This follows so directly, without requiring effortful reasoning, it seems to us that we apprehend the quale directly. Furthermore, the quale must seem like something, or to put it more fully, there must be something it seems like: if there were nothing a quale were like, there would be no apparent difference between a red and a green quale; but it is of the essence that there are such differences.

What is it like? We can’t say, because in fact it doesn’t exist. Though there really are justificatory properties for our judgements about perceptions, they are not phenomenal ones; but impenetrability means we remain unaware of them. Hence the apparent ineffability of qualia. Impenetrability also gives rise to an impression that qualia are intrinsic; briefly it means that the reddish experience arrives with no other information, and in particular nothing about its relation to other things; it seems it just is. Completing the trio, qualia seem subjective because given ineffability and intrinsicality, they are only differentiable through introspection, and introspection naturally limits access to a particular single subject.

I don’t think Shabasson has the whole answer (I think, in particular, that the apparent existence of qualia has to do with the particular reality of actual experience, a quality obviously not conveyed by any theoretical account), but I think there are probably several factors that account for our belief in phenomenal experience, and he gives a very clear account of some significant ones. The use of the principle of justification seems especially interesting to me; I wonder if it might help illuminate some other quirks of human psychology.