The gist of the article: Most theorists subscribe either to the “realist” or the “illusionist” theories of consciousness. Realists suggest that the brain activity underlying sensations has consciousness latent in it as an additional property of matter, not yet recognized by physics. Humphrey is an illusionist. He believes that the sensations you experience are an illusion, a trick your brain is playing on you. But that notion is distressing to a lot of people. To make this idea easier to swallow, Humphrey wants to recast it as art: your brain is putting on a magnificent performance for your benefit.
Quoting from the article:
The fundamental nature of consciousness remains a scientific mystery… The problem is that one aspect of it continues to baffle everyone, and that’s the “feel” or “phenomenal character” of consciousness – or as philosopher Thomas Nagel has put it, simply “what it is like.” Biologist H. Allen Orr probably speaks for most scientists when, in a recent review of Nagel’s book Mind and Cosmos, he writes: “I share Nagel’s sense of mystery here. Brains and neurons obviously have everything to do with consciousness, but how such mere objects can give rise to the eerily different phenomenon of subjective experience seems utterly incomprehensible.”
Theorists tend to fall into one of two camps. Some assert that the manifestly eerie and ineffable qualities of subjective experience can only mean that these nonphysical qualities are inherent in the fabric of the universe. Others, including me, argue that consciousness may be more like a conjuring show, whereby the physical brain is tricking people into believing in qualities that don’t really exist.
But no one wants to be told the latter story! So I am going to try telling the story in a different way. While I believe consciousness may indeed be a stage trick by the brain, I want to suggest that it is also a stroke of artistic genius. Consciousness as art is surely a more palatable notion than consciousness as an illusion.
I’ll come back to Humphrey’s discussion of consciousness as art. First, I want to continue with his line of thinking and delve into the realist vs. illusionist question.
On the question of what consciousness is:
Although opinions differ, I think it is helpful to start by describing consciousness simply as introspective access to mental states. That is to say, you, the subject of consciousness, are conscious of mental states – perceptions, memories, wishes, and so on – just in so far as you know about them by looking in on your own mind.
Note that we encounter only one you here… Your perceiving self, your remembering self, your acting self became merged into one big you… With all this activity happening on a single stage, consciousness has become something like a theater, where the engine of the mind is on show. You can reflect on what’s going on. And this capacity for self-reflection supports a second important function of consciousness: to allow you to appreciate how your mind works.
The picture that is emerging may not be incomprehensible but neither is it eerie. Where’s the peculiar what-it-is-like-ness that Nagel pointed to?
We should note that the quality in question does not pervade every aspect of consciousness… I’d say this quality is not a feature of higher levels of cognition. There is no “what it is like” for you to have the thought that two plus two is four. Rather this quality seems to kick in only at a more animal level, in the way you represent what’s happening at your bodily sense organs. Of the variety of mental states of which you’re conscious, it is your sensations – and only your sensations – that have this peculiar dimension to them.
The special qualities of sensations are what philosophers call “qualia.” Although scientists don’t often use that term, there’s no denying that qualia present natural science with a spectacular challenge. Christof Koch wrote to me that “it is bizarre that brain matter should exude these phenomenal feelings. Consciousness is so vivid, and its properties appear so otherworldly, that it seems to call for God.”
I think Humphrey is contradicting himself here. On the one hand, he says the “what it is like” quality only exists around physical, bodily sensations. On the other hand, he notes that you can be conscious of how your own mind works. I can say without a doubt that it is “like something” to be aware of my own thought process. Suppose I’m sitting still trying to come up with a word that fits into a vexing spot in a crossword puzzle. It is certainly “like something” to experience the mental search for the solution, and it’s “like something” else when I suddenly think of the answer.
Most theorists now accept that only two options can be taken seriously… We can be realists about qualia, or else we have to be illusionists. Unfortunately, both options come at considerable price.
Realists take qualia at face value. In their view, if your sensations appear to have qualities that lie beyond the scope of physics, then they really do have such qualities. And these realists explain their reasoning by suggesting that the brain activity underlying sensations already has consciousness latent in it as an additional property of matter – a property as yet unrecognized by physics but one that you, the conscious subject, are somehow able to tap into. The price for this explanation is that it implies that the standard physical description of the world is radically incomplete.
Illusionists take the contrary line. If your sensations appear to have these qualities, then your physical brain is playing tricks on you. Your brain can pull off such magical effects because it houses a computational engine that deals in symbols, and physically based symbols can perfectly well represent states of affairs that do not and could not exist. The price for this explanation is that it devalues not only the mystery but the majesty of the core experience.
Humphrey goes on to discuss why we are uncomfortable with the idea of consciousness being an illusion, and how thinking of consciousness as a performance, a work of art that our brains create for our benefit, might be easier for us to swallow.
While there is nothing scientific about Humphrey’s suggestion that we consider consciousness as a work of art, it’s an interesting and entertaining perspective and I would not argue with it. But I cannot buy “illusionist” theory, at least as Humphrey describes it.
Of course, it must be the case that neural activity in the brain creates what we experience as consciousness: awareness of both the external world and our own internal states. But to say that your brain is tricking you into believing that you are having subjective experience seems absurd on the face of it. Where is this “you” that’s being tricked? It’s not possible to trick a rock into believing something. Only a conscious being is susceptible to being tricked. Humphrey’s position seems to be that the brain is tricking a conscious being into believing it is conscious. In other words, in order to make his case he is implicitly postulating the reality of the very thing he is denying.
So it seems to me that the illusionist theory of consciousness collapses in on itself. But I do not necessarily buy into the realist explanation of consciousness as an additional, unrecognized property of matter, either.
Consciousness is certainly a mystery. But as we recognize we have little understanding of how consciousness is created, what sense does it make to claim that there are only two possible explanations for it?