Now people have a variety of ways to dismiss these issues. For example, there’s the notion of intelligence as an ‘emergent phenomenon.’ That is, we don’t really need to understand the computational system of the brain because intelligence/consciousness/whatever is an ‘emergent phenomenon’ that somehow arises from the process of thinking. I promise: anyone telling you something is an emergent property is trying to distract you. Calling intelligence an emergent property is a way of saying ‘I don’t really know what’s happening here, and I don’t really know where it’s happening, so I’m going to call it emergent.’ It’s a profoundly unscientific argument. Next is the claim that we only need to build very basic AI; once we have a rudimentary AI system, we can tell that system to improve itself, and presto! Singularity achieved! But this is asserted without a clear story of how it would actually work. Computers, for all of the ways in which they can iterate proscribed functions, still rely very heavily on the directives of human programmers. What would the programming look like to tell this rudimentary artificial intelligence to improve itself? If we knew that, we’d already have solved the first problem. And we have no idea how such a system would actually work, or how well. This notion often is expressed with a kind of religious faith that I find disturbing.
Freddie’s important point reminds of of a comment in Paul Bloom’s recent essay in the Atlantic on brain science: “Scientists have reached no consensus as to precisely how physical events give rise to conscious experience, but few doubt any longer that our minds and our brains are one and the same.” (By the way, I don’t know what Freddie’s precise views are on these questions of mind, brain, and consciousness, so he might not agree with where I’m taking this.) Bloom’s statement that cognitive scientists “have reached no consensus” on how consciousness arises rather understates things: it would be better to say that they have no idea whatsoever how this happens. But that’s just another way of saying that they don’t know that it does happen, that “our minds and our brains are one and the same.” It’s an article of faith.
The problems with this particular variety of faith are a significant theme in David Bentley Hart’s The Experience of God, as, for instance, in this passage:
J. J. C. Smart, an atheist philosopher of some real acuity, dismisses the problem of consciousness practically out of hand by suggesting that subjective awareness might be some kind of “proprioception” by which one part of the brain keeps an eye on other parts of the brain, rather as a device within a sophisticated robot might be programmed to monitor the robot’s own systems; and one can see, says Smart, how such a function would be evolutionarily advantageous. So the problem of how the brain can be intentionally directed toward the world is to be explained in terms of a smaller brain within the brain intentionally directed toward the brain’s perception of the world. I am not sure how this is supposed to help us understand anything about the mind, or how it does much more than inaugurate an infinite explanatory regress. Even if the mechanical metaphors were cogent (which they are not, for reasons mentioned both above and below), positing yet another material function atop the other material functions of sensation and perception still does nothing to explain how all those features of consciousness that seem to defy the physicalist narrative of reality are possible in the first place. If I should visit you at your home and discover that, rather than living in a house, you instead shelter under a large roof that simply hovers above the ground, apparently neither supported by nor suspended from anything else, and should ask you how this is possible, I should not feel at all satisfied if you were to answer, “It’s to keep the rain out”— not even if you were then helpfully to elaborate upon this by observing that keeping the rain out is evolutionarily advantageous.
I highly recommend Hart’s book on this topic (and on many others). You don’t have to be a religious believer to perceive that eliminative materialism is a theory with a great many problems.