I’ve previously argued against the more intuitive, default form of dualism that religious people tend to believe in. But moving past our first guess at how consciousness works is only the first step. Among those who reject the notion of a ghost in the machine, there is a wide range of opinion. There is by no means a consensus view among secular philosophers of mind regarding the nature of consciousness (though neuroscientists are pretty much uniformly working along the materialist paradigm and are happily making progress). There’s no way I could do justice to every serious possibility that’s been considered by philosophers of mind, but I still want to briefly mention the other most popular ideas among naturalistic thinkers.
Property dualism, which is far more modest than substance dualism, is the view held by David Chalmers, the philosopher who coined the phrase ‘the hard problem of consciousness’. Property dualists don’t believe that there are two different substances, but instead believe that mental properties can’t be reduced to the physical matter that we currently know about. There’s only one kind of stuff, physical stuff, but mental properties are so unusual and so unexpected, according to property dualists, that we need to be entirely open-minded to explanations that may appear uneconomical. They essentially believe that we can’t fully explain consciousness as only brain activity as we currently understand it, though what is missing from our explanation is something entirely naturalistic.
Panpsychists are a specific group of property dualists who take the position that something fundamental must be missing from our current picture of the universe. They don’t believe it’s possible for collections of unconscious atoms to become conscious without invoking any additional ingredients. Their solution to the hard problem of consciousness is to argue that all things in physical reality, down to fundamental particles, have some mental properties. So even electrons are conscious, though just a little bit conscious. They hold the view that the basic physical constituents of the universe have mental properties, whether or not they are part of a living organism. Panpsychists argue that the phenomenal properties of consciousness must be present to some degree on the fundamental levels of the universe. If consciousness wasn’t an inherent part of matter to some extent, no collection of atoms would ever become conscious. The philosopher Thomas Nagel famously argued that panpsychism at least appears to follow from a few uncontroversial premises. If human beings are made strictly of matter, and phenomenological states of consciousness are truly something new, then the matter that makes up humans must have further properties that we have not yet discovered. At least at face value, this doesn’t appear to contradict any of the materialist evidence that I presented in Science vs. The Soul. The appeal of panpsychism is that it offers a sort of middle ground between materialism and dualism. So the hard problem is fully acknowledged as a hard problem, without giving too much ground either way. There’s no way I’m aware of to test the claim that a rock or a bacterium might be conscious. One of the most common criticisms of panpsychism is that it’s unfalsifiable and that’s a serious problem. There are several different kinds of panpsychist and as strange as it may sound at first, it’s not so easy to argue against the reasoning behind it.
Another position known as epiphenomenalism holds that mental events are caused by brain events, but those mental events have no causal power whatsoever. In the 19th century, Thomas Huxley likened phenomenal properties of consciousness to the steam coming from a train. According to this view, consciousness is a byproduct of the brain and is causally impotent. Epiphenomenalism has a bad reputation right now, but it’s hard to see exactly why, other than the fact that it clashes with our intuitive judgement and implies that our subjective experience of our conscious intentions causing our movements is an illusion. Epiphenomenalism is different from the materialistic conception of emergence, where new properties can emerge from more fundamental systems; or new processes emerge from other, more fundamental processes. The materialist view of consciousness I argued in favor of in those two episodes doesn’t necessarily entail epiphenomenalism. Sean Carroll wrote a helpful blog post I’ll link in the description on the issues with downward or upward causation; meaning causation between different levels of emergence, rather than strictly within one level. The punchline is that you can’t start a sentence on one level of emergence and end it in another. You have to stay consistently on one level for causation to be the proper concept to be invoking. So according to a materialist like Sean Carroll, consciousness does emerge, but it can be causally potent on it’s own level of emergence. If you want to speak on the level of neurons firing, you can’t coherently end your thought on the level of people walking around and making conscious decisions. There’s no downward causation and no upward causation. But as for epiphenomenalism, the evidence appears to show that at least in some cases, our intuitive judgments that our conscious intentions are causing our movements must be illusory.
Naturalism and Language
All these disparate and sometimes odd views on consciousness are held by people who don’t believe in any gods and aren’t religious. You can remain a naturalist and still think we’re missing something from our current picture of the universe. Scientists tend to be materialists, and I’m a materialist; but of course, I’m always open to new evidence and arguments. I fully acknowledge that there are as of yet unexplained mysteries in our extremely strange universe. But “mysterious” doesn’t imply “non-naturalistic”. Our bias is to want an absolute answer, even if that answer is terrible; and all the non-naturalistic attempts to answer mysterious elements of our universe have been terrible. I’m really not afraid to admit that I don’t know the answers to all kinds of questions, and that I don’t like not knowing. But I would rather not know and die not knowing than abandon rational and skeptical thinking to accept a mystical, superficial non-explanation so I can satisfy my urge to have some kind of answer.
It’s also important to point out in any discussion of consciousness that there’s a basic communication problem here. We don’t really have the language to speak about this issue in such a way that everyone knows exactly what we mean all the time. Not everyone is talking about the same thing when we use the common list of words and phrases used in these discussions, so we end up talking past each other a lot. It’s hard to speak coherently about the nature of consciousness when our vocabulary is so imprecise and fuzzy. So a major barrier to explaining and understanding consciousness is simply our lack of good language to describe and discuss it.
In a related vein is a view called mysterianism that has some mainstream popularity. Mysterianism feels a little fatalistic, but it might be true and I’m fairly sympathetic to it. There are times when our intuitions simply hit a wall, and consciousness may be one of those times. We may never get an intuitively satisfying answer to this question, just like we’ll never have an intuitively satisfying answer to whether the universe is infinite or finite. Both possibilities there seem absurd to me and equally hard to imagine concretely. And it’s not as if theists are any better off — god doesn’t help to make an infinite or finite universe easier to imagine to our minds. There are no doubt genuine instances of facts that are not graspable because of the constraints of our brains. Why would we expect anything else, given who we are and how we got here? Our intuitions evolved to help us survive and reproduce as social animals in our environments. They’re great for Newtonian physics and detecting subtle social cues; they’re mostly trustworthy within their domains. But our minds did not emerge so we could be able to understand fundamental questions about the universe; there’s no adaptive advantage to understanding quantum mechanics. In fact, you would have been selected against had you been walking on the savannah contemplating the nature of the universe rather than paying attention to your more immediate predicaments. To add something on top of materialism, we’ll need more than an intuitive complaint. This isn’t to say that we’ll never understand anything about consciousness, since we already know quite a lot and progress is moving along steadily. But our intuitions may never be fully satisfied, even if we have abundant evidence that a given scientific model is true. It’s completely possible that our brains just aren’t complex enough to fully understand themselves.
Panpsychism [Stanford Encyclopedia of Philosophy]
Causation and Emergence – Sean Carroll [PreposterousUniverse]