What is the place of consciousness in the natural world? One of the main answers to this question is reductive physicalism. On this view, our states of consciousness are identical with broadly physical states, for instance, neurological states of the brain or more abstract computation-functional states. This view provides a simple and uniform way of integrating consciousness into the physical world.
However, in my project, I will develop three novel arguments against reductive physicalism. These arguments will developed in a book, The Emergent Mind: New Arguments Against Reductive Physicalism.
First, the argument from relational structure. Consciousness has a relational structure. Consciousness is always consciousness of something. Even in a case of visual hallucination, you are conscious of colors and shapes, so that you are in a position to know what they are like. Most views of consciousness – sense datum views, intentional views, and naïve realist views – recognize the relational structure of consciousness. But how might reductive physicalists explain the conscious-of relationship? How can the brain enable us to be conscious of colors and shapes, properties that needn’t occur in the brain at the time? I will argue, on empirical grounds, against our best reductive physicalist theories of the conscious-of relation. Consciousness can’t be reduced and won’t go away.
My second argument against reductive physicalism I call the argument from significance. The conscious-of relation is significant in a few ways. First, your relation to things you are conscious of is necessarily very different from your relation to things you are not at all conscious of. Second and relatedly, the conscious-of relation plays deep epistemic role: by being conscious of things, you have reasons to have certain beliefs about them. Third, the conscious-of relation has intrinsic normative value: it is because we are conscious that our existence has special value. However, I will argue, using a series of thought-experiments, that reductive physicalism is inconsistent with these truisms about the significance of consciousness.
My third and final argument against reductive physicalism concerns a puzzle about phenomenal thought, that is, our thought about our own phenomenal experiences. It depends on two plausible ideas. First, it is easy to think about our own experiences. For instance, if you suddenly have a horrible head pain, it is easy to notice and think about this type of state: roughly, in order for you to think about it, no elaborate set of background facts need to obtain. (Contrast physicists’ ability to refer to quantum-mechanical spin, which requires their knowing an elaborate background theory; or your ability to refer to the property being a game, which you do through first being exposed to many examples and acquiring a complex disposition to apply “game” to a certain open-ended range of activities.) Second, when you have the head-pain, it is not massively indeterminate what state you have in mind. Rather, there is this state you are in, and you are determinately thinking about it. I will argue that, under reductive physicalism, these two ideas cannot both be true. Since they are both very plausible, they give us yet more reason to reject reductive physicalism.
After rejecting reductive physicalism, I will develop an alternative emergentist theory of consciousness. On this view, something special happens in connection with brains of a certain complexity that is unlike what happens in the rest of nature. Our brains have an intrinsic capacity to enable us to stand in the conscious-of relation to a certain range of basic properties, where those properties needn’t be instantiated in the brain itself. Further, I will develop a consciousness-first approach to the mind. Rather than trying to reductively explain consciousness in other terms, we should take it as a starting point that be used in the explanation of cognition, reasons, and value. I will show how my positive view can provide a unified solution to my three problems for reductive physicalism: the problem of the relational structure of consciousness, the problem of the significance of consciousness, and the problem of phenomenal thought.