Specifically, I want to share some thoughts on the thorny cluster of mind-body problems, especially insofar as these thoughts help to flesh out points I inadequately gestured towards earlier, and insofar as they address Braun’s claim that a materialist view of consciousness actually does a better job than a dualist one of explaining how mental events such as deciding on the basis of reasons can cause physical changes in the brain.
In that comment, Braun takes it that mental events just are brain events. The argument seems to be this: Since there is no mystery concerning how brain events can cause other brain events—and since “deciding to do X” just is a brain event—it follows that there is no mystery about how “deciding to do X” can trigger neural firings that stimulate the rest of the body to do X. Since this “reductive materialist” view of the mind accounts so readily for mental causation, it actually does a better job of making sense of our experience than do dualistic views which posit two different kinds of substances—minds and bodies—and which then have to confront the difficulty of making sense of how they can causally interact.
This has been one of the standard arguments in favor of reductive materialism for a long time, which is one reason Goetz and Taliaferro spend so much time in their book, Naturalism, taking issue with the claim that causal interaction between non-physical minds and physical bodies poses such a challenge. The most important point they make in their response to this view is that there is a mystery about material causation, and hence about how brain events can cause other brain events—and that the most plausible solution to this mystery works just as well for dualistic mind-body causation. In other words, the latter is no more mysterious than the former.
But it’s not my intent here to repeat G&T’s arguments on this point. The deeper issue, for me, is the philosophical untenability of saying that mental phenomena just are brain phenomena. It is not similarly untenable to claim that mental phenomena are by-products of brain phenomena, or that mental phenomena and brain phenomena are distinct aspects of a more fundamental noumenal reality to which we do not have direct access (or, perhaps better, they are how this reality “looks” from two distinct perspectives—which is closer to my view).
The argument against such reductive materialism can be formulated in several ways. There is a “way it feels” to be the subject of an experience—say, the experience of observing the color red. Philosophers have come to call such things the “qualia” of conscious experiences (“quale” in the singular). Correlated with each quale is some repeatable sequence or pattern of neural firings (what I will call a “brain event”). But here’s the thing: I am immediately acquainted with color “qualia,” such as the subjective experience of red. I am not immediately acquainted with the corresponding brain events. As such, there is something that’s true of color qualia which isn’t true of corresponding brain events. But if something is true of X but not true of Y, then X and Y are not identical. Hence, conscious experiences are not identical with brain events.
The same idea can be arrived at via Frank Jackson’s famous arguments from his essay, “Epiphenomenal Qualia.”
Obviously, she has. She’s learned what red looks like. But by hypothesis she already knew everything there is to know about the neurobiology of color perception. And so the subjective experience of redness is not identical with the brain events that science studies.
None of this entails that mental phenomena cannot be construed as by-products or unique properties of brain events, thereby preserving a broadly materialist metaphysics. But it does entail that the simple reductive materialist solution to the problem of mind-body interaction evaporates. On the reductive materialist view, such things as “deciding to do something for a reason” just are brain events—and since (it is contestably assumed) there is no problem with brain events causing other brain events, there is no problem with explaining how deciding to do something for a reason can give rise to neural firings that trigger complex bodily behavior.
But insofar as “deciding to do something for a reason” directly describes a phenomenon of consciousness, and insofar as such a phenomenon is not identical with a brain event, this easy solution to the problem of mind-body interaction is no solution at all. On a materialist metaphysics, what causes the brain events that directly impel bodily activity are nothing more than other brain events. And since the conscious experience of “deciding to do something for a reason” is at best an epiphenomenal by-product or property of these brain events (rather than a brain event in itself), it cannot be what in ordinary human experience we take it to be, namely, the source of our activity. Deciding to do something for a reason is rendered as inefficacious in the world of human behavior as is the greyness of brain matter. Instead of causing our acts, it is just another effect, along with our actions, of brain events unfolding according to physical laws.
To this line of argument we can add a further argument specific to the distinctive conscious phenomenon that we call deciding something for a reason. Reasons are, by definition, conceptual. They have semantic content. Physical events do not. Hence, brain events do not. As such, to decide to do something for a reason is to act in a certain way because of a proposition with a conceptual content. And a proposition with a conceptual content is not reducible to a brain event. As such, if a brain event is responsible for my activity, then it is not true that I am acting on the basis of a reason. I am, instead, acting on the basis of a prior brain state giving rise to subsequent ones in accord with the physical laws regulating cause and effect. And so, on a reductive materialist metaphysics, there can be no such thing as doing something for a reason or deciding to do something for a reason. There can at best be an epiphenomenal conscious state that looks like acting for a reason. (To whom does it look this way? Well, that leads into other difficulties relating to making sense of the subject of experience given the assumption that the conscious self as we know it is wholly a product of the brain).
The final conclusion we are led to here is that a materialist metaphysics belies our ordinary self-understanding, specifically, our understanding of ourselves as agents who act for reasons. If we accept this metaphysics of reductive materialism, then our immediate conscious experience of ourselves, on this point at least, must be rejected as delusional.
And to reject our self-understanding on this point is nothing like, say, coming to believe that we have a subconscious mind in addition to the conscious one. Agency lies at the heart of just about every single aspect of our lived existence—only agents can be morally responsible for our actions; only agents can pursue creative endeavors or develop arguments or raise objections or think things through or take stands on issues. Deny agency, and these are merely things that happen to us, and my critics’ efforts to convince me to change my mind become nothing of the sort. Try as they might, they can’t try to convince me, because “trying” is conceptually linked to agency, and “convincing” someone is conceptually linked to agent-responsiveness to reasons as opposed just to mechanistic causes and/or quantum indeterminacy.
Put another way, agency is not just some feature of our self concept among others. It touches on every aspect of our self-understanding. Take it away, and one doesn’t just modify that self-understanding. One does away with it altogether. To strip us of agency is to strip us, in an important sense, of what makes us human. It seems to me that, all else being equal, a worldview that preserves our humanity in this sense is preferable to one that makes it out to be a Grand Delusion. The quest for such a worldview, one which also takes seriously everything we have come to know about our world through science, is therefore more than worthwhile.