This post is in response to Kevin Moore’s posts about physicalism, evolution and consciousness at “The Placebic View”. I want to start by saying that I admire Kevin’s interest in philosophical positions to which he does not subscribe. Earnest examination of positions other than one’s own helps a person improve their own ideas and appreciate other people a little more. Here is some more grist for the mill.
This is my take on physicalism. I think it is not controversial to say that physicalist philosophy is a work in progress. There are a number of competing branches and sub-theories. For good or ill, I’ll only speak for myself and my non-professional understanding of the issues at hand.
1) It seems as if some things are up to me. For example, when I am deliberating over whether to, say, raise my hand or not, it seems as if I am in control over whether I actually endeavor to raise my hand. It does not seem to me as if such endeavorings are determined. Admittedly, such seemings do not entail the falsity of determinism, like seemings of pain entail the occurrence of pain. And, this means that if one were to infer the falsity of determinism solely on the basis of such seemings they would be going beyond their evidence and could very well be wrong. But, that doesn’t matter, here. All that matters for the success of this argument are the presence of such seemings; their veracity can be presently be ignored.
I’m not sure exactly what Kevin is getting at here. He is either talking about intentionality or the subjective quality of movement. I think it is the latter, and that is what I’ll address below.
Intentionality poses little difficulty for physicalism. What ever else intention is, it requires subjects and objects which are, or can be reduced to, entities having relative location and causal relations. Intention does not exist without such subjects and objects. Even when we think about love or a five-dimensional cube, we derive our ideas of these things from experience writ large, including the way in which we are predisposed at birth to feel about our parents and, with the proper exposure, perceive depth. No, intentionality is not the hard part, subjectivity is, and I think that is what Kevin is after here.
2) The naturalist worldview rests on the foundation of two seemingly indispensable pillars: Darwinian evolution (or something near enough) and physicalism. In brief, the theory of Darwinian evolution is suppose to be able to tell us why biological life is the way that it is and the physicalist theory is suppose to be able to tell us why everything is the way that it is. Without the support of both of these pillars, the naturalist worldview is hardly a worldview at all.
If physicalist theory is supposed to tell us why everything is the way it is and Darwinian evolution is supposed to be able to tell us why biological life is the way it is, then physicalist theory does not depend on Darwinian evolution and if physicalism undergirds a naturalist worldview, then neither does a naturalist worldview. Moving on.
3) Now, according to physicalism, everything must be explainable from the bottom-up. In other words, theoretically, once you’ve explained all of the physics for some event, there will be no remainder. Therefore, since our seemings are not identical to any physical states, whatever our seemings are, they must result from some underlying physical states and be epiphenomenal or causally inert. So, according to physicalism, there is no top-down causation where agents really choose anything. And, any seemings to the contrary isn’t to be trusted.
Now we get to the good parts. First, let us be clear on what constitutes an epiphenomenon. An epiphenomenon is one which occurs secondary to a primary phenomenon, a phenomenon which is caused, but causes not.
But this definition is unsatisfying. It simply instructs us in spotting epiphenomena and says nothing about their hows and whys. So how do epiphenomena arise and what are the relations which they have to regular, causal phenomena? Here are a couple of examples which demonstrate what I think those mechanisms and relations are.
First, consider that quintessential epiphenomenon: fever. Before medical science knew the details of the inflammatory response, fever was thought to cause illness. It was thought to be part of the pathological process. It turns out that fever is no such thing. Fever is a byproduct, the elevation of body temperature secondary to a particular biochemical process. So, fever is causally inert. Or is it? On an analytic basis, it is causally inert. Any ‘rules of fever’, for example ‘fever follows from infection’, are inaccurate and properly devolve to the rules of the primary process, which is the biochemistry of inflammation. But sometimes, the elevation of body temperature associated with inflammation inhibits bacterial and viral replication. Fever does something. What is going on here?
These are not the same fever. The fever which inhibits bacterial and viral replication does not give rise to rules nor does it itself participate in law-like relationships; the biochemistry of inflammation takes care of those things. But the biochemistry of inflammation does not, by its rules and law-like relationships, specify the causal relationship between elevation of body temperature and inhibition of bacterial and viral replication. If we started from the primary, biochemical phenomena we might never know about that causal relationship in particular. That’s fever’s job.
To clarify further, consider Hepatitis C. I don’t want to imply that the Hepatitis C virus is an epiphenomenon, ’cause it’s a virus. But the relationship that it might have held relative to the disease Hepatitis C by a certain theory of the disease, is an instructive analogy for the relationship which epipenomena have to their primary phenomena. Once upon a time, many scientists suspected that the Hepatitis C virus did not actually damage the cells in which it replicated. This turns out not quite to be the case, but it was a serious possibility, and let’s pretend for a moment that the theory was accurate. On an analytic basis, the Hep. C virus would be a non-entity. We could substitute “X provocative factor for inflammation” with no theoretical consequences. But Hep. C virus is precisely that provocative factor for those individuals infected with it, and in those cases the replicative habits and specific structure of the virus determine, in part, the natural history of the disease though the virus does not cause any of the pathology.
So, do fever and the non-cytopathic version of the Hep. C virus have causal efficacy? Are fever and Hepatitis C real things? Yes and no. Yes in the individual cases and no as generalities. Or rather, they pick out some real category of historical relations even though the theoretical causal analysis associated with fever and non-cytopathic Hep. C virus may ignore them. Inverting our perspective, cytokines, helper T-cells, etc. may tell us why John may have an elevation of his temperature – such explanations account for fever and even eliminate the need for the term in analysis – but the biochemical explanation of temperature elevation due to inflammation in response to viral infections cannot tell us all about why John has this temperature elevation due to inflammation. “John has a fever.” fills in the gap between the theory and the case, as the statement stands for the specific history of the virus, John’s genetics, his previous illnesses, his nutritional status; in short, all the messy data without which an account of John’s fever on November 10, 1999 at 10 AM via the theory of the primary phenomenon is impossible.
With this understanding of epiphenomena in hand, is physicalism committed to epiphenomenal consciousness? Yes and no, I think. Your patience please, for one more example.
There is a well known thought experiment proposed by the philosopher Frank Jackson called “Mary the Color Scientist”. In the thought experiment, Mary has been confined to a room without any color at all for her entire life. During her time in the colorless room, she has become obsessed with the neurophysiology of color perception and has managed to learn everything there is to know about the perception of the color red. One day, she is released from the room and thus confronted with all the colors of the outside world, including her first actual red perception. Does she say, “Wow!” or does she say, “Meh”? Does she gain any new knowledge via that perception?
Before we get to the final question, there is another question within the scenario. It has as a premise that physicalism requires, in principle, that Mary could know everything about red perception. For her knowledge to be complete, however, she must know much more than the neurophysical rules of red color perception. She must know all there is to know about the history leading up to her particular red perception. If physicalism’s view of events is assumed to be the case, all this knowing must happen in time and there is simply not enough, in principle.
“Sophistry!”, one may object, “She doesn’t have to know all that, just what makes for red perception right now, as she is first seeing red.”
Remember that little issue that Kevin mentioned in passing at the start: determinism? On physical determinism, all that is what constitutes red perception right now. An analytic theory of red, ‘averaged over’ red, however detailed, will not do. We want to know if there is a difference between knowing the reductive explanation of red and the perceptual experience of the same thing. To meet that requirement Mary must know the theory and the associated history which gives the theory its application. In such a case, Mary’s impression of red, as a thing in itself, stands for this otherwise inaccessible detail and so is a real thing just like fever – as a necessary part of the explanation of each case, and so as historical category as well. If the understanding of epiphenomena regarding fever and Hepatitis C extends to subjective experience, then even an epiphenomenal status for our seemings may be explicable in a physicalist framework, and avoid concerns of irrelevancy in the same ways.
However, I don’t think that our consciousness and its subjectivity are epiphenomenal because I don’t think our impressions are primary phenomena. Since we are playing pretend, let’s ignore physical determination and its implications, however improper that may be, and say Mary just does have the reductive explanation of exactly that red experience which is her first. I think she still says, “Wow!”. I think she gains the efficacious knowledge of red + Mary’s recourse to red references, or if we were to ask her, how red works. Red becomes an object of direct reference, where it was previously an object of reflection only. In fact, I think this is the basis of intention and awareness. Red’s ‘seeming’ on Mary’s first perception of it is Mary’s pre-red identity plus the actual, red sense-data compared to Mary’s pre-red identity including, most importantly, pre-red Mary’s expectation of post-red identity. Before her red perception, when Mary perceived an apple, she would first have to see the apple shape, depth to the shape, a stem, all of which brings “apple” to mind, and then reflect that the apple is also red. Her complete knowledge could not change that operational arrangement for her. After her red perception, red becomes available for Mary’s apple anticipations, and so her apple identifications directly, and subsequent apple viewings will give her an idea of ‘red like that apple’, and so on for the rest of her conscious life. I think this is a good description of what her basic conscious life is, if we want to distinguish it from unconscious processes like pupillary reactions to light. Without the momentary, non-reflective, anticipation-based integration of these alterations of identity, we have the zombies which are feared to plague physicalist explanations of mind – creatures with unmediated, locally contingent stimulus-response as their sole operational process. What the evolutionary consequences of such a distinction may be, I won’t guess, but the possibility of consequences addresses the concerns regarding potential invisibility to selection (misplaced though they are).