Continued from Steve’s opening statement «
Steve begins his opening statement by describing the mind’s “place of residence” as the brain—an organ of such complexity that he believes it “functions to produce all the workings of the mind”. What is immediately obvious to me, though, is that complexity, in and of itself, is not really at issue. If complexity, qua complexity, were all that was required in a physical system to give rise to a mind, then Steve would surely be faced with some difficult questions about other systems which are not intelligent. For example, even if the human brain is the most complex self-contained physical system in the universe, it remains the the universe itself is a vastly more complex self-contained physical system. Does Steve contend that the universe, like us, is intelligent? If not, what is the distinction between us? What is it about the brain which gives rise to intelligence, when the universe—despite its greater complexity—remains unintelligent? Or, if Steve believes that the universe is intelligent, then what is it which is inherent in complexity itself which gives rise to intelligence? In order to establish his case, Steve really must establish the relationship between complexity and intelligence. To simply assert that some unexplained relationship exists is insufficient.
Steve then moves into a brief description of the distinction between objective and subjective facts. He explains how redness is not an inherent objective quality in substances which causes light to reflect at the wavelength we perceive as red. Unfortunately, this is both a misdirected and an insufficient argument. On the one hand, whether or not Aristotle thought that redness is an objective quality irrelevant to the fact that I do not. On the other hand, the fact remains that the qualia, the perceived sensation, of redness is indeed a subjective event for us. Describing the objective physical events and qualities which appear to cause the perception of redness does nothing to explain that subjective perception itself. So when Steve says that “some apparently universal ‘qualities’ seem to have been more resistant to explanation in material terms”, he is being a little disingenuous. Redness has not actually been explained in material terms either: it is just as resistant to explanation as the universal “qualities” under discussion. What has been explained is the physical characteristics associated with redness. Redness, a subjective perception, remains quite a mystery to naturalists—since science by definition is descriptive of objective facts; not subjective ones. That being said, Steve is correct to note that moral and propositional attitudes are not even explicable to science in terms of their objective properties in the way that redness is. There does not appear to be anything at all physical about goodness or truth in the way there is about redness or hotness.
Following this introduction, Steve argues that since all the other organs of the body—such as the heart and kidneys—require no “vital essence” or animating force, it follows that the brain has no similar kind of force. He claims that an argument for “mind-ism” is similar in nature to an argument for vitalism; and that since vitalism is clearly fallacious, mind-ism must be also. However, this argument fails on numerous counts. Firstly, Steve has a long way to go in establishing that vitalism even is fallacious. It is far from clear, for example, that there is nothing more to human life than the operations of various organic compounds organized in a certain way. Scientists are certainly not able to build a living human body from scratch. Steve may suppose that, in principle, this is simply a matter of technological limitations—but if I suppose differently there is really no way to be sure.
Secondly, mind-ism (from here on I shall call it by its proper name: dualism) is manifestly not similar to vitalism in the way Steve supposes. Life itself need not necessarily be defined by any non-physical characteristics. Although it often is defined in that way, a scientist might indeed state that life is “an organismic state characterized by capacity for metabolism, growth, reaction to stimuli, and reproduction” (Merriam-Webster Online, ‘life’). A plant may be alive without entailing an invocation of vitalism, for instance. And a Christian might even agree with this conclusion. The question that vitalism seeks to answer, in other words, is not necessarily one which cannot in principle be answered in purely physical, naturalistic terms. The question that dualism seeks to answer, however, is completely dissimilar. The very point under discussion, and the very argument that dualism makes, is that in principle there can be no cogent physical explanation for the mind. The reason dualism is forwarded as an explanation of the mind is precisely that a purely physical explanation is impossible by its very nature. If the mind can be reduced to physical events, then the very attributes which comprise it either cease to exist entirely, or become irrelevant to its functions. Things like intentionality and inference are either denied ontological existence at all in a naturalistic philosophy of mind, or become what philosophers call “epiphenomenal”—an incidental byproduct of physical events which actually have no causal involvement in what goes on.
This leads into the third point on which Steve’s argument fails: the assertion of mind/body causality. He says that “we know that minds are associated with brains, because of the causal connection between changes in brains and changes in minds.” He mentions brain injuries and genetic traits as examples of this causality. But as an armchair scientist, Steve ought to know that correlation between things does not entail causation; and, if causation is present, its direction or directions still must be established. So the fact that the brain and the mind are correlated does not necessarily entail a causal relationship. Furthermore, even if there is a causal relationship, it is tantamount to begging the question for Steve to assume that the direction of causation is only from the brain to the mind. Unless he assumes his own conclusion, he has no reason to dismiss the possibility that the mind may also causally affect the brain. We know, for example, that when people think of certain things, particular parts of their brains become active. But is that because the brain activity is causing the thoughts, or is it because the thoughts are causing the brain activity?
None of these concerns, though, are ultimately relevant. They do not address the issue at hand—the impossibility of human reason in a purely physical universe—and they never can. None of the additional points Steve raises as he builds his case are actually relevant to this question. The fact that neural networks can analyse certain signals and perform certain transformations on them, for example, does not pertain at all to the fact that reducing the mind to physical phenomena necessitates that we reduce logical inference, reasons, intentions, and decisions to physical phenomena as well—and thus remove their causal role as inference, reasons, intentions, and decisions from events which are clearly caused by these things. Similarly, the fact that the brain is an incredibly sophisticated information processor is really inconsequential to problem that the naturalist faces, that information is meaningful only subjectively, and not objectively. As Steve correctly recognizes, “the question relevant to this debate is whether the workings of a physical brain are sufficient to explain the experiences of a mind in terms of reasoning.” Unfortunately, his reason for believing that they are is simply a reiteration of the irrelevant details listed above, regarding the power of physical systems to perform certain tasks:
I believe they are, and the reason is evolution. Nervous systems evolve to control bodies. They have been selected to process information from the senses and from their internal states in order to help a body survive and reproduce. It is clear that this selection can result in the development of systems that can recognise some truths and usefully process them to obtain correct conclusions, as in Nature mistakes frequently lead to death. Much of this processing is automatic: a fish will catch a fly above a pond correcting for the distortion of light without understanding refraction. A bat will change the tone of its echo-location as it approaches an insect without an understanding of sonar.
In truth, it is really very far from clear that evolution could result in the development of systems which can recognize some truths and usefully process them to obtain correct conclusions. The fact that mistakes (that is, wrong conclusions) frequently lead to death does not mitigate this. For one thing, wrong conclusions don’t necessarily lead to death. For another, true conclusions don’t necessarily offer an evolutionary advantage. Alvin Plantinga has argued persuasively to this effect. However, even if we assume for the sake of argument that natural selection can be relied upon to often favor mechanisms which arrive at correct conclusions, and to often select against mechanisms which arrive at false ones, we are left with the problem of identifying which mechanisms and which conclusions these are. Since we are relying on the very mechanisms themselves to attempt this process of identification, we have to presuppose their reliability—but we have no actual justification for doing so since, if they are faulty, we might never know it.
Additionally, it is obvious that the kinds of conclusions that will be selected for might not have anything to do with the actual nature of things, because they are selected for based on their usefulness to survival, rather than for discovering truth. These are manifestly two completely different categories. Imagine, for example, a creature which evolved to consistently interpret round objects as being square. As long as interpreting roundness as squareness conveyed no particular disadvantage to the creature, how could it ever know that “square” things are actually round? Or, if this development did convey a survival disadvantage, what if interpreting round objects as ovoid was a sufficient evolutionary development to mitigate this disadvantage? Again, while closer to perceiving the actual nature of things, the creature is still in an epistemically hopeless position. How could it ever know that “ovoid” things are actually round? This is the position of any creature which is supposed to have evolved—including human beings. We can also extend this argument further: for even if it can be shown that evolution will select for generally true conclusions about physical reality, what relevance does this have to metaphysical questions? How does the ability to correctly identify a circle or a triangle imply the ability to correctly identify a logical fallacy or formulate a sound argument? What does modus tollens have to do with workable wheels; and what does the law of noncontradiction have to do with strong bridges? Evidently nothing at all. What reason is there, then, to think that faculties which developed to come to useful conclusions about physical, evolutionary pressures are in any way equipped to come to true conclusions about other things?
Having dealt with these problems, though, it is still clear that the argument Steve has forwarded has no explanatory power in terms of solving the main problem inherent in the naturalist philosophy of mind, and which constitutes the thrust of my argument. It is possible to assume everything that Steve has put on the table as true, and still refute him. This is made obvious by Steve himself—when he gets to the point of attempting to explain “why we have these feelings of intentionality and meaning”, he says that
This is because we mentally model minds; this is a necessary part of how we live as an intelligent ape. We need to consider what other people may or may not do, or what they may be thinking. And the natural way to consider that is in terms of what their intent might be, and what may be significant to them.
But it is painfully clear that the idea of “mentally modeling” what someone’s intent may be presupposes the concept of intentionality. It does not explain it—rather, it requires it. Additionally, some of the sorts of intentionality which Steve talks about here are very primitive. A tiger may “intend” to attack; but it is certainly not evident that it entertains the notion of attack in a way which entails the sort of propositional intentionality which we ourselves experience. But if propositional intentionality is not required in Steve’s argument to model other minds, then where did it come from in the first place? If we were once on the same level as tigers in terms of intelligence, what was it that caused this remarkable development, wherein propositional attitudes replaced simple primitive representation? Indeed, once again, there appears to be a chasm in principle between primitive representation and propositional intentionality. The one may be perhaps an entirely physical thing, as in the case of neural networks, and may result in a survival advantage. Yet the other is clearly something more, since it entails not merely physical representation, but mental interpretation. A shift has taken place from the objective to the subjective. A neural network does not have a subjective understanding of anything, for example. Steve needs to explain how our subjective perceptions developed from objective, physical events.
Steve once again correctly identifies that the “question is whether this mental processing implies what many say it does – that the propositional attributes have any reality, a reality which some imply requires the existence of a deity.” Unfortunately, he does not actually interact with either of these questions; choosing to instead merely reiterate again his belief that “without evidence to the contrary, all we have is the experience of truth and meaning when certain processing of information produces results that trigger (based on past experience and training of the mind) our mechanisms for detecting “truth” and “meaning” – just like we have the feeling of a colour when certain neuronal firing patterns occur.” The difficulty he faces is that the evidence to the contrary is now before him in my opening statement: the evidence is that his view is self-refuting, because without there being actual mental events called propositions, which lead to other actual mental events called conclusions, via actual mental laws called inference, Steve’s own argument would be impossible. We could not know it was true; indeed, to speak of it being “true” would be meaningless, since physical states of reality cannot be true or false. Yet that, indeed, is what Steve appears to be suggesting.