I want to make it clear at the outset that when I refer to consciousness, I’m primarily thinking about qualia in its broadest sense, in addition to the philosophical term intentionality. With this definition in mind, I’m personally convinced that neither science as currently conceived, nor modern materialism, can in principle explain consciousness. Although a few professional philosophers are of the same opinion as me about this, what is astounding is that the vast majority of professional philosophers and scientists, not only do not agree with this but, on the contrary, regard some type of materialism as being beyond any reasonable doubt. I intend in this essay to present their arguments as best as I am able to understand them. I will then show that these arguments simply do not measure up.
I should also add that I specifically have in mind modern materialism and science as currently conceived; namely the materialism and concept of science that have prevailed in the west since the birth of modern science in the 17th Century. However, to constantly append "modern" and "as currently conceived" would be unwieldy, so, for the sake of fluency, I shall simply use the words materialism and science in this essay.
1. First Argument for Materialism
William E Carroll tries to sum up the materialists position in the following quote:
[E]ither we explain the living in terms of material, mechanically operating constituents, or we explain it in terms of some mysterious spiritual substance, some vital force. There is no substitute to materialism but magic; for there is no philosophical position other than materialism that is compatible with modern science. This is true, so the argument goes, because this mysterious substance, this vital force, yields itself even in theory to no method of investigation; it must be cast aside, with the result that one is left with the inevitable conclusion that there is nothing more to living beings than their material parts. Either we have a dualist conception of nature—body separate from soul—or we have a materialist conception. Since science offers no evidence for the former, the latter must be true. (From here).
2. This first argument is question begging.
In my experience, the above quote more or less expresses the sentiments of the vast majority of professional scientists and philosophers. Indeed, it also expresses pretty much universally the sentiments of the many materialists who frequent skeptic discussion boards, facebook groups, and the like.
But there is an unexamined assumption being made here. Namely, that science is potentially able to describe reality in its entirety. So, although we do not have at present a full knowledge of all physical laws, we can nevertheless be confident that, once obtained, there is nothing that such physical laws could fail to explain.
We need to bear in mind, though, that science deals exclusively with that which can be measured, that is to say, it deals exclusively with the quantifiable aspects of reality. Materialism, at least in its modern form since the birth of the mechanistic philosophy in the 17th Century, holds that the material world is nothing but these measurable aspects of reality. Thus, this assumption that science completely describes reality equates to assuming modern philosophical materialism. But, this then makes science coextensive with materialism. Hence, the position that “there is no philosophical position other than materialism that is compatible with modern science” is true, not because it is some truth that has been discovered about the world, but rather it is rendered true purely by stipulation. And since any type of dualist position stands in opposition to materialism, then any type of dualism is also rendered false, by stipulation. A more transparent case of question begging you would be very hard-pressed to encounter!
3. Further arguments for Materialism
The above argument for materialism, though, can be strengthened in the following ways. First of all it has been pointed out that, since the birth of modern science in the 17th Century, science has been stunningly successful in furnishing us in with knowledge about the world, and has been an extraordinarily fruitful one in terms of the subsequent prediction and manipulation of our environment and in the creation of our technology. This strongly suggests that modern science pretty much accurately describes reality. It is silly, so materialists urge, to suppose there might be supernatural and spooky entities and influences -- such as souls, magic, spirits, demons and indeed even a non-physical consciousness -- which somehow escapes the steely gaze of science, and to achieve this by having no measurable influence on reality whatsoever! Why should we believe in the existence of the non-physical, which, by definition, our measuring instruments cannot detect?
Secondly, before science can even be able to get off the ground, certain essential suppositions have to be granted. One of these is that the very same physical laws apply throughout space and time. Surely another justifiable essential supposition is that science describes all of reality? Indeed, given the astonishing success of science, then why on earth should we imagine it could not?
Thirdly, it is often pointed out that consciousness only constitutes an extremely small part of the world. Science has explained almost everything else. Are we to suppose that this remaining, relatively minor phenomena, which has only existed for a vanishingly small part of the history of the Universe and is confined to planets which presumably will be very few and far between, is somehow immune to the relentlessness triumphant march of science?
4. Consciousness constitutes a unique problem
There is a glaring problem with these arguments for materialism. Here a quote by the physicist Stephen M. Barr is in order:
According to physics, every physical system is completely characterized—indeed, defined—by a set of “variables,” which mathematically describe what its elementary constituents are doing and whose evolution though time is governed by a set of mathematical rules and equations..I've also said something very similar to Barr. Talking about reductionism I say in science, the afterlife, and the intelligentsia:
[I]f one did know what all the variables were doing and the laws governing them, one could in principle derive everything there was to know about the system’s properties and behavior—if the system is just physical..
It is clear, however, that [such a reductive analysis] cannot be extended to consciousness. Even if one knew all the variables of a physical system, their values at one time or at all times, and the equations governing them, there would be no way to derive from that information anything about whether the system in question was conscious, was feeling anything, or was having subjective experiences of any sort (From here).
[B]y looking at the components of [a clockwork] clock - namely the cogs, the springs, and the wheels - and how they all interrelate together, we can actually understand how the hour and the minute hands move. Each cause and each effect in the causal chain(s) leading to the movement of the hands are wholly quantitative, something which can be measured.
The same pertains whenever we reach an understanding of some phenomenon. Consider tornadoes for example. They seem to be entities in their own right; they seem to act as organised wholes. But this cannot be an analogy for consciousness since it remains the case that tornadoes are nothing more than the movement and interactions of all the air and water molecules which constitute them. The number of parts constituting a tornado, and hence its complexity, doesn't allow it the possibility of producing anything beyond what a colossal number of particles are capable of producing, particularly not conscious experiences. So, similar to the clock, the tornado is the result of wholly quantitative processes and can be reductively explained.
But when we come to the brain and consciousness we have something very different. If the brain does indeed produce consciousness, then we have chains of quantitative causes and effects which at the end of these chains produce purely qualitative phenomena; namely conscious experiences. But then this contradicts the mechanistic philosophy since it stipulates that reality is wholly quantitative. And hence, consciousness also eludes any possible physical theory since physics deals exclusively with the quantitative or that which can be measured.
To try and explicate this fact yet further what we have is a chain of physical causes and effects following physical laws, and at the end a conscious experience such as the experience of pain. Unlike our clock or tornado, where we can always understand, at least in principle, how an effect is brought about by a thorough understanding of the arrangements and properties of their parts, we cannot have a similar understanding with consciousness. All we can note is that when certain physical events occur in the brain, this might be correlated with a certain characteristic experience -- an experience moreover which can only be known by the subject. Consciousness is not objectively detectable.
5. The Materialist's response and why this is unsatisfactory
The above arguments in part 4 seem quite definitive. However, the materialist does have an apparent solution. It is to identify consciousness with either physical processes or, alternatively, the causal role carried out by such processes. Assuming the latter pertains, all that which privately occurs in our heads -- that is all our thoughts, emotions, sensations and so on -- are regarded as being literally identical to what the brain does. Since science, at least in principle, can explain all the processes occurring in our brains, and since our consciousness is proposed to be identical to such processes, then we can explain consciousness. Problem solved.
But, of course, the problem is not solved one iota. In fact, there can be no argument made here. It is simply absurd. Indeed, I find it shocking that people -- and especially professional philosophers and scientists -- should voice support for such a transparent falsehood. One might, with somewhat more cogency, assert that plastic or rubber is really metal at bottom.
Let's be clear about this. Conscious experiences both exist and have a certain characteristic feel. Any experience I might have is private; it is only known through introspection, and no-one else fully knows what I am actually experiencing. The physical processes occurring in my head, on the other hand, are objective, they can be measured and consist purely of biological and electrochemical processes. Now, one might well contend that the latter somehow creates or elicits the former. But it is clear that they are not one and the very same thing. Indeed, they are wholly unlike each other!
Moreover, even if one were to disagree with me on this point and, by some unfathomable deep magic, the conflating of consciousness with the physical somehow could be made intelligible, why on earth should we take it seriously for one second? Of course, it’s the only option we have to make consciousness into a physical thing or process. But why suppose consciousness is physical at all? Why suppose that consciousness must be capable of being explained by science so that we are then forced to seriously propose that consciousness doesn't exist in its own right, but must really be identical to something else?
As we saw above in part 3, the answer to this is that science has been stunningly successful and, given this, it is reasonable to suppose science can potentially explain everything. Hence, anything which escapes detection by the methods of science -- such as a non-physical consciousness and other so-called "spooky stuff" -- can be assumed to be either illusory, so that in reality consciousness is something else apart from what it straightforwardly seems. Or, even more radically, to be assumed not to really exist at all.
But, this is absolutely no answer whatsoever. To borrow an analogy used by Edward Feser. It would be like someone concluding that because metal detectors are extraordinarily successful at detecting metal -- but never ever detect any objects made of plastic, or wood, or rubber, or indeed any other substance apart from metal -- then nothing but metal exists. Hence, anything which seems to be non-metallic is simply an illusion. You think you have a plastic object in your hand? Sorry, but my metal detector doesn't register it. Therefore, either it only seems to be made of plastic, but, in reality, it is metal, or it doesn't exist at all! And we might imagine them further saying, 'we cannot allow for the existence of spooky non-metal substances like plastic and rubber, otherwise how can we expect metal detectors to work at all? And besides our metal detectors are detecting ever smaller and smaller pieces of metal, thus vindicating our positio'.
But, in a similar way in which metal detectors are only designed to detect metal objects, and have nothing whatsoever to say about the existence, or otherwise, of objects made of other substances, so too are the methods of current science limited to the quantitative aspects of reality, and cannot have anything to say about aspects of reality not amenable to this approach. And it would be as silly to accuse people of being non-scientific when they point out that consciousness cannot in principle be explained by science, as it would be to accuse someone for being an anti-metallicist if they pointed out that metal detectors only detect metal and that other substances apart from metal exist.
Finally, the argument that science has explained almost everything else, and so probably will eventually be able to explain consciousness too, doesn’t pass muster either. To understand why, we have to bear in mind that the qualitative attributes of the external world -- namely colours, sounds and smells as we experience them -- are judged by the materialists not to really exist. Instead, they are identified with certain features of the physical world as described by physics. So colours are redefined to refer to a certain wavelength of light that objects reflect. Sounds are redefined to refer to rarefactions and compressions of the air. Smells are redefined to refer to molecules in motion. Thus, modern materialists advance a very much emaciated conception of the physical external world denuded of the flesh of the qualitative. A world devoid of colours, sounds, smells, as experienced. Moreover, this materialist conception of reality is not what they have discovered, rather it is one they have simply assumed in order to square the existence of the qualitative aspects of reality with what science can investigate (Just as it is likewise assumed that all that which privately occurs in our heads -- that is all our thoughts, emotions, sensations and so on -- are regarded as being literally identical to what the brain does).
If we reject this assumption and take seriously what our senses are telling us, so that we accept the physical world really does have colours, sounds and smells as we experience them, then it follows that science is limited to only being able to describe this emaciated conception of the physical external world denuded of the flesh of the qualitative. A far cry indeed from the claim that science has explained everything else apart from the mind.
6. The Mind-Brain Correlations
But what about the mind-brain correlations? How are they to be explained? Do they not justify materialism and provide a scientific explanation for consciousness?
The correlations are data. In order to make sense of that data, they need to be placed within the context of some scientific hypothesis which renders these correlations intelligible. There seems to me to be 4 possible hypotheses here.
i) The brain produces consciousness in much the same way as the internal components of a clock produce the movements of the clock’s hands. But we saw in section 4 that this is not a viable possibility.
ii) Consciousness is identical to some physical process. But, as I explain in section 5, this is not satisfactory either.
iii) We can still hold on to the view that the brain produces consciousness, but give up on the idea that consciousness can be reductively explained. It might be that certain physical processes -- perhaps due to their complexity – create conscious experiences as a simple brute fact that cannot be further analysed.
It is debatable whether this would constitute a genuine scientific hypothesis though since it denies that the most fundamental particles and/or fields that exist can actually explain consciousness. We have to be satisfied with additional non-reducible psychophysical laws linking specific brain states with specific mental states.
But this is deeply unsatisfactory. For what we are saying here is that physical processes, which wholly lack any qualitative features or intentionality, nevertheless, as a brute fact about the world, are accompanied by qualitative features and intentionality. This seems nothing short of miraculous. And given that the consciousness so produced can neither be derived nor is definable in quantitative terms, then it seems a stretch to label consciousness as material or physical, even if produced by the material.
And there are other problems. I’m sure we all have a very strong sense that we are literally the very same individuals throughout our lives. But our bodies, including our brains, are in a constant state of change and hence our mental states too. Indeed, compared to ourselves now, as children we had very different personality characteristics. So if the brain produces consciousness, how can we literally be the very same self throughout our lives? Or indeed, how can someone be literally the same person sober as when he is drunk given that his personality might change so much when drunk? It seems that we have to conclude that quite literally we are different selves throughout our lives (see my does the self as opposed to a mere "sense of self" exist? for more detail on this idea.)
Additionally, as I argue in A Causal Consciousness, Free Will, and Dualism, our consciousness necessarily has at least some causal efficacy. So (iii) would have to have consciousness in its turn affecting brain processes. I’m not sure if this is a problem or not, but it would be interactive dualism even though the brain produces consciousness. As such it wouldn’t curry much favour amongst the intelligentsia.
For all these reasons (iii) seems somewhat implausible, although, unlike (i) and (ii), it remains a possibility, albeit in my opinion an unlikely one.
iv) Which brings us to our final option. Namely, that there is something else involved. Consider a prism. The mixture of coloured lights obtained is not wholly produced by the prism all by itself. Something extra is involved; in this case, the white light which enters the prism. Or consider a TV set. The internal components do not produce the programmes. Similar to the prism something else is involved, namely TV signals. I submit that reason strongly suggests that this is the situation we have with the brain and consciousness. Similarly to these 2 examples something else, apart from the brain, must be involved. Some extra ingredient.
I would suggest that this extra ingredient is what we call the self or the experiencer. It is that which has conscious experiences; it is not identical to them. I (the self or experiencer) am not identical to either my thoughts, or my moods, or my interests, or all of them as a collective whole. To use the prism as an analogy. The mixture of coloured lights represents my current thoughts, moods, interests and more generally my present consciousness. But the white light stands for my self. And of course, necessarily it will be consistent with our intuitive conviction that we are literally the same self throughout our lives since this is the very entity we are stipulating must exist. Note too that, similarly to conscious experiences, this self is also not a physical thing or process. It is an extra ingredient apart from all the physical processes. Hence (iv) cannot be a materialist position – at least not materialism as currently conceived.
Nevertheless, despite not being a materialist position, I see no reason why science in some larger sense -- that is to say science that is not limited by our current conceptualisation of it -- could not in principle come up with a theory that explains this self and relates it to the physical world. We often are compelled to hypothesise additional entities in order to explain some phenomenon. Compare the way TV signals play a pivotal role in understanding where TV programmes come from. But since the self and its conscious states are non-material, it cannot be as science is currently conceived dealing as it currently does with merely the purely quantitative. It has to be a radically new theory that introduces consciousness and the self into the world as realities in themselves rather than being derived phenomena. Perhaps some interpretation of Quantum Mechanics might fulfil this role. But, if not, then some deeper physical theory will be required. Potentially such a theory will resolve all problems. It should, of course, explain how the self interacts with its brain and dispel any interaction problems such as causal closure. It will also be able to account for a causally efficacious self.
Any such theoretical interpretation would also tend to suggest that the self might well survive after the body dies. Since the self is not something which is material, and since the self is defined in terms of that which exists prior to the changes brought about by the brain (the white light and the TV signal rather than the mixture of coloured lights or the TV picture displayed), then this undermines the usual reasons to suppose the self cannot survive. A definitive answer to this survival question will presumably become obvious when such a satisfactory theory relating consciousness to the rest of reality is accomplished.
Of course, this self is in a very intimate association with the brain. Hence, should there be an afterlife, we should not expect to be exactly like we were just prior to death (thankfully so should we have been suffering from dementia!). Rather it is the self that survives (the white light in the case of the prism, and the TV signal in the case of the TV set). It is that which I have in common with myself as a child, or when drunk, and so on, that would survive.
Note that (iv) is not a desperate attempt to rescue the concept of an afterlife against the undeniable fact that our minds are hugely influenced by what is physically happening in our brains. Rather it is a position we are obliged to adopt since the only other viable alternative (iii) has some major detractions. So purely thinking about the mind-body problem, and taking no note whatsoever of all the evidence suggesting an afterlife, it might still seem a reasonable hypothesis that we survive.