Does the thesis that the brain produces the mind cohere well with our overall background knowledge?
In the book The Myth of an Afterlife two of the authors Keith Augustine and Yonatan I. Fishman pen the following:
Of course, compared with a hypothesis that coheres well with our overall background knowledge, an “extraordinary” hypothesis at odds with our knowledge about how the world operates would generally be assigned a low prior probability. Accordingly, insofar as the independence thesis entails that a separable soul can perceive, think, feel, and deliberate apart from any biological basis at all (sometimes suggesting a stark break in our evolutionary connection to all other forms of life on earth), and apparently requires either that a nonphysical soul violates well-established physical laws by interacting with the brain, or else that the soul is itself a physical thing completely unknown to science, it is a highly extraordinary hypothesis that should be assigned a low prior probability. For the independence thesis to be more plausible than its antithesis on Bayesian grounds, we would need a considerable amount of compelling evidence in its favor—and at the expense of the dependence thesis—to outweigh its initially low prior probability. (page 260).
The independence thesis here refers to the notion that we survive our deaths in some form. Contrariwise, the dependence thesis refers to the notion that the mind and consciousness depend on the brain, hence they cannot exist without the brain. Here and elsewhere in the book (this is a huge book of 700+ pages with a total of 29 contributors all sporting impressive academic credentials), it is repeatedly hammered home ad nauseam -- and especially by Keith Augustine -- that the dependence thesis is consistent with the rest of our scientific knowledge of the world. And, conversely, the independence thesis is emphatically not.
Now, in order to claim this, consciousness must at least be potentially scientifically explicable. It is not sufficient to hold that consciousness simply appears as a brute fact once there is a certain level of physical complexity. We require a scientific explanation for how the brain produces consciousness, or we at least need to be confident that one will be eventually forthcoming.
But I have previously argued that it is not possible to provide such a scientific explanation for consciousness, at least not based on our current conception of science. I go into some detail as to why this is so in both my Science, the Afterlife, and theIntelligentsia (especially parts 4 and 5), and my Neither Modern Materialism nor Scienceas currently conceived can explain Consciousness (especially part 5). But, in a nutshell, I argue that because science limits itself to the quantifiable or that which can be measured, then it necessarily follows that it cannot in principle explain consciousness since the latter is essentially characterised by qualia (construed in its broadest sense) and intentionality (in its philosophical sense).
It is important to realise it is not only me that thinks there’s a problem here. The precise nature of the relationship of consciousness, or mind, to one's body, and more specifically how the brain can give rise to the mind, has been labelled the mind-body problem. There have been a variety of proposed solutions to this problem, but for each and every proposed solution there are dissenting voices questioning its intelligibility. And, to correct a possible misconception, although the overwhelming majority of scientists and philosophers adopt what they label as a materialist position, it’s not as if they’re all in agreement with each other – indeed far from it! There are many varieties of materialism and there is much disagreement as to which of the available varieties, if any, might be the correct one. Indeed, there are a small but increasing number of vocal philosophers and scientists who hold that no proposed materialist position can be argued to be adequate. If this is so, then how the mind relates to the brain is up in the air. Indeed, in recognition of the apparent irreconcilable nature of this relationship, and the problem of why the mind or consciousness exists at all, the philosopher David Chalmers has coined the phrase the hard problem.
Astonishingly The Myth of an Afterlife has very little to say about the mind/body problem. Where it is mentioned it is to attack dualism ( i.e the notion that the brain and mind are distinct, even if the former somehow gives rise to the latter). One will search this massive volume in vain for any mention of the well known difficulties for both materialism and for providing a scientific explanation of how the brain produces consciousness. Difficulties, as I make clear in my two essays, I regard as insurmountable; at least with our present conception of what comprises the material or physical. It is of little avail to stress the fact that mental capacities inevitably vary according to the intricacy and condition of one’s brain, if the intended conclusion -- that the latter produce the former -- cannot, in principle, be rendered scientifically explicable. Of course, undoubtedly the authors would not agree with arguments suggesting that the difficulties for providing a scientific explanation are insurmountable, or indeed that there are any difficulties in principle at all here. But such arguments should at least be addressed! They had over 700 pages to do so. Instead, much of this volume, and by differing authors, keeps repeating the same tired points over and over again -- namely the fact that mental states are altered by physical states of the brain. All well and good, but if the process whereby brain activity produces consciousness is wholly mysterious, if not effectively magical, then clearly one ought to be more open to alternative hypotheses.
2. Is it possible we could perceive, think, feel, and deliberate without a brain?
In responding to this, we should first of all remind ourselves that we have no idea, even in principle, how the brain all by itself could explain consciousness, and hence we have no idea of how the brain could 'perceive, think, feel, and deliberate' either. To that extent the possibility of there existing some sort of substantial self interacting with its brain, might provide that essential ingredient in some expanded physics. (See part 6 -- "The Mind-Brain Correlations" of my Neither Modern Materialism nor Science as currently conceived can explain Consciousness.) But perhaps even here such a self would require a brain? Does the fact that the brain is always implicated in our conscious experiences -- at least while we’re embodied -- entail that it plays a crucial role in the production of such experiences? Or does it at least make it extraordinary likely that it plays a crucial role in the production of such experiences?
Here we need to ask ourselves what the alternative is. Certainly, given the reality of the mind-brain correlations, then we should surely at a minimum acknowledge that the brain at least influences the abilities to perceive, think, feel, and deliberate, even if it does not produce them. A possibility that presents itself here is that such abilities might be innate to the self or soul, but that the brain serves to either facilitate or inhibit them. The brain, that is, might function in a roughly analogical manner to a type of reducing valve. So here our perceptions, thoughts, feelings and so on, could still be attributes of the soul, but while the soul operates through the brain, a dysfunctional brain could impair their manifestation where as a normal functioning brain allows their manifestation. To use an analogy employed by J. M. E. McTaggart:
If a man is shut up in a house, the transparency of the windows is an essential condition of his seeing the sky. But it would not be prudent to infer that, if he walked out of the house, he could not see the sky because there was no longer any glass through which he might see it. (Some Dogmas of Religion p105).
This view of the relationship of the self to its brain is sometimes referred to as the filter hypothesis. The authors do recognise this hypothesis but do not find it compelling. They say:
If the mind is “not generated by the brain but instead focused, limited, and constrained by it” (Kelly et al., 2007, p. xxx), the filter theory entails that a brainless mind will be expanded, less limited, and unrestricted by brain function. [This implies] that the greater the disruption in brain function, the “freer” the mind will be from its neural confines, and hence the clearer one’s cognitive function will be. For example,we would expect the progressive destruction of more and more of the brain’s “filter” by Alzheimer’s disease to progressively “free” more and more of consciousness, and thus increase Alzheimer’s patients’ mental proficiency as the disease progresses. (p230)
It's also worth mentioning that in rare instances one's mind does appear to improve alongside a dysfunctional brain; or at least the mind improves in some respects. The authors mention Alzheimer's disease. Pertinent here is a phenomenon called terminal lucidity that has been described by German biologist Michael Nahm as:
The (re-)emergence of normal or unusually enhanced mental abilities in dull, unconscious, or mentally ill patients shortly before death, including considerable elevation of mood and spiritual affectation, or the ability to speak in a previously unusual spiritualized and elated manner. (From here p89)
There's also hyperthymesia, the ability to remember practically everything that's ever happened to you. Hence a person afflicted by this condition has the ability to precisely recall what they were doing on a specific day that happened many years ago. And then there's acquired savant syndrome. In the link the author Darold A. Treffer describes this condition as 'instances [where] dormant savant skills emerge, sometimes at a prodigious level, after a brain injury or disease in previously non-disabled (neurotypical) persons where few such skills were evident before such CNS injury or disease'.
We currently lack an understanding of how such a self interacts with its brain, but, in stark contrast to any materialist position, I see no reason why the filter hypothesis might not be true. It does, after all, seem to be consistent with the fact that our mental capacities are normally impaired with brain damage, but on rare occasions are enhanced. On the other hand, reconciling any type of materialist position with these rare instances where mental capacity is enhanced, could be a challenge. Note that this is a challenge over and above the philosophical reasons for rejecting any type of materialist position I have articulated in my two essays.
It is to be conceded that this filter hypothesis does generate a whole host of questions. For one, why on earth does the self or soul operate through a brain in the first place? I do not profess to be able to give any answers as to why there should exist a physical reality at all, but given that one does, then it seems the self or soul operates through a brain to enable us to interact with this physical reality. In addition, I would speculate that it might be the case that part of the brain’s purpose is to filter out the perception of other realities, and conscious states, which might prove distracting in our ability to function proficiently within this physical reality. Hence, when our brains are in their normal functioning state, they might serve to normally prohibit such experiences like mystical experiences, near-death experiences, savant syndrome, hyperthymesia, experiences induced by psychedelic drugs, and so on and so forth. If this is correct, then such experiences are not a product of a disorganised, dysfunctional brain. Rather they are realities which exist out there that we are allowed a partial glimpse of due to our impaired ability of the brain to act as an effective “filter”.
3. Does the soul or self violate physical laws?
If we have a phenomenon that has been universally reported, we cannot assert it doesn't exist because it doesn't fit in with some pre-defined laws. Rather, a more encompassing theory needs to be advanced. A new theory, which while still explaining existing phenomena, is able to also accommodate this "anomalous" phenomenon.
In this context, I submit that we can be completely certain of the existence of at least one "anomalous" phenomenon, and that is our own consciousness. Moreover, I maintain that consciousness is necessarily causally efficacious as I argue here, and cannot be reduced to any physical processes as I argue in part 4 of my Science, the Afterlife, and the Intelligentsia. So a new more encompassing theory needs to be proposed. No flavour of reductive materialism accommodates these facts, although possibly some other mind-body position, but one that still holds the brains elicits/causes the mind, might. But what is certain is that current physical laws wholly leave out even our normal everyday embodied consciousness in their description of reality. It follows they cannot, therefore, be invoked to rule out consciousness surviving the demise of our bodies.