Preamble
The rally, or the last hurrah, which in recent years has been termed terminal lucidity, refers to where a person, typically suffering from dementia or some other neurological disorder, suddenly and seemingly miraculously reverts to their pre-dementia original selves. This usually occurs shortly before death. I recently read a book on this topic called Threshold: Terminal lucidity and the Border between Life and Death by Alexander Batthyány. I'll provide a summary of the salient points of this book followed by a few of my thoughts.
A summary of the book
According to Alexander Batthyány, states of intoxication and other induced exceptional psychological states pose a relatively weak argument against an enduring self or soul. This is for the simple reason that such conditions are temporary, and the original self soon returns. So, here, it cannot be the case that the original self was ever destroyed. The original self was there all along, but temporarily hidden.
It is seemingly very different with dementia. The progression of dementia appears to actually destroy a person's beliefs, interests, memories, and very character. This, in turn, also implies that normal brains cause our usual standard personality and character. If these suppositions are correct, what can be left of any eternal, immutable soul?
However, terminal lucidity has now demonstrated that the original self can return. This is, to say the least, perplexing since, at least with dementia, the damage to the brain is still there. How is it possible to have a normal, clear, lucid mind with a severely diseased brain if the brain produces consciousness? Indeed, it doesn't seem possible.
The author draws parallels between terminal lucidity and Near-Death Experiences (NDEs). In NDEs, we also have self-consciousness and personhood when these ought to be highly unlikely given the impaired brain states. So despite compromised brain activity during both terminal lucidity and NDEs, individuals have normal if not enhanced mental alertness, vision, and memories. As an aside, whilst the author doesn't mention this, one might wonder about a potential connection to savant syndrome here?
The author posits that both terminal lucidity and NDE's strongly imply that it cannot be the brain, or indeed the whole body, that somehow produces consciousness. And yet, on the other hand, the author also feels this is strongly contradicted by all the other overwhelming evidence that appears to show that consciousness, or the mind, is very much dependent on the proper functioning of one's brain.
The author tries to reconcile what terminal lucidity and NDE's seem to imply with this contrary evidence, by employing two analogies. The first one is that the mind-brain relationship resembles a total solar eclipse. During such an eclipse, we cannot see the sun, we can only see the coronal filaments peeping out from behind the moon. If we did not know better, we would fallaciously infer the moon somehow produces these filaments. Similarly, we fallaciously infer the brain produces consciousness. The other analogy is the mind at large idea. This holds that the brain functions similarly to a “reducing valve”, which filters out a much greater and expanded consciousness to prevent us from being overwhelmed and confused by a vast ocean of conscious experiences.
My Thoughts
The idea that we simply cease to exist when we die derives much of its plausibility from the supposition that as someone approaches death, their consciousness will gradually diminish until finally reaching zero. However, episodes of terminal lucidity and NDEs show that this does not always occur. Indeed, NDErs, despite being on the threshold of death, frequently report that they felt more conscious than they had ever felt when alive. So it seems to me that both terminal lucidity and NDEs — as well as other anomalous phenomena near death such as deathbed visions, crisis apparitions, and shared death experiences — strongly challenge the idea that consciousness is solely produced by the brain.
On the other hand, apparently contradicting this evidence is the undeniable fact that a damaged brain usually leads to a damaged mind. Do the total solar eclipse and the mind at large analogies explain how a soul could exist in the face of all this contrary evidence?
To address the full solar eclipse analogy first. To reiterate, the message is that in a total solar eclipse, just as one might erroneously suppose the moon somehow produces the coronal filaments peeping out from behind the moon, so we erroneously assume the brain is producing consciousness. We need to remind ourselves, though, that brain damage adversely impacts our actual minds as experienced by that person himself. It's not clear to me how the analogy actually addresses this.
What about the mind at large hypothesis where the brain functions as something akin to a reducing valve? I think this is a better analogy, and indeed I have a lot of sympathy for it. However, this has concerns too. For example, Keith Augustine and Yonatan I. Fishman in The Myth of an Afterlife in a chapter called, The Dualist's Dilemma, argue against this “filter” hypothesis when they say:
[W]e 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.
Of course, with terminal lucidity, some Alzheimer’s patients' mental proficiency is indeed increased (which they do not mention), but this is the exception rather than the norm. So the mind at large hypothesis needs to be fleshed out a bit to address this criticism.
I have thought of a simpler analogy, one that avoids such criticisms. Consider the fact that whilst a person has on a pair of eyeglasses their vision will be influenced by the state of the lenses, mostly (but not always) for the worse. For example, the lenses might fog up, or acquire scratches over time, both of which will compromise that person's vision. Yet if they were to take off their eyeglasses, then their vision would be restored to what it was originally.
So whilst wearing eyeglasses, the more badly damaged the lenses are, the worse our vision will get. Notwithstanding this, neither the lenses nor the eyeglasses as a whole, produce our vision. Moreover, there is no conceivable mechanism whereby the lenses, or the eyeglasses as a whole, could actually produce our vision.
The same pertains to the mind and brain. We have a correlation between damage to the brain and how much the mind is impaired, yet there is no conceivable mechanism whereby the brain could produce consciousness. Indeed, this is why we have the hard problem*. So, just as eyeglasses merely affect vision, it seems reasonable from just philosophical grounds alone to suppose brains merely affect (not produce) our mind states. So while the mind, or self/soul is embodied, it will operate through the brain and therefore will be subject to any damage that the brain may acquire. Yet the soul, which is the analogical equivalent to unaided sight in the eyeglasses analogy, remains the same throughout. And this interpretation is bolstered when we take into account all the evidence suggesting an afterlife.
But what about terminal lucidity? I think the eyeglasses analogy covers this too. Consider if both lenses of a pair of eyeglasses get cracked and badly splintered, and a hole develops in one of the lenses through which a person wearing the eyeglasses can see. Perhaps something analogically akin is happening in terminal lucidity — namely, a damaged brain allows the soul to partially bypass it and attain the state of consciousness and cognitive abilities that it would have when disembodied.
In conclusion, I appreciate this book for its potential to both bring terminal lucidity to the wider public's attention and to convey that it is very difficult, if not impossible, to square this phenomenon with the notion that the brain somehow produces the mind. I'm not sure, though, that the author has made it sufficiently clear that the brain merely affecting consciousness is not only a viable alternative but is actually somewhat more plausible than the mainstream position that the brain produces the mind. However, notwithstanding the book's detractions, it's certainly well worth reading.
*This, incidentally, is why many academics prefer to hypothesize that the mind is quite literally the same as brain processes, or it's literally what the brain does i.e. they favour some type of reductive materialism. However, physical processes and conscious experiences are wholly unlike each other, even if the former somehow causes or elicits the latter. So it seems to me that reductive materialism is definitively ruled out.