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Tallis in Wonderland
The How & Why of Consciousness
Raymond Tallis says the mysteries haven’t been solved.
Of the many mysteries in which our existence is wrapped, three seem especially resistant to being transformed into soluble problems: why there is something rather than nothing (the origin of stuff); how the material world gave rise to organisms (the origin of living stuff); and how organic life came to be aware of itself and its surroundings (the origin of conscious stuff).
Physicists, who routinely go, even dance, where others fear to tread, sometimes imagine they have an answer to the first mystery. According to Lawrence Krauss in A Universe from Nothing (2012), the universe may have arisen out of nothing in virtue of an instability in the quantum vacuum that somehow delivers a preponderance of stuff over anti-stuff. This seems closer to creative accounting than a plausible creation story.
As for the second mystery – the emergence of living stuff in a dead world – a succession of theories, and numerous experiments replicating the conditions prevailing when life is thought to have begun, have brought us no closer to a coherent story of the origin of organisms. Yes, we can propose plausible mechanisms as to how molecules associated with life, such as carbohydrates, nucleic acids, and proteins, might have arisen. What is not at all clear is how these could have generated the dialectic between relatively stable structures and the interactions necessary to maintain those structures seen in the most elementary organisms. (For a discussion of this, see my piece ‘The Soup and the Scaffolding’, Philosophy Now, Issue 83.)
For some philosophers, the third mystery – the origin of consciousness – seems closer to solubility. The solution, we are assured, is to be found in evolutionary theory. Consciousness gives organisms an advantage, and more or better consciousness gives them greater advantage. So the passage from the first twinkle of sentience to the rich and complex awareness of subscribers to Philosophy Now can be explained by natural selection acting on spontaneous variation favouring the survival of mutations that are more conscious than the competition.
Start Making Sense
There are at least two problems with this putative explanation of the emergence of consciousness: the ‘How?’ question of the origin of sentience (that is, of the experience of sensations) in the first place; and the ‘Why?’ question regarding the advantages that are supposed to come with being conscious, and the greater advantages that higher levels of consciousness confer. I shall deal with the ‘How?’ question presently. I want first to address what seems like a no-brainer: the advantage of being a conscious organism rather than a self-replicating bag of chemicals innocent of its own existence.
It is important not to start near the end of the story, with complex, sophisticated organisms such as higher mammals. Creatures of this kind clearly rely on being conscious of their environments for locating food and water, identifying mates, avoiding predators, and rearing their young. If your life depends on conscious navigation through the world, it is a good idea to remain conscious. If I lose consciousness, and there’s no-one else to take over my care, I am doomed.
But to begin with creatures like us is to start in the wrong place. Many of the faculties people cite in response to the ‘Why consciousness?’ question emerge only after consciousness has evolved to such a high level of sophistication, allowing, for example, the conscious entertainment of (explicit, bespoke) possibilities, which will fine-tune responses to situations; selective, voluntary attention; and motivation (as when bodily events are experienced as painful or pleasurable.) No. We must begin at the beginning: by asking, for example, what survival value is conferred on a photosensitive cell in virtue of its organism being aware of the light incident upon it. And the answer appears to be: ‘none’. This is equally the case with more complex organisms. Would a tree be more likely to flourish if it were aware of the light incident upon its leaves? The unbreakable habits of the physical world that connect processes in a photosensitive cell with events promoting the survival and functioning of an organism would not be tilted more in the organism’s favour if the latter were conscious of that light. Indeed, the highly improbable but entirely physically law-abiding nonconscious processes that led ultimately to the generation of that cell must dovetail perfectly with the physical processes necessary to keep it going long enough to replicate. Generation and survival must be both equally aligned with the grain of the insentient material world.
If there’s no reason to believe that the sentience of primitive organisms would give them an edge over the competition, there is no starting point for the evolutionary journey to the sophisticated consciousness we see in higher organisms like you and me; no basis for the assumption that making processes within and around the organism explicit to it will enhance the ability of that organism to manipulate them to its advantage. After all, the most successful organisms, in terms both of species endurance and of influence on the planet, are the nonconscious cyanobacteria, which have been around for 2.5 billion years. This is a striking challenge to claims about the evolutionary benefits of consciousness - and, indeed, to the criteria of evolutionary success by which we judge the benefits associated with this or that variation.
Of course, being conscious at a higher level brings with it apparent advantages. This is obvious in the case of action at a temporal distance from a goal, guided by anticipated possibilities informed by experiences made explicit through being recalled, or in other words, being able to think ahead. Stan Klein has argued for the advantage of “freeing the organism from its neural mooring and positioning it within phenomenal space outside of the brain” (‘Going Out of My Head: An Evolutionary Proposal Concerning the “Why” of Sentience’, Stan Klein et al, Psychology of Consciousness: Theory, Research, and Practice, forthcoming). This ability to consider the wider world may well be advantageous; but we may also reasonably assume that it appeared a long time after the appearance of the first sentient organisms, and evolutionary processes cannot rely on deferred benefits.
The same counterargument applies to other benefits ascribed to higher levels of consciousness. Complex sensory (‘phenomenal’) experience may, for example, be a prompt for recreational activity – by which I mean activity that goes beyond useful activity narrowly construed. Yet such explorations may ultimately deliver extra functional rewards – new skills, new technology. It is therefore no coincidence that Homo ludens (‘playful humanity’) is Homo faber (‘humanity the maker’). This has been suggested by Axel Cleeremans and Catherine Tallon-Baudrey:
“Under our hypothesis, consciousness would have evolved and been selected because it adds an important degree of freedom to the machinery of reward-based behaviour: behaviour that seems purposeless from a purely functional perspective nevertheless has intrinsic value.”
(‘Consciousness matters: phenomenal experience has functional value’, Neuroscience of Consciousness, (1) 1-11, 2022.)
But even if this kind of sophistication came packaged with the first smidgeon of sentience – and manifestly it doesn’t – it is still not clear that responses to the environment would be more useful, giving the sentient organism an edge over its insentient competition, if it is made explicit by being experienced as being ‘out there’. The possibility of getting things right brings with it the possibility of getting them wrong. While natural selection may favour those organisms that get things right more often than they get things wrong, it is not clear that sometimes getting things right and sometimes getting them wrong, sometimes correctly judging, and sometimes misjudging, will overall give the organism an advantage over organisms that mechanically respond to the natural world. Mechanisms expressing the unshakeable uniformities of nature cannot make mistakes.
What’s more, any benefits that come with consciousness are very costly, if one believes in a biological account of consciousness. Nervous systems are metabolically very greedy, and require a good deal of protection. And in the case of exotic megafauna such as us, the longer life expectancy associated with consciousness requires a vast and complex support system beyond the brain. Importantly, none of this was available at the beginning of life, nor in the first several billion years or so of evolution. Full-blown agency (greatly magnified by the collectivisation of consciousness as seen in human beings) arrived very late in the biosphere, possibly only with the higher mammals. The most plausible advantages of consciousness – still not entirely plausible – are found only in organisms that have emerged recently in the evolutionary story.
Galaxy brain female © Jon Manning 2021 Public Domain
When we reflect on what is made possible by consciousness, we tend to overlook what is achieved in the absence of consciousness. Unconscious mechanism was sufficient to deliver the long and tortuous passage from lifeless chemicals to conscious organisms. Nothing in our portfolio of voluntary actions can compare with what is achieved through the processes that have synthesised us out of those zygotes from which our intra-uterine journey to the howling, nappy-filling apple of our parents’ eyes began. Moreover, if we had consciously to do most of the things that make our continuing life possible (breathe, keep our hearts beating, etc), we would not survive beyond the moment of our birth. In short, what is delivered by nonconscious happenings makes conscious agency seem small beer.
It is therefore far from obvious that consciousness would have survived beyond its probable beginnings as unicellular sentience on the grounds of any advantage it might confer on an organism. Even if any explanation of the ‘why’ of consciousness withstood scrutiny, the ‘how’ would remain unexplained. None of the evolutionary mechanisms invoked to explain the increasing complexity and versatility of living creatures – accounting for the passage from micro-organisms to primates by natural selection operating on spontaneous variation – tells us how living tissue acquired consciousness, and, in the case of some creatures (you), a sophisticated self-consciousness. So even if consciousness did confer an advantage from its very beginning as micro-twinkles of sentience, it is not clear how those twinkles could emerge from insentient matter. The ‘Why’ of evolutionary advantage would not deliver the ‘How’. Natural selection can operate only on what is already available. Evolutionary processes that lead from simple, unicellular organisms to exotic megafauna are in theory understandable in physical, chemical, biochemical, and biological terms. Those that lead from insentience to sentience, and from sentience to sophisticated consciousness, cannot be understood in this way. So while it may be handy to have sophisticated consciousness, this handiness is not an explanation of its emergence. After all, there are other faculties that would be even more handy – such as the capacity for an organism faced with a predator to dematerialize, then rematerialize a kilometre away. The theory of evolution goes some way towards delivering the ‘Why’ of the emergence of certain novel features of organisms during the 3.5 billion years that have passed since life first appeared on Earth. Comparative advantage in the competition with other species and conspecifics does not, however, account for either the ‘Why’ or the ‘How’ of the emergence of consciousness.
The three mysteries of our existence remain intact.
© Prof. Raymond Tallis 2023
Raymond Tallis’s latest book, Prague 22: A Philosopher Takes a Tram Through a City will be published in conjunction with Philosophy Now in early 2024.