Steve Arnott continues his series of articles on Darwinism and Marxism with a look at what neuroscience tells us about how the ultimate evolved organ so far known in nature – the human brain – achieves consciousness.
In previous issues of The Point I have outlined the basic case for the left abandoning its traditional knee jerk hostility to biological evolutionary based accounts of human nature, and argued that the scientific evidence overwhelmingly shows that the terms of the old nature versus nurture debate are redundant. A modern Theory of Persons must note that both what is given to human nature through evolution and the expression of genes and what is given to us by our personal histories in the world, our environment, our social interactions and culture are wholly necessary for the full and diverse expression of our personalities, consciousness and humanity. Further, I argued that far from weakening the ideas of socialism, such a view strengthens the case for a progressive, liberal, socially and economically just society.
Secondly, I explored the connection between game theory and the work of Robert Axelrod, Robert Trivers, William Hamilton and others - ideas outlined in Matt Ridley's The Origins of Virtue and Richard Dawkins The Selfish Gene - and argued that the left needs to outgrow its shameful and wilful misinterpretation of this work as a) biological determinism and b) providing ideological cover for free market capitalism with the idea that 'human nature' is inherently selfish. In actuality, this body of work is about understanding the evolutionary bases of altruistic and co-operative behaviour in species and, if anything, shows the adaptive power of co-operation and social organisation. Human beings are capable of selfishness, but they are also capable of working together in solidarity for common goals and purposes. The weight of evidence shows that there is no scientific reason why a socialist society could not work provided that socialist society understood and acted upon a genuinely scientific understanding of human nature.
In two articles in The point's predecessor publication, the Democratic Green Socialist, my colleague Gary Fraser, basing himself on the work of Steven Pinker and others has outlined why 'the blank slate' view of human consciousness, adopted from enlightenment liberalism by both Marxist Leninists and modern social constructivists, is scientifically untenable and has damaged the cause of socialism throughout the 20th century and the early decade of the 21st, outlining some of the confusions, paradoxes and downright absurdities such a position leads to, and arguing for a new and progressive socialist politics based on evolutionary psychology and a proper scientific understanding of human consciousness.
These articles, 'The Left and the Denial of Human Nature' parts 1 and 2 we hope to republish here in The Point at some future date.
It is clear that a small group of writers and thinkers based around The Point magazine have begun to challenge many of the accepted shibboleths of the left and to promote the beginnings of a new synthesis between evolutionary thinking and the sphere of civil society and left politics through a pro-science, pro-rationalist approach.
I have referred to this as Darwinist-Marxism, though others may see that as too prescriptive or even too ambitious. Other phrases I have used are A Theory of Persons, and for the purposes of a catchy but appropriate title for this long series of essays, which may become a book, I have borrowed Professor Dawkins poetic phrase The Conspiracy of Doves.
What is necessary now is to put some 'meat on the bones' of this developing worldview. Though I seek no monopoly on the discussion and development of this work, and indeed, will encourage others convinced of its core truths to write and develop ideas and aspects of their own in relation to blank slate-ism, evolutionary psychology, and their relationship to contemporary or historical political debates and so on, over my next three or so contributions or so it will fall on me to begin to make good on some of my promises in outline I made when I embarked on this project back in issue 4 of this magazine.
A little further down the line I need to show why the fundamental ideas of Marx are scientific and universally relevant – not simply by virtue of repeated assertion of the fact by vanguardist committees, or even in the terms Marx and Engels themselves posed the question - but in the narrower and more rigourous terms of the key and broadly accepted definitions of scientific activity and postulates from the philosophy of science, including in terms of Karl Popper's idea of 'falsifiability'. I will also want to develop the idea that Leninist 'blank-slate-ism' was a tragic departure from Marx's more rounded view that human beings possessed both social and species being. As with all of these 'heretical' ideas I expect such an article to be controversial. Research is under way and I hope to post an article or articles covering these matters on the The Point sometime over the next year.
Beginning with the Brain
Firstly, however, in order to lay the ground for a synthesis between Darwinism, Marxism and a scientific theory of human nature and consciousness, it will be desirable to equip the reader interested in these ideas with a basic understanding of the best available dialectical and materialist theory of human consciousness; of how the remarkable, rich and differentiated phenomena of consciousness arises in nature from the human brain. Although we have previously critiqued simplistic leftist views of human nature, blank slate-ism and so on, and emphasised how human personal and social consciousness can only arise through both nature and nurture acting in dialectical concert, it is not enough, I wager, to simply deal with those generalities – important as they are.
The reader will be better placed to understand the whole from a philosophical and political perspective with a decent lay comprehension of the multifarious and multiply connected physical processes that make consciousness possible – that make you and the process that is you possible, and that in turn make the social interaction that is us possible. To do so we shall have to touch on neuroscience. Specifically, in this chapter and the next, I want to outline in a little detail the best and most experimentally robust theory we have of how consciousness arises from the grey matter of the brain. This is the theory of neuronal group selection (TNGS) or Neural Darwinism, as postulated by Nobel prize winning immunologist, Director of the Neurosciences Institute and President of the Neurosciences Research Foundation, Gerald Edelman, and his co-worker Giulio Tononi.
Edelman – A controversial genius?
Gerald Edelman did not start his professional life as a neuro-scientist, but as an immunologist. Had he not turned his interest to the science of how our brains work, and how the matter of our brains gives rise to the unique and multi-layered thing we called consciousness, he would still have secured his place in the scientific pantheon for his work on how the human immune system – and by evolutionary implication – all animal immune systems worked.
He shared the Nobel Prize for Physiology and Medicine in 1972 with Rodney Robert Porter for a fundamental and important discovery on how the immune system operated that ran contrary to previous models in a counter intuitive and surprising way. Previously it had been thought that anti-bodies operated like a cellular 'magic putty', moulding themselves in some way to fit round the molecules of invader viruses and therefore neutralise them. Indeed, this is probably still the 'folk wisdom' picture that most people have in their heads of how their immune system works when they get a cold or some other virus. Edelman dubbed this an 'instructional' model of immunology – the attacking virus carries information about itself which then instructs the antibodies towards a match.
What Edelman and his co-workers showed contrary to this picture was that the body constantly produces and has at its disposal a plethora – a reserve army – of antibodies with a wide range of molecular fits (which it carries as a result of multi-generational evolutionary adaptation), and that when a virus invades the body the closest match of antibody will massively increase in number according to its ability to neutralise the invading virus. This model Edelman described as a 'selectional' or Darwinian system, by which he meant that it was much closer to the model of population thinking and selection for adaptive traits by environmental selection than any instructional or information based theory.
It was this fundamental insight – that there could be important aspects of human biological processes existing in somatic (body) time that could be best understood as evolution mirroring itself i.e. as selectional, adaptive processes that themselves had been selected for over evolutionary timescales – that Edelman carried with him into his work and second career as a neuro-scientist.
Until relatively recently, although certain aspects of brain function had been well mapped out and a functioning neuro-anatomical model of the brain existed, what gave rise to those functions and how the different areas of the brain worked together to produce consciousness was not well understood. The 'problem of consciousness',
how the 'mere' matter of our gray squidgy wet seven pounds of brain can give rise to all the differential and rich experiences that we all have subjectively and individually and refer to collectively and objectively as consciousness, was regarded by many as intractable.
In philosophy, 'central state' materialists argued that the brain was, of course, the mind, and that no consciousness could exist without brain activity – but no coherent biological theory of how the brain did this was offered as part of the package. A few retreated into some sort of unspoken Cartesian dualism (what Nietzche bluntly called 'the soul superstition'). Others put forward the concept of epiphenomenalism – the ridiculous idea that conscious experience is merely a by-product of the hidden workings of the brain. One physicist, Roger Penrose, even wrote two lengthy books full of Godelian mathematics arguing that consciousness could only be understood when we had a complete theory of quantum gravity. How quantum gravity – presumably a universal constant – could produce self awareness, intelligence, and mathematics in human beings but not in trout or wombats or mice was not explained. (You may disagree on the question of mice if you are a fan of Hitchhiker's Guide to the Galaxy.)
The most popular model of the brain in philosophy of mind and artificial intelligence studies at the time I was doing my undergraduate thesis on the subject – and co-incidentally when Edelman's work on the subject was just coming to wider non-specialist attention – was the functionalist or computational model of intelligence/the brain/consciousness (the three are sometimes but not always interchangeable in the literature).
In this view, slow but steady progress could be made in understanding the operation of consciousness by breaking it down into its various functions – seeing, interpreting, hearing, responding to environmental stimuli and so on, and then trying to work out how such processes could be understood and perhaps replicated or simulated computationally. It would be wrong to suggest this approach has been completely fruitless. Breakthroughs – slow and steady, right enough - have been made in the field of artificial or simulated intelligence. We now have machines that can replicate aspects of intelligent behaviour, and in some aspects far exceed it.
No-one, however, is suggesting that Asimo, the robot, or Deep Blue, the chess playing computer actually are intelligent in the same we are, or are in any way conscious or aware. They are machines. Their simulation of aspects of behaviour or intelligence results from their clever mathematical programming by human beings. Remove that and they are simply inert objects. Further, it is clearly easier to simulate certain aspects of intelligence than others. Some processes lend themselves easily to a computational model and others do not. A program to read and manipulate pixels on a screen or deliver guided missile to its target is 'clever' but relatively easy to devise. No-one has yet produced a robot clever enough to ride a bicycle around an obstacle course, paint an original picture, or bake a cake in any kitchen in the world it found itself, let alone fool someone face to face that it is a human being in a Turing test.
Into this dominant functionalist/computational model strode Gerald Edelman (some – cruelly and wrongly, in my view - might say blundered, rather than strode). Edelman, who by now was a well established neuroscientist, with decades of work and experimentation behind him and who had published three well received specialist academic books outlining his brain theories – Neural Darwinism, Topobiology and The Remembered Present – argued that the brain did not work like a computer, and that attempts to model or understand the material bases of consciousness on the basis of the functionalist/computational model were doomed to failure or, at the very least, severe limitation.
Edelman argued that the brain did not operate on a computational or 'instructional' basis. The environment was not simply computer tape processed by the brain and then 'read' and responded to on a pre-programmed basis. In any case, who or what was doing the 'reading' or the 'programming'? Who or what created the self-awareness of conscious acts? In the absence of a traditional programmer we were back to a sort of dualism, where consciousness could not be explained by the complexity and organisation of the matter itself, but required 'spook stuff' or a homunculus, or even an infinite regression of homunculi seated somewhere in the brain. Further, methodologically, Edelman could not comprehend why philosophers of mind, artificial intelligence scientists and others did not take as their empirical starting point the one example of a substrate of sophisticated consciousness and self awareness that we know exists and functions – the biology of the human brain.
"What is it these scholars are missing, and why is it critical?
They are missing the idea that a description of the mind cannot proceed "liberally" – that is, in the absence of a detailed biological description of the brain. They are disregarding a large body of evidence that undermines the view that the brain is a kind of computer. They are ignoring evidence showing that the way in which the categorisation of objects and events occurs in animals and in humans does not at all resemble logic or computation. And they are confusing the formal power of physics as created by human observers with the presumption that the power of physics can deal with biological systems that have evolved in historical ways."
- Gerald Edelman, Bright Air, Brilliant Fire
Fundamentals of TNGS
As one might guess from the name of Edelman's theory – neuronal group selection – Edelman and his supporters posit that the brain, like the immune system and evolution by natural selection is a selectional system.
TNGS argues fundamentally that the brain is a selectional system at multiple interlocking and dynamically linked levels.
Firstly, that the gross anatomy and potentialities of the brain have been selected for over evolutionary time scales, and that consciousness in all of its richness and functions can only be understood if first and foremost we consider it as having adaptive power in relation to the survival and prospering of the organism in which it is embodied.
Secondly, that our genes code for the development of the morphology of our brains both during embryonic development, and, post birth, in response to our environment as individuals with unique histories; certain individual neuronal cells and groups have the capability to move, extend and develop within the brain topobiologically (topos meaning place); this dynamic development is both made possible, and constrained, by both our genetic inheritance and the natural morphological limits the expression of such genes gives rise to.
Thirdly, the brain itself, through a system of re-entrant mapping linked to evolutionarily determined value systems distinguishes salient events for the organism, - such as, for instance, successfully locating a mother's teat, distinguishing between sounds and sights, or responding to danger. Specifically, in relation to humans, it is involved in an infant pushing the right button to get its toddler's toy to make a pleasing noise, or lifting a cup successfully, after some near misses, in order to drink, and later, learning to ride a bike, build a wall, select the right gear while driving, or compose a symphony. This system selects, in somatic (body) time, neuronal groups which are successful in firing and linking with other neuronal groups in such a way as to produce an optimal survival/adaptive based response to stimuli. This constantly ongoing process in response to our environment produces multiple contemporaneous firing of neuronal groups selected for specific functions across the brain and leads to the adaptive ability to perceive or construct a scene.
This concept of re-entrant mapping is probably the single most important pillar on which the theory of neuronal group selection rests. It is these multiply connected and recursive extended connections between neuronal groups in multiple areas of the brain and across multiple brain functions that ultimately allow contemporaneous and co-ordinated neuronal response to sapient events in the environment of the organism and 'classify' them according to the adaptive and survival value for the organism. Importantly, because these neuronal selections take place in body time and in response to an individuated environment these are not only general species based responses to salient value, but are qualitatively developed, as a person develops, into individual characteristics and historical preferences that are of adaptive value to the individual. Edelman and Tononi write:
If we consider the combinatorial possibilities for re-entrant selection across (the brain), even after allowing a number of neuro-anatomical constraints to operate, we begin to glimpse the remarkable power of neuroanatomy in a selectional system. A jungle or food web, like the brain, has many levels and routes for the passage of signals but has nothing corresponding to re-entrant neuroanatomy. Indeed, if asked, what characteristic uniquely differentiates higher brains from all other known objects or systems, we would say "re-entrant organisation".
Lastly, while these first three conditions exist to a greater or lesser extent in all animals with brains, the human brain, with the biggest size, most complex morphology, and a relatively plastic neo-cortex, has evolved these relationships to such a degree of dynamic functionality that we not only possess 'a remembered present', the comprehension of an immediate scene (recall but not memory) like most animals – dogs for instance – but, further, we possess as a species the ability to recall or, more correctly, reconstruct memories, to imagine and plan, to consider the future, to reflect upon the past, to be aware that we are aware. At this level we have become not just a social animal, but a conscious social animal.
Whether we are aware of it or not, in this arena adaptive selection has found its highest expression - our social being. We interact as social beings in society and we can reach the most sophisticated form of selection – conscious selection of ideas, aesthetics, moral choices, philosophies and competing arguments. These conscious choices, however, do not necessarily do away with our rawer appetites, and at times can be in direct competition with them. Nor can they normally be made purely in the abstract, seperate from the social, cultural and economic superstructure in which we are embedded. I will deal further with the remembered present and how in higher brains this develops into full consciousness in part two
I know I have probably thrown just thrown a number of terms at you that you not have heard before. I counsel patience. We will consider the neuro-anatomical 'mechanics' in a little more biological and explanatory detail in a moment. Although it is impossible to adequately convey or deal with the richness of a theory originally expounded in hundreds of thousands of words in a few thousand I hope the reader will stick with me through some of the more complex biology (and occasionally philosophy of mind) and be rewarded by an understanding at a lay level that is at least sufficient to see where this is leading in terms of the overall thesis I am outlining. Firstly, however, it will be necessary to briefly touch on some of the misunderstandings some of Edelman's formulations and writing have given rise to.
Everything in the Garden...
The philosopher Daniel Dennett in his often excellent and seminal work Darwin's Dangerous Idea affords Edelman only two dismissive mentions in footnotes. Although slightly less churlish in his own book on the subject at hand, Consciousness Explained, (it isn't) he sums up Edelman and TNGS thus:
"Edelman is one theorist who has tried to pull it all together, from the details of neuro-anatomy to cognitive psychology to computational models to the most abstruse of philosophical controversies. The result is an instructive failure. It shows in great detail just how many different sorts of question must be answered before we can claim to have secured a complete theory of consciousness, but it also shows that no one theorist can appreciate all the subtleties...Edelman has misconstrued, and then abruptly dismissed, the work of many of his potential allies, so he has isolated his theory from the sort of sympathetic and informed attention it needs to be saved from its errors and shortcomings."
- my emphasis
Dennett writes from a functionalist/computationalist perspective so it's perhaps understandable that Edelman – always a handy one with the polemical phrase for television or the media – has ruffled feathers with what often appears to be a peremptory dismissal of that entire field. Edelman sometimes does tilt at windmills out side of his own field of neuroscience and sometimes he gets it wrong. For instance, in a postscript to Bright Air, Brilliant Fire, he challenges Noam Chomsky's view on linguistics, particularly the view, based on the universality of rules of syntax across the human species, that all human beings must possess a what Chomsky has called a language acquisition device.
Chomsky, of course, isn't suggesting that there is anything inside our heads apart from the matter of our brains, and I would argue that the view of human consciousness inherent in TNGS as requiring both innate, evolutionarily determined, species specific features and a dynamic capability to respond to environmental novelty is not necessarily dichotomous with Chomsky's work.
Similiarly, Dennett and others are concerned that Edelman makes a category error in dismissing computationalism. They see Edelman's war cry for an understanding of the biology of the brain as a basis for approaching the complex processes of consciousness as a rejection of the idea of 'substrate neutrality' – that consciousness is a material process that, in theory, should not be dependent on any particular substrate i.e. the carbon and water based brain, but should in theory be possible in other suitable media. They worry perhaps that Edelman's critique of functionalism and computationalism as a method of understanding consciousness implies a rejection, for instance, of Alan Turing's fundamental mathematical insight that all physical and mathematical processes can, in theory, be represented and computationalised by a universal machine consisting of a (potentially infinite) series of ones and zeroes. This is the insight on which all modern computing is fundamentally based.
Although there are times when I wish Edelman was a little more careful and a little less provocative in his language, I don't believe he thinks anything other than that consciousness may well be, and probably is, substrate neutral. He specifically talks about the development of artificial consciousness in the future, uses computational modelling in his own experiments and very much sees consciousness as a process rather than a substance or a thing. He speaks of Turing's 'powerful' mathematical tool and I don't believe he rejects the principle of universal computation at all.
Finally, Edelman suffers from his own success; not only in dissolving the falseness of the dichotomies within the nature/nurture debate; between reductionism and complexity or emergence, and between innateness (what is given by nature to human consciousness) and what is brought to our conscious selves through interaction with the global environment; but in showing the interdependence and dialectical relationship of these things through the penetrating lens of Darwinist thinking.
Some on the reductionist/innateist side of the argument cannot forgive him for his attempt to describe this complex and emergent nature of consciousness, or his stress on the uniqueness of individual histories and the importance of environmental input in somatic time in the development of our abilities, sensibilities and sense of self. On the other side, would be 'holists' and 'nurturists' view him with suspicion because his theory also implies acceptance of human nature, a substantial degree of innateness, and an adaptive explanation for the commonalities we experience and feel as humankind, wherever we hail from and whatever our culture.
I can only appeal to those who have rejected or passed over Edelman for these reasons to revisit him and think again. We should not throw out a substantial baby because of some muddied bathwater.
I will not argue in this narrative that Edelman is absolutely right about everything or that TNGS is complete in all respects and cannot be improved upon, only that it is, so far, as backed by massive evidence, the best theory we have available; that it is a materialist theory, a theory of emergent phenomena, a theory of mind as process not substance, and a theory that, to use Marx's terms, encapsulates and places in their proper relationships both our species being and our social being. Edelman and his co-workers have been refining and developing the theory for over two decades. As Edelman and Tononi themselves say in Consciousness: How Matter becomes Imagination
"Our claim is that we may capture the material bases of mind even to the extent of having a satisfactory understanding of the origins of exalted things, such as the mental. To do so, we may have to invent further ways of looking at brains and their activities. We may even have to synthesize artifacts resembling brains connected to bodily functions in order to fully understand those processes. Although the day when we shall be able to create such conscious artifacts is far off, we may have to make them – that is, use synthetic means – before we deeply understand the processes of thought itself. However far off the date of their construction, such artifacts shall be made. After all, it has been done at least once by evolution. The history of science, particularly of biological science, has shown repeatedly that apparently mysterious or impassable barriers to our understanding were based on false views or technical limitations. The material bases of mind are no exception."
So how does my brain work then?
The structure of the brain is incredibly complex and incredibly important. Some have criticised the ideas of Edelman as over emphasising the plasticity of the brain and, in particular, the cerebral cortex. But it is unarguable that this plasticity has been shown; from cases where certain patients have suffered brain damage and other areas of the brain adapt to that function, or from experiments where electrical stimulation of parts of the cortex have produced reports of highly individuated sensations from experimental volunteers – such as 'that makes a Metallica song go through my head' or 'that makes me think of my mom baking apple pie'.
But just as children require reasonable and consistent boundaries in order to develop, the brain requires structure in order to facilitate adaptive plasticity. It also requires a massive number of possible neuronal groups and mappings from which to select in response to environmental or social stimuli, and to novelty in the world. In selectional system high redundancy allows significant adaptive differentiation.
"The adult human brain weighs about three pounds and contains about 100 billion nerve cells, or neurons. The most recently evolved outer corrugated mantle of the human brain, the cerebral cortex, contains about 30 billion neurons and 1 million billion connections, or synapses. If we counted one synapse per second we would not finish counting for 32 million years. If we consider the number of possible neural circuits (in the brain as a whole), we would be dealing with hyper-astronomical numbers: 10 followed by at least a million zeroes. (There are 10 followed by 79 zeroes, give or take a few, of particles in the known universe)."
- Edelman, Tononi, Consciousness
Bearing this in mind, TNGS identifies three main topological arrangements of fundamental neuro-anatomy in the brain:
1. The thalamo-cortical system
The thalamus is reciprocally connected by re-entrant maps to the cerebral cortex. Different cerebral cortical areas and their associated thalamic nuclei are highly specialised and are associated with specific types of environmental stimuli; visual, acoustic, tactile etc
2. The cerebellum, hippocampus, basal ganglia and cortex
This is a system of parallel and unidirectional extended nuclei linking the cortex to the cerebellum, hippocampus and the basal ganglia.
The cerebellum is concerned with the co-ordination and synchrony of motion and also appears to have substantial involvement in certain aspects of thought and language.
The basal ganglia, whose nuclei project to the thalamus and back to the cortex and is known to be involved in the planning and execution of complex motor and cognitive acts. Significantly, this system is dysfunctional in Parkinson's and Huntingdon's diseases.
The hippocampus sends multiple projections to and from multiple cortical areas. Current neuroscience theorises that this system probably subserves many functions but it certainly plays a major role in consolidating short term memory into long term memory in the cerebral cortex.
3. The value system
A diffuse fan of extended nuclei which projects to huge portions of the brain and possibly all of it. The origins of this fan is found in a relatively small number of neurons in the brain stem and hypothalamus, two parts of the brain which evolved very early, and which consist of
- The noradregenic locus coeruleus
- The serotegenic raphe nucleas
- The dopaminergic nuclei
- The cholinergic nuclei
- The histaminergic nuclei
As the names of these nuclei suggest they are responsible for the chemical stimulation of neuronal groups in positive reinforcement of adaptive responses for the organism to the environment. You will probably recognise and be familiar with some of the chemical compounds underlying these systems and which may or may not be associated in your mind with brain activity and the drugs and chemicals which are known to alter it – adrenalin, dopamine, serotonin etc. This system affects not only neural activity but neural plasticity. It yields selection. That is to say, an adaptive change to synaptic response strength.
How this complex tri-partite structure is capable of constructing a coherent scene, a 'remembered present' in terms of our conscious experience, and how, in higher brains that is built upon to further levels of coherence – a remembered past, and imagined future, reason, rationalisation, tastes and aesthetics, desire and longing and regret – will be developed further in further issues of The Point.
For now it is enough to note that this theory renders any notion that it is only, or 'mainly', nature or nurture, evolution or environment, that plays the true critical role in the development of our mind as laughable as the idea that earthquakes can be predicted by chicken's entrails. And, that in outline at least, we have a neuro-scientific theory of mind that has no need of any ghosts in the machine.
Our beautiful brains have been built by natural selection over evolutionary timescales as a response to innumerable environments.
They have built a structure capable, when fully functioning, of allowing adaptive value led selection in body time of neuronal groups and sufficient neural plasticity to allow response to novelty in given environments.
In so doing, from matter, nature has given rise adaptively to a process, an emergent phenomena, the thing we call consciousness, which is dependent on and derives from the organisation of the matter, but is more than simply the matter itself because it requires an interpenetrating and interlocking factor; the external world.
In turn, this has created a relatively new thing on this Earth – a group called homo sapiens that has both species being and social being. We may want to refer to such creatures as Persons and a global theory of their species being and social being as a Theory of Persons. (There may be others who fit this view of 'person' - apes, dolphins, whales, elephants, artificial and alien intelligences and so on - but I'll deal with that further down the line).
A brain without the environment it has been evolutionarily built to interpret, respond to, and survive in, remains a squidgy mass and nothing more. Consciousness would not develop. An environment without a brain structured adaptively to respond to it, and any novelty it might throw up, is like the proverbial tree that falls in the forest. It may still exist but it will never be the subject of conscious thought.
In terms of what it means to be human, to be a person, it is no longer a question of nature or nurture, but nature via nurture, and nurture via nature, to use Matt Ridley's celebrated phrase.
Blank slate-ism, its corollary, fundamentalist social constructivism; and its opposite, biological determinism, are, all three, dead as the dodo.
Steve Arnott, March 201 4
Bright Air, Brilliant Fire – Gerald Edelman, Penguin Books
Consciousness: How matter becomes imagination – Gerald Edelman & Giulio Tononi, Penguin Books
Consciousness Explained – Daniel Dennett, Penguin Books
Darwin's Dangerous Idea - Daniel Dennett, Penguin Books
Nature via Nurture – Matt Ridley, Harper Perennial