Читать книгу Why Us?: How Science Rediscovered the Mystery of Ourselves - James Fanu Le - Страница 12

‘Homo sapiens is not simply an improved version of his ancestors, but a new concept, qualitatively distinct from them … A totally unprecedented entity has appeared on the earth. All the major intellectual attributes of modern man are tied up in some way with language.’

Ian Tattersall, Curator, American Museum of Natural History

The most striking feature of the arrival of modern man is its suddenness and completeness, epitomised most obviously by the beauty and originality of those artefacts he left behind: the ‘pride of lions’ portrayed in perspective on the walls of the Chauvet cave; the beads and jewellery for self-adornment in this and the ‘next’ world; drums fashioned from mammoths’ bones to celebrate, with singing and dancing, the wonders of the natural world; oil lamps, harpoons, spear-throwers. All the features in short – artistic, technical, economic and religious – that can be found in contemporary society.

The precipitating factor in that cultural explosion must, by common consent, be tied up in some way with language. The Cromagnons had a ‘passion for art’, so an obvious starting point in searching for the qualitative difference that language might make, and which would distinguish them from their antecedents, is to ask what a painting or a sculpture of, say, a bison, is. It clearly is not a bison, nor the reflection of a bison, nor the imaginative figment of a bison – as in a dream. It is not a sculpture of a specific object, but rather a generalised image of a class of objects: it stands for, is symbolic of, bison in general. It is the idea of a bison. This ability of Cromagnon man to conceptualise things and feelings as ideas, and to express those ideas as words, introduces an entirely new dimension into the universe.

First, language – and it is a most extraordinary thing – allows us to ‘think’, by assigning words to objects and ideas. Then it becomes possible to express a logical idea by applying grammatical rules to the arrangement of those words, and linking them together sequentially in a sentence. And more, the faculty of language allows us to take those thoughts ‘brought into existence’ by language and insert them with complete precision into the minds of others for them to share, or to disagree with. Language makes the world intelligible, by allowing man to transmit his thoughts and experiences in the form of accumulated knowledge from generation to generation – leading, perhaps inevitably, to the moment at the close of the twentieth century when he would ‘hold in his mind’s eye’ the history of the universe he inhabits. Language makes it possible to distinguish truth, the faithful reflection of reality, from falsehood, and this, as the philosopher Richard Swinburne points out, is the foundation of reason (obviously), but also of morality, for ‘it gives man the capacity to contrast the worth of one action to that of another, to choose what he believes worthwhile … and that gives us a conception of the goodness of things’. Thus humans, like all living things, are biological beings constrained by nature’s laws; nonetheless language liberates our mind from the confines of our material brain, allowing us to transcend time and space to explore the non-material world of thought, reason and emotion. So, ‘All the major intellectual attributes of modern man are tied up in some way with language,’ as Ian Tattersall argues. Where then did language come from?

The prevailing view, till recently, held that this remarkable faculty required no specific explanation, and could be readily accommodated within the standard evolutionary rubric of the transformation of the simple to the complex. Language is explained (or ‘explained away’) as an evolved form of communication, no different in principle from the grunts or calls of other species. ‘I cannot doubt,’ observed Darwin in The Descent of Man, ‘that language owes its origin to the imitation and modification of various natural sounds, the voice of other animals and man’s own instinctive cries…’ So too contemporary evolutionary texts portray human language as an improved method of communication over that of our primate cousins, while emphasising the similarities in the larynx and vocal cords (which, however, are not so similar as they appear) as evidence for language’s evolutionary origin. ‘Language evolved to enable humans to exchange information,’ observes Robin Dunbar of the University of Liverpool.

In the 1950s the famous linguist Noam Chomsky challenged this interpretation of language as a more sophisticated form of primate communication by drawing attention to the significance of the remarkable alacrity with which children learn to speak. Language flows so readily, a ‘babbling’ stream of feelings, thoughts and opinions filling every nook and cranny of our lives, it is easy to assume it must be simple, simple enough for children to ‘pick up’ as readily as they pick up measles. Prior to Chomsky, the standard view held that children learned to speak in the same way as blotting paper absorbs ink, by soaking up the words they heard and then reiterating them. Chomsky argued this could not be so, pointing out the skill with which very young children learn to speak lies far beyond the intellectual competency of their years, for while they must struggle to grasp the elementary principles of mathematics, they acquire language with astonishing ease. An infant starting from a situation not dissimilar to that of an adult in a room of foreigners all jabbering away incomprehensibly, nonetheless:

‘Within a short span of time and with almost no direct instruction will have dissected the language into its minimal separable units of sound and meaning,’ writes linguist Breyne Moskowitz. ‘He will have discovered the rules of recombining sounds into words and recombining the words into meaningful sentences. Ten linguists working full-time for a decade analysing the structure of the English language could not programme a computer with a five-year-old’s ability for language.’

The aptitude of the young mind in mastering the staggering complexity of language presupposed, Chomsky argued, that humans must possess some form of highly specific ‘Language Acquisition Device’ hardwired into their brains that somehow ‘knows’ the meaning of words and the grammatical forms necessary to make sense of them. How, otherwise, can an infant know when its mother says, ‘Look at the cat!’ that she is referring to the furry four-legged creature, and not to its whiskers, or the milk it is drinking. Further, the ‘device’ must not just know what is being referred to, but the grammatical rules that permit the same ‘idea’ expressed in different ways to have the same meaning (‘John saw Mary’ conveys the same message as ‘Mary was seen by John’), but excluding meaningless variations. Further again, it transpires that children learn language in the same way, whether brought up in New Jersey or New Guinea, and acquire the same grammatical rules of ‘present’, ‘past’ and ‘future’ in the same sequence. This implies that the ‘device’ in turn must be sensitive to a Universal Grammar, common to all languages, which can pick up on the subtlest distinction of meaning.

Now, our primate cousins do not possess this ‘device’, which is why, clever as they are, they remain (in the words of the veteran chimpanzee-watcher Jane Goodall) ‘trapped within themselves’. By contrast, every human society, no matter how ‘primitive’, has a language capable of ‘expressing abstract concepts and complex trains of reasoning’. The million Stone Age inhabitants of the highlands of New Guinea, ‘discovered’ in 1930 after being cut off from the rest of the world for several thousands of years, spoke between them eight hundred different languages, each with its complex rules of syntax and grammar.

How then did the faculty of language come to colonise the human brain? ‘There must have been a series of steps leading from no language at all to language as we now find it,’ writes the linguist Steven Pinker, ‘each step small enough to have been produced by random mutation [of genes] and with each intermediate grammar being useful to its possessor.’ It is, of course, possible to imagine how language might have evolved in this way from a simpler form of communication or ‘protolanguage’, starting perhaps with gestures, moving on to simple words or phrases with a single meaning, with the rules for linking words into sentences coming later. Pinker’s intended parallel between the means by which our species acquired language and the infant’s rapid progress from burbling through words to sentences might seem plausible, in the way of all evolutionary explanations, and would indeed be reasonable if language simply ‘facilitated the exchange of information’. But, as Chomsky pointed out so persuasively, language is also an autonomous, independent set of rules and meanings that impose order, make sense of the world ‘out there’. Rules and meanings cannot evolve from the simple to the complex, they just ‘are’. The structure of sentences is either meaningful or meaningless. The naming of an object is either ‘right’ or ‘wrong’. An elephant is an elephant, and not an anteater. Hence Chomsky insisted, against Pinker, that those seeking a scientific explanation for language could, if they so wished, describe it as having evolved ‘so long as they realise that there is no substance for this assertion, that it amounts to nothing more than a belief.’ This, of course, is no trivial controversy, for language is so intimately caught up in every aspect of ‘being human’ that to concede that it falls outside the conventional rubric of evolutionary explanation would be to concede that so does man.

The dispute over the evolutionary (or otherwise) origin of language remained irresoluble till the late 1980s, when the first PET scans revealed how the simplest of linguistic tasks involves vast tracts of the brain in a way that defies any simple scientific explanation. Here every mode of language, thinking about words, reading and speaking them, is represented in different parts. The prosaic task of associating the word ‘chair’ with ‘sit’ generates a blizzard of electrical activity across the whole surface of the brain. Further, those scanning investigations revealed how, in the twinkling of a second that it takes to speak or hear a word, the brain fragments it into its constituent parts through four distinct modules concerned with spelling, sound (phonology), meaning (semantics) and articulation. These ‘modules’ are in turn then further subdivided ad (virtually) infinitum. The perception of sound, for example discriminating between the consonants ‘P’ and ‘B’, is represented in twenty-two sites scattered throughout the brain. There is something absolutely awe-inspiring in supposing we understand a word like ‘elephant’ only after it has been parsed in this way. And then, to compound it all, the brain must simultaneously while ‘parsing’ elephant also comprehend its meaning in its entirety, for the constituent symbols can really only be understood within the context of the whole word.

It is one thing to try to work out how the brain processes a single word (and that is baffling enough), quite another to extrapolate from such findings to try to imagine the same processes as they apply to a sentence, with its structure of ‘subject-verb-object’ and numerous subsidiary clauses. Move into the real world, with its ceaseless conversation, and the problem becomes insuperable. What sort of brain processes, one might ask, must be involved when a group of football fans convening in the pub before a match discuss their team’s prospects for the coming season – drawing on a vast storehouse of knowledge and judgement of the form of previous seasons, the strengths and weaknesses of their players, and assessments of the performance of their rivals. How do they pluck from the storehouse of their memories the right words, or conjure from the rules of syntax and grammar the correct sequence with which emphatically to argue their opinion? How does the electrical firing of the neurons in their brains represent words and capture the nuance of their meanings?

And so? ‘Language flows so readily, that it is easy to assume it must be simple.’ But language only appears simple because it has to be so. There would, after all, be little point in humans acquiring this novel and powerful mode of inserting their thoughts directly into the minds of others if it took many years to get the hang of, and was difficult to use. But that apparent simplicity is, as already noted, a mark of language’s profundity, concealing the inscrutable complexities of brain function that make it appear to be so.

The major legacy of linguistics and neuroscience in the past few decades has been to reveal the complexities concealed behind that apparent simplicity while drawing attention at the same time to how the faculty of language requires major changes in every aspect of the functioning of the brain: a massive increase in its memory capacity so as to be able to store that vocabulary of forty thousand words, together with the provision for their near-instant recall; a profound deepening of the mind’s emotional repertoire with its feelings of sympathy and affection; the powers of reason; the moral distinction between right and wrong; and the imaginative intelligence with which poets and writers express themselves in unique ways.

The opportunity to reflect further on such matters will come later, but for the moment we must briefly return to contrast the conventional evolutionary portrayal of the origins of that ‘totally unprecedented entity’ Cromagnon man with how, in the light of the above, they now appear to be. To be sure, that steadily expanding brain over the preceding several million years, with its much enhanced neuronal firepower predisposed to those higher intellectual attributes, particularly language, and thus that cultural explosion of technical innovations and artistic expression. But that much-expanded brain by itself does not explain the phenomenon of language, nor why the evidence for its undoubted ‘benefit’ of being able to think, act and make sense of the world should have emerged so late and so suddenly. Why did the brain continue to expand in size for those millions of years when the ‘pay-off’ was so slight, and the attendant hazards of obstructed labour and dependent offspring so large? And this conundrum becomes yet more puzzling now we know that language is not just some bolt-on addition to the primate brain, but occupies large areas of it, and required the massive extension of those other attributes of mind, such as memory and intelligence, on which it depends.

Here neither of the two proposed evolutionary scenarios – that language evolved ‘early’ or ‘late’ – is convincing. The proponents of the ‘early’ scenario infer (quite rightly) that it must have taken millions of years for so complex a system to have evolved – all the way back to Turkana Boy’s people, Homo erectus, and beyond. Why then, one might ask, did he exhibit so little evidence of the ‘culture’ that language makes possible? The ‘late’ theorists claim language to be unique to Homo sapiens, the spark that lit the cultural explosion that separates him from his nearest relatives – but that would presuppose that it evolved over the mere 100,000 years since his emergence from Africa. This dispute cannot be resolved, but it serves the useful purpose of drawing attention to our profound ignorance: we no longer have the vaguest inkling of what caused the ‘switch to be thrown’ to inaugurate that first and most astonishing of all civilisations. Thirty-five thousand years on, we humans can draw on a vast treasure house of the cumulative knowledge and technology of the many civilisations that have had their moment in the sun, the Egyptians, Greeks, Romans, Arabs and so on. The genius of the Cromagnons, with their passion for art and wittily decorated spear-throwers, is that they had to work it all out for themselves.

This then is the riddle of the Ascent of Man: how and why twenty or more distinct species of hominid should, over a period of several million years, have undergone that wholescale anatomical transformation required for standing upright, and then followed it up with acquiring that prodigiously sized brain whose potential to comprehend the workings of the universe appears so disproportionate to the needs of the life of a hunter gatherer. It seems obvious that man’s sophistication and intelligence would have conferred some biological advantage, but all living things – birds, bats, dolphins and so on – have their own highly specialised sort of intelligence, different from our own, but which nonetheless maximises their chances of survival. The question, rather, as the biologist Robert Wesson puts it, is why the human brain should come with those striking mental powers, such as the capacity to compose symphonies or to solve abstruse mathematical theorems, that ‘are not of the kind likely to be rewarded by numbers of descendants’.

The further subsidiary and related riddle is why, for the best part of 150 years, the scientific orthodoxy has prevailed that we know the answer, at least in principle, to that riddle of the Ascent, when, as the palaeontologist Ian Tattersall acknowledges, ‘we have only the dimmest perception of how that dramatic history unfolded’. It has taken just a few pages to draw out the contradictions, at every turn, in the prevailing scientific certainty of ‘natural selection’ as the driving force of the Ascent of Man. There is, of course, no more self-evident truism than that nature ‘selects’ the strong and the fit at the expense of the weak and less than perfect. But that mechanism, by the same logic, can scarcely be invoked to account for standing upright and that massively enlarged brain which, by rights, should have so gravely compromised the survival prospects of those distant ancestors. There is nothing obscure in the observations outlined above: the anatomical implications of the upright stance and the obstetric hazards of that enlarging brain are well documented. Yet there is not the slightest hint in standard evolutionary texts or in the graphic museum displays of the Ascent that they might be problematic – while those who might think so are derisively dismissed, as we have seen, as ‘stupid, ignorant or insane’.

Most people get by well enough without the slightest inclination to speculate about their origins – and if they do, there is much consolation in that reassuring image first captured by Thomas Huxley of our onward and upward ascent. Still, it is surprising how that history of our origins becomes instantly so much more fascinating and intriguing the moment one reflects, for example, on the marvels of the composite integrity of the human skeleton, or the hidden complexities of grammar that can nonetheless be grasped by a two-year-old child. This discrepancy between the beguiling simplicities of the evolutionary theory and the profundity of the biological phenomena it seeks to explain is very striking. Its claims can never be ‘put to the test’ of experimental verification, as there is no way of telling one way or the other whether the process of natural selection really does account for those extraordinary biological events millions of years ago. The standard evolutionary explanation is, in short, irrefutable – or was irrefutable, until the uncompromising verdict of the genome projects, where the random genetic mutations that might set us apart from our primate cousins, mice, flies or worms are nowhere to be found.

It can, admittedly, be very difficult to see what all this might add up to, but clearly the ramifications of those seemingly ‘disappointing’ outcomes of the New Genetics and the Decade of the Brain run very deep indeed. We need to know why we have been seduced into supposing that science knows so much more than is clearly the case – and that means exploring further that seemingly unbridgeable gap between those two ‘Orders of Reality’ to seek out the forces that might conjure the beauty and complexity of the natural world from the monotony of those chemical genes, and the richness of human thought and imagination from the electrical activity of the brain.

But for that we need a yet broader, more Olympian perspective still, to take the full measure of the scope (and limits) of scientific knowledge as so recently revealed, and of how, paradoxically, those ‘disappointing’ outcomes turn out to reveal profound truths about the nature of genetic inheritance and the human mind, so long concealed from view.

There is no better way to start than through that most fruitful insight into the nature of things that comes with the experience of ‘wonder’, whose dual meaning those Cromagnons would instinctively have appreciated. They would have ‘wondered at’ the pervasive beauty and integrity of the natural world, inferring there was a greater significance to their existence than they could know. They would have responded, too, to the human imperative to ‘wonder why’, seeking out in the regularity of the movement of the stars and the diversity of form of living things those causes, patterns and explanations of the natural world that are ‘the beginning of all knowledge’.