Peter Watson: The Great Divide: History and Human Nature in the Old World and the New

more often and more radically than did the ideologies of the Americas. And that while this was due to some extent to differences in climate and geography – the weakening monsoon in the Old World and the increasing frequency of El Nin˜o in the New World – it also had a great deal to do with the role of the domesticated mammals and in the New World of hallucinogenic plants. We may therefore say – exaggerating only slightly – that the core of Old World history was deﬁned largely by the role of the shepherd, whereas in the New World an equivalent role was fulﬁlled by the shaman (p. 519).


Introduction
Peter Watson is an intellectual historian, who writes big, ambitious books. His previous work, The German Genius (2010) did an admirable job surveying the extraordinary florescence of German intellectual thought from the seventeenth to the twentieth centuries. It was an accessible, although lengthy, guide to not only the great names-Goethe, Gauss, Kant, Einstein-but also managed to include a host of relatively minor figures, while making sense of the whole.
In The Great Divide, Watson sets himself an even more daunting task: he tries, by tracing human history from origins to the early modern period, to account for why the New World (North, Central and South America) has diverged from the Old. This divergence, in terms of civilisation and power, is what forms the 'great divide'. Like the German Genius, then, The Great Divide is necessarily a work of synthesis, pulling together scholarship from a host of disciplines: anthropology, comparative theology, archaeology, climatology, biology, geology and history. The diversity of this list is a clue to the sources of Watson's overall argument. The causes of the Great Divide are as much natural as social. To this extent the book is an argument about global environmental history as it relates to grand, large-scale trends in human history.

Comparing the Old and New Worlds
Of course there are many surface similarities between the Old and New worlds, both in terms of civilisations and the environments they formed and grew in. A superficial civilizational similarity, for example, is the appearance of monumental pyramid-type structures. More significantly, humans have always been faced with the needs for food and shelter, have been able to move across some landscapes more easily than others, and have watched a shared sky of sun, moon, stars and planets. Everywhere there has been adaptation, cultural and physical, whether home was a jungle, coastal bay or tundra.
But then there are differences. Like Jared Diamond, in Guns, Germs and Steel, Watson notes the significance of two natural contingencies: the north-south orientation of the New World, which contrasts with the east-west sprawl of the Old World, and the accidents of location of animals and plants affording domestication. In addition, Watson highlights two further enormously significant geoclimatical phenomena: the monsoon, which brought rain to Asia (and elsewhere) but has weakened over the millennia, and El Niño, which, in the years of operation, dramatically shifts weather patterns, not least over South America. El Niño has strengthened over time. Finally, to this list of significant environmental factors, Watson picks out two further ones, which, I think it is fair to say, he gives more prominence to compared to other commentators. The first is events of spectacular geological violence, especially great volcano eruptions. The second is the geo-location of strong hallucinogenic plants-there are simply more in the Americas than in Eurasia, 80-100 compared to 8-10, and they are probably stronger.
To summarise Watson's argument in a nutshell: humans in the New World were faced with a natural environment that was qualitatively more hostile than in the Old World. This fostered an ideology, religiously expressed, of angry gods that had to be appeased. Inhabitants sacrificed so that gods would not do things. And this appeasement fundamentally did not work. This failure was a fundamental source of instability in New World civilisations. Endemic war (often for the seizure of captives destined for sacrifice) was a threat that, unlike natural catastrophes, could be manipulated by elites. In the Old World, where the problem was fertility rather than violent nature, of assuring the renewal of crops and animals, the ideology encouraged an appeal to fertility gods to let renewal happen. And it did seem to work (in the sense that, normally, new plants grew in spring, and domesticated animals reproduced). Watson writes: Fertility was an issue in the New World but, in the tropical rainforests, teeming with life and with plants growing in profusion all through the year (as manioc did, for example), and where the seasons varied, it was never the overwhelming issue it was in the temperate Old World. Much more important in the New World mindset were the feared and admired jaguar, and the weather gods -gods of lightning, rain and hail or violent winds, of thunderstorms, erupting volcanoes, earthquakes and tsunamis… (p. 512) Of course the Old World had its endemic instabilities too. The most important of these was the expansion of nomadic tribes and their conflicts with sedentary peoples. But this instability had the effect of driving technological change. Furthermore there was just more space, moving east-west, for Old World history to play out these tensions.

How the Old and New World Diverged
That's the static picture of Watson's overall argument. The outcome was a New World that would fold under Spanish conquest, aided of course by the unequal Columbian exchange of disease-bearing organisms, and therefore a divided modern world. Most of the book, however, is an engaging, and at times enjoyably speculative, dynamic, chronological tracing of human history.
Modern humans evolved around 150,000 years ago, and perhaps as early as 25,000 years later had left Africa, probably across the southern end of the Red Sea, which, because of the recent Ice Age, was 230 feet lower than present. Moving around the extended coast (much of it now almost, but perhaps not irretrievably, lost to archaeology) 2154 humans reached Australia, Europe, and throughout Asia. By 25,000-20,000 years ago humans found Beringia, the land bridge straddling Old and New worlds which formed a bottleneck in expansion. Watson uses both archaeological and genetic science secondary sources to tell his story, treating the latter with sensible care and balance. It is interesting the extent that these two specialties, one old, one new, have displaced comparative linguistics, the evidence from which Watson also addresses, as guides to ancient pasts.
Watson also draws upon myth structures, such those of the watery creation of the world, the separation of earth from sky, and floods. He agrees that myths encode memories of 'distant occurrences that were so catastrophic, traumatic and bewildering to ancient peoples' (p. 23). The most important area for new myths, he argues, was south-east Asia, which would have formed a more extensive landmass before the waters rose. Creation, as in 'let there be light', for example, might refer to the skies gradually clearing of black dust after the Toba eruption of 74-71,000 years ago. Toba was the 'biggest eruption on earth during the last two million years, a massive conflagration that would have released a vast plume of ash thirty kilometres high … spreading north and west' (p. 24). A site in central India, for example, has an ash layer 20 feet thick. The spread of peoples, fleeing environmental disasters such as catastrophic volcanoes and rising sea levels, took these myths, and possibly 'the early skills of civilisation, such as agriculture' (p. 27), with them out of south-east Asia. For good measure, Watson throws in a perfect storm of interlocking astronomical cycles, provoking 'very dramatic and very sudden climate change' (p. 30), including floods, around 22-23,000 years ago. It's fun, but speculative, a kind of Velikovsky rewritten for today's era of Global Warming.
Watson is on surer ground when discussing ideological inheritance and natural history. The shamanism of Asia was carried through Beringia into the New World. Shamanism is marked by the presence of special individuals who, often assisted by various means of mind-changing practices, can travel between this world and the other worlds, of gods and spirits, to intercede on behalf of their human clients. Hallucinogens, which as we have seen were stronger in the New World, assisted the shaman's flight. In North America, the humans, as they travelled rapidly east and south, met creatures that never been hunted. These chapters provide a good summary of ancient American history.
Watson alternates between New and Old World developments, always combining environmental, social and intellectual history. The contrast between patterns of domestication is perhaps the most important factor in the great divide. There is an interesting argument that relates the loss of innocence to the domestication of dogs: ancient humans may not have realised the link between sex and birth until relatively late. There must have been a time when our animal ancestors were not conscious of this link, and there's certainly a time later when we are, so when was the knowledge gained? Watson suggests it became obvious with the domestication of dogs. The consequences were social (ancestors are personal in a new way) and cultural (myths of the fall).
Domestication of animals and cereal plants, the Neolithic revolution, may have been precipitated by climate change (drying land producing more non-wooded land amenable to work before metal tools), population crisis (combined with over-hunting), or perhaps increased disease (as warming combined with the disappearance of megafauna hosts meant that humans suffered more infections) which forced the hunter-gatherers to adopt sedentary life if they were to reproduce in sufficient numbers to survive. Furthermore, in Ed Sherratt's very useful term, there was a 'secondary products revolution' (p. 139). Domestication did not just mean a new, and perhaps a larger and more reliable food supply, but also a sparked a chain reaction of technological developments of a secondary character, from pottery, ploughing, chariots, milking and riding-the last being, in Watson's words 'four things that never happened in the New World' (p. 139). And with sedentary domestication came the fertility gods.
In the New World, however, patterns of life based on hunting were either sustainable (as was the case with the plains Indians and the bison), or were replaced with sedentary civilisations that had to draw upon a much smaller repertoire of domesticated organisms. Furthermore, the environment was more hostile and the drugs stronger. Watson provides a clear overview of some of the new, and very exciting, archaeological discoveries that have added the Aspero/Caral Norte Chico and Chavín de Huántar cultures to the more wellknown Olmec, Aztec and Inca stories. Ritualised, extreme violence emerges as a common theme.
Watson's next major phase in human history is substantially indebted to Karl Jaspers' 1949 notion of the 'axial age', the broadly contemporary emergence of systems of thought in the Old World that encouraged restraint, including Confucianism, Daoism, Buddhism, Jainism, Upanishadic Hinduism, prophetic Judaism and Greek philosophical rationalism. Watson, an intellectual historian, considers these intellectual developments to be more significant than technological ones: Many innovations -innovations in ideas and knowledge rather than technology -occurred during these years and, for the thesis of this book, this is when a big gap opened up between the two hemispheres. A series of interlinked changes … transformed humankind's understanding of itself in the Old World in a way that had no parallel in the Americas (p. 324).
In fact, Watson contradicts himself here, albeit slightly. He offers the figure of Ce Acatl Topiltzin Quetzalcoatl, who proposed substituting human sacrifice with animal sacrifice, as a 'parallel of sorts' (p. 472) with the Old World axial age prophets. However, as Watson notes, 'in Mesoamerica Topiltzin failed: he lost the argument and he lost his position' (p. 473).
In summary, Watson concludes: We can now see that the main difference between the Old and the New World civilisations … is in their patterns of adaptation to different environmental circumstances, and that the Old World ideologies changed more often and more radically than did the ideologies of the Americas. And that while this was due to some extent to differences in climate and geography -the weakening monsoon in the Old World and the increasing frequency of El Niño in the New World -it also had a great deal to do with the role of the domesticated mammals and in the New World of hallucinogenic plants. We may therefore say -exaggerating only slightly -that the core of Old World history was defined largely by the role of the shepherd, whereas in the New World an equivalent role was fulfilled by the shaman (p. 519).

Conclusion
There are necessarily weaknesses in such a sweeping text. China, for example, while making a few, comparative appearances, is not placed in the centre of global history in a way that, arguably, it should be. In terms of originality and conciseness, the Watson's Great Divide is not as exciting a reading as Diamond's Guns, Germs and Steel. However, it is an engaging guide to a mass of recent scholarship across a range of disciplines. The length of The Great Divide means that it is unlikely to be used for teaching. Indeed the market for the book is more general than a narrowly educational one. It is a trade book not a text book. However, I think there will be classes where parts of the text may well be used with benefit. First, as a global history, Watson offers both a good and readable synthesis. Second, with the specific influence he attributes to environmental factors such as violent nature or the biogeography of hallucinogenic plants, The Great Divide offers a distinctive thesis that might be summarised and contrasted to others' work.
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