The Great Divide

cold, tundra-like forests, or extensive grasslands. Some move between different landscapes. They are surrounded by animals – by birds or fish, by predators perhaps. They share their landscape with plants – grasses, shrubs, trees and flowers, some more nutritious, more medically useful and more psychoactive than others. And people live among weather: they live surrounded by different and systematic admixtures of sunshine, rain, wind, hail, lightning, they suffer natural catastrophes such as earthquakes, volcanoes, hurricanes and tsunamis. They live under the heavens – the sun, the moon, and the stars including the Milky Way. And finally they live on land, on continents, that are scattered randomly across the spherical globe and are in different relationships with the great oceans. That land is primarily north-south in orientation, or east-west, configurations that are basic to weather and climate and to the history of weather and climate. All of these factors, we can now see, come together to create, broadly speaking, two great entities across the world, two configurations whose similarities and differences help explain the separate development of mankind on the two great hemispheres.
    What is also clear from the story this book has told is that these combined factors – let’s call them environmental factors – operate on human beings to produce in them, and this is the second stage of the three-stage process, an ideology , a way of looking at the world, a way of understanding and interpreting that world, a way of making sense of the Earthly phenomena that manifest themselves and surround human beings everywhere. It is straight away evident from this book that ideologies vary much more in the Old World than they do in the New, in ways that are discussed later.
    In the third stage of the process, the ideologies that people adopt as a result of their surrounding environment, and the technologies they develop, continue to interact with that environment, which of course itself continues to change, partly as a result of the evolution of the Earth, of cosmological, astronomical and geological events, and partly as a result of the changes that overtake humankind itself as a result of the first two stages. 4
    And this perhaps is the second most interesting generalisation to emerge from our story, after the initial formulation of ideology based on the environment/climate/human conjunction: this is the determinant of what Fernand Braudel and the French historians would call la longue durée . History is in effect the narrative of humankind’s changing ideology and its continuing interaction with the environment – economic, ecological, technological. 5
    If this analysis is correct, then it helps us understand the very different trajectories followed in the two hemispheres. As was outlined in chapter five, the Americas are a much smaller landmass than Eurasia, even without Africa added on. Moreover the New World is, as Hegel, Jared Diamond and others have pointed out, oriented in a north-south direction rather than east-west, as Eurasia is. This orientation in itself impeded development, relatively speaking, by slowing down the rate at which plants – and therefore animals and civilisation – can spread. This was not wholly bad, of course. It meant that in particular localities many species evolved. (The tropical rainforest, for example, occupies 7 per cent of the land surface of Earth but nurtures well over 50 per cent of the animal and plant species. Because there are so many insects and small mammals in the rainforest, energy is lost along the food chain, with the result that large mammals are relatively rare – and large mammals have played a vital role in our story.) 6 But the north-south orientation of the New World, in conjunction with other factors to be considered shortly, did undoubtedly slow down the development of humanity in the Americas. It was more a technical limit before anything else, but it had a knock-on effect too, as we shall see.
    Alongside the general geographical alignment of the continents went an associated climatic variation, of which the most important elements were the Monsoon, the El Niño Southern Oscillation (enso), and the violent activity caused by volcanoes, earthquakes, winds and storms. The importance of the monsoon lies in the fact that, for the last 8,000 years, since the time of the last great flood, outlined in chapter two, the monsoon has been decreasing in strength. The