Comprehensive theories of history are rather out of fashion nowadays; the last professional historian to undertake such a task, the late Arnold Toynbee, seems to be little read today. This has not deterred Jared Diamond from attempting the same feat, even though, or conceivably because, he is not a professional historian. He is in fact something of a polymath: a professor of physiology at the University of California Medical School, he has also been an ecologist and zoologist and has studied the bird life of New Guinea; he is the author of The Rise and Fall of the Third Chimpanzee. With this broad background in the life sciences it is perhaps not entirely surprising that this book, though subtitled as a history, is perhaps better described as an extended meditation on a conundrum.
The conundrum in question is one that was posed to him in 1972 by Yali, a New Guinea man. Why is it that certain societies, notably the Europeans, have acquired so much technology and power while others, such as Yali's own people, remained in the Stone Age until the Europeans arrived?
At one time this discrepancy was ascribed, at least by the Europeans, to the innate superiority of the white race, and this idea is still prevalent today in many quarters. But Diamond has little difficulty in disposing of it; indeed, his impression is that "primitive" people like the New Guinea natives are, if anything, more intelligent on average than white people. So the answer to Yali's question is not self-evident. And the question can be generalized, to ask why it is that peoples of Eurasian origin, especially those still living in Europe and eastern Asia, as well as those transplanted to North America, dominate the world in wealth and power. To put it differently, what was it that determined the geographical distribution of wealth and power and caused it to be so uneven?
The answer to this question which emerges in the course of the book is woven from several strands. One is agriculture. The invention of farming was not the unmitigated blessing it is sometimes claimed to be but it had a huge impact on people's lives and was an essential precondition for the development of advanced technology. However, in terms of their suitability to sustain agriculture, some areas of the world were much better than others. Eurasia was particularly favoured in this regard, partly because it extended mainly in an east-west direction instead of north-south, like the Americas, and with relatively few major barriers to communications; this meant that crop plants adapted to a particular seasonal pattern could be cultivated over a wide area. Another important consideration was the availability of large mammals for domestication; most species, it turns out, are unsuitable in one way or another, but Eurasia, once again, proved to be specially fortunate in this respect too.
Another strand in the answer comes from disease—the germs of the title. The invention of agriculture permitted the growth of population in Eurasia, and the consequent crowding facilitated the evolution of microbes capable of causing disease. The Eurasian populations acquired resistance to these infections but the populations of America and other zones had no immunity, so they died in large numbers when they encountered the new germs.
A third strand is made up of inventiveness. Why are some societies technologically inventive while others remain static and unchanging for hundreds or even thousands of years? Diamond discusses this in relation to geography and also local needs, making the point that there is far more variability in this respect than is generally realized, even within a fairly localized region. Easy communication across large distances seems to have favoured the spread of inventions in Eurasia.
Yet another strand is the political question. In common with a number of other thinkers, Diamond sees the transition from a hunter–gatherer society to an agricultural one as favouring the growth of centralized states, in which those people at the centre acquire more prestige and power than others. The result is what Diamond terms a kleptocracy—rule by thieves. Societies of this kind readily take over other societies by means of conquest.
Reflecting on all this, Diamond concludes that the differences in wealth and power that exist in the world today are not due to any inherent superiority on the part of the more successful peoples but arise instead from geographical and other differences in the environments in which the different groups chanced to find themselves. Tracing the consequences of these differences is a complicated matter but, even so, Diamond is aware that he may be criticized for over-simplifying. As he says, this is inevitable; you can't squeeze 13,000 years of history on all continents into 400 pages without some simplification, and some questions remain unanswered. He acknowledges the difficulty and uncertainties inherent in trying to establish something resembling a science of history, but he is persuaded that progress in understanding history is possible.
This is a book that will probably annoy professional historians, who will not be backward in objecting to some of Diamond's statements in their own fields of expertise. This is the fate that awaits any generalist. Nevertheless, he was surely right to make the attempt, and I think it is difficult to refute the main thrust of his argument. The book is highly readable and entertainingly written; it is also full of facts, some very surprising. It should be widely read.