The search for a paradigm that informs our understanding of global history has concentrated on fashioning a unifying vision or organizing principle that scholars can use not only to describe an enormous variety and number of events, but also to explain how these events were connected to each other and how they fit into some larger picture of the past. Some scholars have emphasized human social inventions, such as states, empires, religious faiths, economic institutions, or cultural practices. Others have based their inquiry on a more materialistic foundation, emphasizing geography, climate, the biosphere (interpreted broadly to include food and disease), human genetics, or energy flows. A third group has focused on the interaction between these two domains, emphasizing the ways in which humans have manipulated their material surroundings by means of technologies such as stone tools, the lateen sail, the steam engine, or the integrated circuit. As one might surmise from the book's title, Jared Diamond's Guns, Germs, and Steel is an example of this last category; two-thirds of the study is concerned with human interactions with the environment via technologies. But Diamond's intellectual range is so wide that the materialist foundation (germs) also bulks large in the book. Even the cultural inventions of the first category are addressed, although they are clearly of less weight in Diamond's opinion, being more derivative than foundational.
The central theme of Diamond's book is that the course of history has been different for different populations not because of any differences among peoples, but because of differences among their physical environments. Evolution through natural selection is the principal driving force, at least at the beginning of the story, 13,000 years ago. The [End Page 203] climate of the Mediterranean (cold, wet winters and hot, dry summers) selected for certain wild grasses (einkorn and emmer wheat) that stored much of their energy in large seeds; these grasses became the basis for the launching of the neolithic revolution some ten millennia ago in eastern Turkey. Humans found abundant nourishment in these seeds, as did other animals—the grazing herbivores like horses, cattle, and sheep—which then became the foundation for a livestock food system. Eurasia's dominant east-west axis offered channels for the expansion (and refinement through adaptation) of this food system across the "World Continent," the grazing animals offered the potential for a portable protein supply, and the domestication of the horse in the Ukraine provided humans with a mobility unsurpassed until the appearance of the steam engine.
The Mediterranean food system, based on wheat, beef, and olive oil, sustained expansive and creative empires. The proximity of humans and animals brought people into closer contact with the animals' microscopic companions and thus enabled Eurasians to evolve defenses against diseases unknown to other peoples of the world. These advantages in climate, mobility, and food energy paid off in advantages in technology (guns and steel) and the institutions they made possible: writing, commerce, statecraft, warfare, and so forth. Two important dimensions of global history emerged from this cluster of advantages: when peoples expanded to other lands, it was the Europeans who didmost of the expanding; when they encountered other peoples andwhen violent conflict ensued, it was usually the Europeans who triumphed (at least in the short run—and the "short run" might last several centuries).
Diamond's treatment of the meeting between the Spanish adventurer Francisco Pizarro and the Inca emperor Atahuallpa shows his paradigm at work. In November 1532 Pizarro and his force of 168 soldiers (described by Diamond as "a ragtag group") entered the Peruvian highland town of Cajamarca and encountered there Atahuallpa, absolute ruler of the largest and most advanced state in the Western Hemisphere. The tiny Spanish force was outnumbered nearly 500 to 1 by Atahuallpa's army, which had recently won a war with another indigenous people. Pizarro was in unfamiliar terrain, cut off from reinforcements, and ignorant of the local inhabitants. Despite these apparently insurmountable obstacles, Pizarro still managed to capture Atahuallpa in a matter of hours, hold him for ransom for eight months, and execute him despite the payment of the ransom.
Why, asks Diamond, did history work out this way? Why did not Atahuallpa send an Incan expeditionary force to Europe, land in Iberia, [End Page 204] and seize Pizarro's ruler, King Charles I? The answers, in his view, lie in the complex of animals, plants, food supply, diseases, transport technologies, and weapons, and the political, religious, and economic institutions that supported (and were supported by) all these things. Pizarro and his force were simply the tiniest of points on a lance that stretched far back across the Atlantic, and even further back in time. They were part of a huge biological, technological, institutional, and cultural system that had several advantages over the native Incan systems. These advantages enabled Spain to project its power over great distances and to deploy it to great effect against resistance. In the language of the systems paradigm, we would say that Pizarro's system possessed much greater "thermodynamic efficiency" than did Atahuallpa's. (To his great credit, Diamond avoids such jargon and writes in a much more straightforward style than does this reviewer.)
This book will not appeal to all readers, particularly if they are put off by the materialist approach to history. Personally, I find such an approach quite illuminating, principally because it reveals in such detail exactly how the natural world (in this case, the biosphere) places limits on the range of choices we confront. This is not the same as saying that biology (or geography, or any other material factor) determines the course of human history; only that such factors preselect for us the alternatives from which we may choose.
