Introduction
Jared Diamond's "Guns, Germs and Steel" takes on an ambitious task: explaining the broad patterns of human history over the past 13,000 years. As a biologist, geographer, and historian, Diamond zooms out to a scale far beyond most historical works, seeking to understand why human societies developed so differently across the globe.
The book's central question is both simple and profound: Why did some societies advance technologically and politically, while others remained hunter-gatherers? More specifically, why did Eurasian civilizations come to dominate the world, rather than African, American, or Australian societies?
Diamond's answer is complex, but at its core lies a fascinating exploration of how geography shaped the development of agriculture, and how agriculture in turn shaped the course of human history.
The Great Divergence
To understand Diamond's argument, we need to travel back in time to around 11,000 BCE. At this point in history, human societies around the world were remarkably similar. Whether in Peru, Poland, or Papua New Guinea, people lived as hunter-gatherers, using stone tools and lacking written language.
Fast forward to 1492, the year of Columbus's first voyage to the Americas, and the picture looks radically different. While some parts of the world still relied on hunter-gatherer lifestyles, Eurasia (the landmass stretching from Europe to Japan) had developed complex civilizations with state governments, writing systems, iron tools, and powerful armies.
This divergence in human development is the central mystery that Diamond sets out to solve. Why did some societies advance so much more rapidly than others? And why was it Eurasians who ended up conquering much of the world, rather than the other way around?
The Power of Agriculture
At the heart of Diamond's explanation lies a simple but crucial factor: agriculture. The ability to produce food surpluses through farming is what makes complex human societies possible. When a society can grow more food than it needs for immediate consumption, it can support people who don't work the land – like artisans, soldiers, priests, and rulers.
This surplus is what allows for the development of cities, which Diamond sees as crucial incubators of civilization. Cities bring people together, fostering innovation and competition. They also, somewhat counterintuitively, help societies develop resistance to diseases. By crowding people together, cities create environments where diseases can spread rapidly, but this exposure ultimately leads to stronger immunity for the population as a whole.
The combination of technological innovation, political organization, and disease resistance that emerges from agricultural societies is what Diamond refers to as "guns, germs, and steel" – the tools that allowed some societies to dominate others.
The Fertile Crescent: Cradle of Agriculture
To understand why some societies developed agriculture earlier than others, Diamond takes us to the Fertile Crescent – a region stretching from modern-day Turkey through the Levant and down into Iraq. This area, with its rich soils and diverse plant and animal life, was the birthplace of agriculture around 12,000 years ago.
In the Fertile Crescent, early humans began deliberately planting wild grasses with large, nutritious seeds – the ancestors of wheat and barley. Over time, they added other crops like lentils, olives, figs, and chickpeas. They also began domesticating animals, starting with cattle, sheep, pigs, and goats.
This agricultural revolution laid the foundation for the first cities, which began to appear around 7,500 BCE. These early urban centers relied on the food produced by this new way of life, setting the stage for the development of complex civilizations.
The Importance of Geography
While the Fertile Crescent was the first center of agriculture, it wasn't the only one. China developed its own agricultural package based on rice and soy, while in Mexico, people cultivated maize, beans, tomatoes, and squash. However, not all regions were equally blessed with potential crops and domesticable animals.
Sub-Saharan Africa, for instance, had some useful crops like millet and yams, but these plants didn't naturally grow in the same areas, making it harder to develop a comprehensive agricultural package. Large African mammals, which might have been useful for domestication, proved too difficult to tame.
But the real key to understanding the divergence of human societies, according to Diamond, lies in the diffusion of agricultural practices. This is where Eurasia had a unique advantage.
Eurasia's East-West Advantage
The Eurasian landmass is unique in that it's oriented along an east-west axis. This means that most of its fertile regions lie at roughly the same latitude, resulting in similar day lengths and seasonal patterns across vast distances.
This geographical quirk had profound implications for the spread of agriculture. Crops that thrived in one region of Eurasia could often be successfully transplanted to other areas thousands of miles away. For example, wheat could be grown just as easily in France as in China, despite the enormous distance between these regions.
This ease of crop diffusion allowed Eurasian societies to rapidly exchange agricultural innovations, diversify their food supplies, and support larger, more complex civilizations. The sharing of crops and livestock across Eurasia created a positive feedback loop, accelerating the development of technology and social organization.
The North-South Challenge
In contrast to Eurasia, the Americas and Africa are oriented along north-south axes. This orientation spans many different latitudes, resulting in significant variations in day length and seasonal patterns between regions.
This geographical reality made it much more difficult for crops to spread. A plant that thrives in Mexico, for instance, would need to undergo significant genetic adaptation before it could be successfully grown in Peru. This slowed down the diffusion of agricultural practices and, by extension, the development of complex societies in these regions.
Diamond uses the example of maize (corn) to illustrate this point. Maize was first domesticated in Mexico around 6,000 BCE, but it took thousands of years to adapt it for cultivation in North America and South America. This slow spread of agriculture meant that societies in the Americas had less time to develop the complex technologies and social structures that characterized Eurasian civilizations.
The Compounding of Advantages
The early development of agriculture in Eurasia set off a chain reaction of advantages that compounded over time. By 2,500 BCE, societies in the Fertile Crescent had already developed metal tools, centralized states, and writing systems. These innovations gave Eurasian societies a significant head start over other regions of the world.
This head start meant that when agricultural revolutions finally did occur in Africa and the Americas, Eurasian societies were already far ahead technologically and organizationally. By the time of European exploration and colonization, Eurasian states had developed oceangoing ships, firearms, and complex political systems that allowed them to project power across the globe.
Guns, Germs, and Steel in Action
The Spanish conquest of the Inca Empire provides a vivid illustration of how the advantages developed by Eurasian societies played out in practice. The Spanish conquistadors arrived with several key advantages:
Guns: Firearms, while still primitive by modern standards, gave the Spanish a significant edge in combat.
Steel: Metal weapons and armor were far superior to the stone and wooden weapons used by the Inca.
Horses: Cavalry provided a mobile fighting force that was entirely alien to American societies.
Germs: Perhaps most devastatingly, the Spanish brought diseases like smallpox, to which they had developed some immunity but which ravaged Native American populations.
These advantages, all ultimately stemming from the early development of agriculture in Eurasia, allowed a small number of Spanish soldiers to overthrow an empire of millions.
Beyond Technological Determinism
It's important to note that Diamond's argument is not one of racial or cultural superiority. He emphasizes that the differences in societal development are due to environmental factors, not inherent differences between peoples. Given similar geographical advantages, any human society would likely have developed in similar ways.
Moreover, Diamond is careful to point out that "advanced" does not mean "better" in any moral sense. Many of the technologies developed by complex agricultural societies have had negative impacts on human health and happiness, as well as on the natural environment.
Conclusion: The Long Arc of Human History
"Guns, Germs and Steel" presents a compelling explanation for the broad patterns of human history over the past 13,000 years. By focusing on the fundamental role of agriculture and the geographical factors that influenced its development and spread, Diamond provides a framework for understanding why human societies diverged so dramatically.
The book's central insight – that food surpluses are the prerequisite for the development of complex, technologically advanced societies – helps explain why Eurasian civilizations came to dominate the globe. The unique east-west orientation of the Eurasian landmass facilitated the rapid spread of agricultural innovations, giving societies in this region a crucial head start.
This geographical advantage compounded over time, leading to the development of the "guns, germs, and steel" that allowed Eurasian societies to conquer much of the world. By the time of European exploration and colonization, the die had been cast thousands of years earlier by the quirks of continental geography and the distribution of domesticable plants and animals.
Diamond's work challenges us to think about history on a truly grand scale, considering how the environment shapes human societies over millennia. It also serves as a reminder of the profound impact that agriculture has had on human civilization – an impact that continues to shape our world today.
By understanding these long-term historical processes, we gain valuable insights into the roots of global inequality and the complex interplay between geography, technology, and social organization. While "Guns, Germs and Steel" doesn't provide all the answers, it offers a fascinating perspective on the broad sweep of human history and the factors that have shaped our diverse world.