Jared Diamond is a biogeographer and evolutionary psychologist who teaches at UCLA. His 1999 book Guns, Germs, and Steel explained the modern dominance of societies in Europe and Asia over the rest of the world as a consequence of their historical head start in developing agriculture, which in turn, he argues, was a consequence of a few accidental environmental variables such as what plants and animals suitable for domestication were found there. He put forth this argument in explicit opposition to racist explanations of why some societies are more advanced: "History followed different courses for different peoples because of differences among peoples' environments, not because of biological differences among peoples themselves."
And not because of differences in culture: Diamond is a materialist. But as a pre-Marxist materialist, he explains social development from physical conditions directly. So, for instance, in Guns, Germs and Steel he argues that the institution of the state came about historically as a function of population growth. He notices that while nomadic hunting-and-gathering societies are organized into tribes and clans without a specialized ruling apparatus, settled agricultural societies all have states, and asks why this is. His answer is that agriculture allows a society to produce more food and support a larger population, and as the population increases above a certain threshold, you need a state to resolve conflicts between unrelated strangers, regulate exchanges, and to make decisions for the society as a whole.
This analysis leaves out what to a Marxist is most basic: the class struggle. Intensified food production does not merely support the subsistence of a larger population. It also enables a segment of the population to live on the food produced by others. But people don’t work for other people without, at least somewhere in the background, the threat of force--and that is where the state comes in. It’s not an adaptation of society as a whole, as Diamond presents it to be, but rather the weapon that a group within society must use against those they subordinate and exploit.
Marxists understand that human development is not a direct adaptation to natural conditions but is always mediated by social relations, especially those that organize production. Coincidentally, Diamond’s mechanical, pre-Marxist materialism may in fact work well enough for the period crucial to his central argument in Guns, Germs, and Steel--the one leading up to the development of agriculture, before there was enough extra food to support a thoroughgoing division of labor.
But when he turns his attention to class societies, the consequences of this approach are more debilitating, as can be seen from the odd remarks on the South Asian caste system in his recent book, Collapse.
Subtitled “How Societies Choose to Fail or Succeed,” Collapse presents a series of environmentalist morality tales: cases of societies across the world and throughout history which either failed/are failing to manage their resources properly and suffered/will soon suffer the consequences, or succeeded in doing so and prospered. Those judged successes include examples of both “top-down” ecological management directed by a strong central government (the Incan slave empire, caste-feudal Tokugawa Japan) as well as “bottom-up” initiatives based on the enlightened self-interest of a community of small proprietors (as on the tiny Polynesian island of Tikopia). Having listed several of the latter variety, Diamond writes:
Each of these cases of bottom-up management that I have just mentioned involves a small society holding exclusive rights to all economic activities on its lands. Interesting and more complex cases exist (or traditionally existed) on the Indian subcontinent, where the caste system instead operates to permit dozens of economically specialized sub-societies to share the same geographic area by carrying out different economic activities. Castes trade extensively with each other and often live in the same village but are endogamous--i.e., people generally marry within their caste. Castes coexist by exploiting different environmental resources and lifestyles, such as by fishing, farming, herding, and hunting/gathering. There is even finer specialization, e.g., with multiple castes of fishermen fishing by different methods in different types of waters. As in the case of Tikopians and of the Tokugawa Japanese, members of the specialized Indian castes know that they can count on only a circumscribed resource base to maintain themselves, but they expect to pass those resources on to their children. Those conditions have fostered the acceptance of very detailed societal norms by which members of a given caste ensure that they are exploiting their resources sustainably.
Diamond interestingly represents the caste system as a mutually benefiting network of autonomous collectives, a kind of ecologically responsible anarchist utopia. He talks of castes as independent "sub-societies" which “trade extensively with each other” on a presumably equal footing. By exploiting their own specialized, well-managed niches they’re able to coexist harmoniously in the same territory and "often,” he writes, “...in the same village"--as though castes ever lived in their own separate villages.
The truth is that caste emerges from a class-based division of labor within a village. The typical, traditional arrangement in an Indian village is like this (or was--things have changed over the past fifty years, though not completely or fundamentally, and not in ways that have brought much social progress). There is a dominant, landowning family (or several families, depending on the size of the village) belonging to a high caste. Most of the other families in the village (the lower castes--sudras and untouchables) are hereditary servants of that dominant family. They are weavers, potters, agricultural laborers, butchers, barbers, basket makers, bangle-sellers, and so on--the very name of their caste is usually the same as the word for the occupation they follow. For these services they receive a customary payment from their patron, generally a set portion of the harvest--or, in some cases, no compensation at all. The service castes also trade among themselves, but they are obliged to the dominant family and must satisfy their duties to it first. There may be other families who own some land and work it themselves, but the main product of the village is the crop raised by the laboring castes on the land owned by the dominant family. (In even earlier times, the services of the lower castes were owed not to particular families but to the village as a whole.)
Diamond identifies three defining characteristics of a caste system--endogamy, occupational specialization, and assignment of occupation by birth--but leaves out the fourth: hierarchical ranking by ritual purity. The ritual ranking of castes--based on the class division between the uppercaste landowners and the laboring lower castes--is the ideological justification for the village-based system of exploitation described above (called the jajmani system). This ideology is so important for the functioning of the system that its propagandists, the priestly castes, the brahmins--even though they are in fact service castes whose duty is to see to the ceremonial needs of a dominant family--are assigned the highest ritual rank.
So rather than being an equitable, “bottom-up” way of optimally "exploiting different environmental resources," the caste system is actually a way of exploiting other people's labor. Human labor is one resource that no society can do without, and, though Diamond doesn't mention it, it's the one the caste system actually exists to manage. Not equitably but in the first place in the interest of the owners of the means of production, and optimally only relative to that archaic stage of development.
It’s also worth noting that not all caste-defined niches are equally hard to manage sustainably. The human shit and animal carcasses that it is the lot of those born into untouchable scavenger castes to carry off manually are in little danger, unfortunately, of ever becoming depleted.
As for the book’s main message, within the fundamentally anarchic capitalist world market no one has the ability to make rational, socially responsible decisions about how resources are used, neither individual firms nor national governments (no matter how many high-minded international treaties they sign). Societies will be able to “choose to fail or succeed” only when they can organize production for the collective good.