A major point that sets Why the West Rules—For Now apart from other presentations of a geographic determinist view of world history is its chronological scope. Rather than starting with the beginning of recorded history or with the origins of settled agricultural societies, Morris begins at a point before the history of homo sapiens as a species. Such an approach can be termed as “longue durée,” literally meaning “long duration."

For Morris, the purpose of such a massive scope is to prove that the East and West “have gone through the same stages of social development in the last fifteen thousand years, in the same order, because they have been peopled by the same kinds of human beings, who generate the same kinds of history” (29-30). At the same time, the approach will show the ways in which “the meaning of geography” (31) changed, specifically how societies at different stages of development react to, and are changed by, geographical factors like climate change.

For Morris, this approach better allows for examining both patterns and changes over large periods of time, as well as answering questions like why the empires of Han China and Rome collapsed but later societies did not when faced with similar challenges of failing agriculture and mass migration. In sum, the longue durée approach shows how some “cities and states succeeded so well that they, too, ran into resource problems and transformed themselves into empires” and then some “of these empires repeated the same cycle, putting pressure on their resources and turning themselves into industrial economies” (559).

In practice, this means examining these patterns and continuities in the overview in order to discover what Morris calls “the shape of history” (25). Morris believes the shape can be discerned quantitatively, meaning through data measuring social development across millennia and multiple societies. While Morris denies that this means that historical outcomes like the rise of the West were ever “locked in” (25), he does believe that his model can be used to anticipate future developments, stating, “I now want to suggest that the same approach can help us see what the elephant will look like a hundred years from now” (590). Nonetheless, Morris also believes that rising social development could lead humanity into totally unpredictable directions, either a civilization-ending apocalypse or a future so technologically advanced that biology and sociology no longer have the same meanings.

However, the only way a longue durée approach, as Morris undertakes it, can work is if it is combined with an interdisciplinary methodology. He writes that for the purposes of Why the West Rules—For Now,“we need a broad approach, combining the historian’s focus on context, the archaeologist’s awareness of the deep past, and the social scientist’s comparative methods” (23-24). For example, archeology, anthropology, and evolutionary biology are important for understanding prehistory while sciences that examine climate and topography are crucial for looking at how geography impacts historical developments. Morris does admit to the limits of his own expertise, admitting that his approach is just the “least bad way to proceed” (24).

Still, Morris must think that historians are capable of adopting such interdisciplinary challenges, since Why The West Won—For Now ends with a rallying call: “Only historians can draw together the grand narrative of social development; only historians can explain the differences that divide humanity and how we can prevent them from destroying us” (622).

Histories that attempt to explain why and how western Europe came to dominate most of the rest of the world in the 19th century through geographical determinism have been accused of offering Eurocentric and racist explanations. Morris is clearly sensitive to such criticisms. He mentions how people who believe in “long-term” theories about the rise of the West are portrayed as “pro-Western apologists or even racists” while, at the same time, scholars who support “long-term” theories accuse those who prefer “short-term” theories of being “politically correct” (21). However, Morris’s own “long-term” theory instead presents a basis for an egalitarian understanding of human nature, offering critiques of cultural and racial explanations for dominance.

In discussing his reasons for delving into the evolutionary histories, Morris writes, “Pronouncing racist theories contemptible is not enough. If we really want to reject them, and to conclude that people (in large groups) really are all much the same, it must be because racist theories are wrong, not just because most of us today do not like them” (50-51). Morris engages with theories concerning different hominid species intermixing with homo sapiens precisely so that he can dispense with the racist implications surrounding some of them.

It is also clear that Morris sees his theory as promoting a more egalitarian view of history by debunking historical claims of both racial and cultural superiority. Morris’s theory of social development depends on the idea that “biological and sociological laws are constants, applying everywhere, in all times and all places” (29). It follows from there that “[p]eople, in large groups, are much the same wherever we find them, and we have all inherited the same restless, inventive minds from our African ancestors” (73).

Looking at data on the rate of agricultural production and cultural developments like pottery “strongly suggests that developments in the East and West shared a cultural logic, with the same causes having the same consequences at both ends of Eurasia. The only real difference is that the process started two thousand years earlier in the West” (131). In essence, all cultures and societies are the same. The only real difference is that geographical circumstances drive social progress at different rates.

Not only is Morris arguing that the concept of cultural and biological superiority or inferiority have no grounding in either history or science, he also suggests that the historical differences that are cited to prove one society’s inferiority or superiority are effectively just because of happenstance.