- Ecological-Evolutionary Theory: Principles and Applications
Pursuing general principles at the broadest scale of societal comparison provides the most ambitious stage on which seekers of a socio-logic of history confront historical particularism. In Ecological-Evolutionary Theory, eminent-emeritus sociologist Gerhard Lenski provides a lucid capstone statement of his own distinguished efforts to draw lessons from features and fates of human societies past and present, large and small. The scope of what Lenski means to address using ecological-evolutionary theory (hereafter EET) can be seen from the four applications provided in the second half of the book: "The Origins and Early Development of Ancient Israel," "The Rise of the West," "Trajectories of Development among Societies," and the failures of "Marxist Societies." While some historians undoubtedly will be distressed to see each of these topics dispatched in about 20 pages, Lenski's endeavor is to understand the patterns visible from exactly such a high-altitude view, and he offers compelling arguments that a larger and explicable structural storyline really does exist in each case.
Indeed, the brevity of the applications belies Lenski's view that a major contribution of EET is that it actually offers a more complicated and nuanced view of society than other theories with similar ambitions. At one point, Lenski presents a very incisive table that compares EET to  other theories in terms of the attention given to six "determinants of social system characteristics (ideologies)." (p. 128) In other words, everything competitors postulate as being important for understanding societal composition and change EET also regards as important – if not always as important – while arguments against particular competitors often turn on their inattention to something EET emphasizes.
EET seems pitched most against those who would give ideas, culture or social organization too much autonomous credit in the determination of history, emphasizing instead the continual exertion of material constraints on societal possibility. Human societies are constrained first by the behavioral dispositions encoded in our genes, then by the available resources in society's physical environments, and finally by the technologies available to extract resources. Genetic constraints are used to explain what humans can do given environmental and technological constraints. Environmental features are invoked to explain differences across societies with similar technological sophistication, while technological change carries the main explanatory weight for explaining social change. Although not a technological determinist, Lenski is an enthusiastic proponent of the centrality of technology for understanding social change. His outline of promising directions for future research is mostly preoccupied with expanding appreciation of the influence of technology, especially in such seemingly idea-centered domains as religion and the arts.
As technology opens up possibilities for social change, human nature is depicted largely as providing inviolable counterweights that keep societal history in check. Sociology's pathological history of histrionic, credibility-torching resistance to even relatively mild invocations of "biology" makes any serious acknowledgment of its importance welcome. Still, arguing that human nature is a necessary part of theories of human society goes nowhere by itself, and the real theoretical work is in articulating a conceptualization of human nature that is both biologically and psychologically accurate and theoretically fecund. Here, Lenski's discussion of human nature is disappointing and devolves mostly into vague axioms: "human action is governed by emotions as well as reason" and "humans economize most of the [End Page 1843] time." (p. 48) Proponents of EET might be better served by closely considering the ideas about the co-evolution of human psychology and society presented in Boyd and Richerson's Not by Genes Alone, which seems otherwise quite resonant with Lenski's thought.
Like many others, Lenski proffers the failures of Marxist societies as the chief cautionary tale about the disciplining of idealistic visions by human nature. Whatever its merits, the cogency of the example is likely less for those younger social scientists who have trouble understanding exactly how so much of the academy took the more utopic flights of Marxism so seriously anyway. Indeed, a larger problem with Lenski's legacy may well be that the world has shifted...