In this rich and ambitious book, Mark Usher asserts that one of our best hopes of responding to our environmental crisis is to re-access the thoughts of the ancients, who anticipate much of what modern scientists and environmentalists claim as original insights. Ancient thinkers draw our attention to our place in environmental systems involving both humans and nonhumans, and to the sorts of “values and practices that are conducive to sustainable living” (p. xi). Paradoxically, then, a reengagement with ancient “Western” writers, given their tendency to recognize the broader contexts of human lives and actions, can serve as an antidote to the damaging parochialism and narrow self-interest of more recent western cultures, which have contributed so much to our current crisis.
A first chapter approaches the themes of systems and sustainability through Albert Schweitzer’s notions of “Reverence for Life” (“Ehrfurcht vor dem Leben”) and “debt” (“Schuld”: the debt incurred when a human being kills another living thing). These concepts are in keeping with a “systems” approach to the natural world, insofar as relationships of indebtedness imply interconnections between humans and nonhumans. Usher applies this notion of debt to ancient myths describing interactions with the natural world, whose interests are represented by (at times vengeful) instantiations of the Great Mother: e.g., Actaeon’s Artemis or Erysichthon’s Demeter.
Chapters 2 and 3 find precursors to modern complexity theory in the Presocratic tradition. Usher compares Anaximander’s apeiron (“boundlessness”?), “a diffuse material substance that functions as both a source and receptacle… of coming-to-be and perishing” (p. 52), with the stuff/matrix underlying phenomena on a quantum scale and explores similarities between Anaximander’s and complexity theorists’ accounts of the development of the cosmos and of life on earth. In both cases, order is said to emerge from chaos without the need for external intervention from, e.g., a divinity. Heraclitus’ concept of “flow” anticipates a quantum universe characterized by processes and becoming, rather than housing discrete objects with fixed properties. Heraclitus’ treatment of opposites (e.g. “The road up, down is one and the same,” p. 51) anticipates Niels Bohr’s notion of “complementarity” – the idea that apparently incompatible (“complementary”) behaviors of phenomena such as light emerge from experimental conditions or, more broadly, are dependent on one’s perspective, rather than being permanent attributes of the phenomena in question.
In the next two chapters, Usher turns to politics. Chapter 4 analyzes the first city described in Plato’s Republic (369b-376e). Though Glaucon dismisses it as a “City for Pigs,” Socrates calls this peaceful, vegetarian community a “true, healthy city” and introduces the state that will form the focus of the rest of the dialogue as “luxurious, feverish” (p. 93). Usher argues that the City for Pigs represents a “model for sustainable living,” exemplifying the sort of “interdependence and conscientious self-restraint” that is a precondition for any such community (p. 108). According to Chapter 5, Athens’ Cleisthenic constitution shows a concern for limits, which provides a necessary basis for political freedoms, political participation and sustainable living.
The following chapters discuss Hellenistic and Roman philosophy. Chapter 6 praises Stoicism for its recommendation of a life in accordance with Nature and for its concept of oikeiōsis which, according to Usher, implies a “concer[n for] the sustainable interaction of individual organisms with their physical ecosystems…” (p. 145). In chapter 7, Usher defines his reading of imperial Roman society against that of Ronald Syme’s Roman Revolution (Oxford, 1939). While Syme emphasized the dominance of a monarchical ruler, Usher proposes that a “Pompeian” republicanism continued into Augustan times, characterized in part by a relatively egalitarian and sustainable attitude to land ownership and agricultural labor. Usher sees such ideals reflected in a small farm in Sabine country, which may have belonged to Pompey and where he now engages in cultivation and archaeological research.
The final sections of the book take the story forward from late antiquity to the present day. Chapter 7 finds continuities between the pagan world of the previous chapters and early Christianity. Usher also praises the communal, work-oriented life of the Benedictine monks and explores medieval and modern successors of such communities, both sacred and secular. An Afterword (pp. 207-16) depicts Usher’s own dedication to sustainable living on his farm in Vermont.
I have two relatively minor concerns. Firstly, the analogies between ancient and modern conceptual systems occasionally seem inexact. We might wonder, for example, whether the absence from the Greek texts that Usher discusses of the sort of complex mathematical modeling associated with the modern science of systems weakens some of the comparisons that he draws in chapters 2 and 3. Secondly, we might question whether it is always possible to separate the deleterious actions of the Greeks and Romans (as cataloged by J. Donald Hughes) from the admirable conceptual systems that Usher’s book uncovers. When Usher focuses on Cleisthenic democracy and asserts its environmental bona fides, it is hard to forget the Athenians’ abuses of humans and the natural environment – as for instance in their harvesting of old-growth forests to provide timber for their fleet or in their exploitation of enslaved workers in their silver mines.
These possible shortcomings are, however, outweighed by the book’s many virtues. As should be clear from the summary above, this is a work of remarkable erudition, displaying a mastery not only of a rich array of ancient philosophers, poets and politicians, but also of modern physics, philosophy, economics, agronomy and theology. Its avowedly essayistic style is a vehicle not for casual sketches but for a prolific celebration of human conceptual achievements, to match the teeming life of the natural world, which is the object of Usher’s passionate advocacy and practice. More importantly, Usher’s thought, rhetoric and way of life offer us models for what (even) we classicists might contribute to solving some of the most urgent problems of our time.
 Usher draws on the German text (1923) that was later translated as Schweitzer’s Philosophy of Civilization, Buffalo: Prometheus Books, 1987.
 Hughes, J. D., Environmental Problems of the Greeks and Romans. 2nd ed. Baltimore: Johns Hopkins University Press, 2014.