An old adage among skeptics is that there are no straight lines in nature—that is, unless we define what we mean by a line, and more importantly, who gets to say so. In Who Speaks for Nature? Laura Ephraim has penned an engrossing narrative fundamentally concerned with the implications of that basic anecdote, providing a profoundly ambitious answer to it with implications for political theory’s place in the politics of science. Drawing from a wide range of intellectual registers—postpositivism, new materialist thought, and the aesthetic turn in political theory—the work exhibits the breadth of Ephraim’s knowledge of debates in political science, science and technology studies, and the history of ideas as they concern the vital investments that scholars make in shaping science.

After a substantive introduction, Ephraim begins with the distinction between earth and world illustrated by Hannah Arendt in The Human Condition (1958, Chapter 1) and the “tensions between her vision of politics and the two-sciences settlement” (p. 35). Chapter 2 turns to Giambattista Vico, recovering his view of politics as “the historical creation of a world of relationships among the diverse phenomena given by nature” (p. 69). In Chapter 3, Ephraim takes on the contested legacies of René Descartes as the target of so much repudiation concerning the modern scientific imagination, focusing on “the role of aphorism, dialogue, and fable in his corpus” and linking these to latent “democratic leanings overlooked in familiar Enlightenment affirmations as well as democratic costs overlooked in familiar contemporary criticisms” (p. 93). Lastly, Ephraim turns to Thomas Hobbes (Chapter 4) in order to lay bare how the “act of knowing, for Hobbes, was a continuation of the act of making,” giving rhetoric a central place in “constructing foundations, not just façades, for [his] new science” (p. 119). The book ends with an urgent meditation on the dangers of climate denial and the need to “make science more, not less, political . . . in order to respond to the most consequential ecological and political problems of our time” (p. 143).

Ephraim’s inspiration is the contentious relationship between the natural sciences and the contrasting aims of social movements that buttress or contest scientific authority in the face of global climate change. The conflict revolves around what she calls “the aura of inevitability surrounding the authority of the natural sciences,” which she seeks to dispel by “interrogating [its] political origins, sources, and limits” (p. 2). While the “science question” in political theory has been dealt with from vastly different epistemological standpoints, Ephraim repositions politics into this conversation as “an enabling condition for scientists to do what they do when they speak for nature” (p. 3). The everyday life of scientists as “spokespersons” for nature offers her an opportunity to explore how the material and procedural networks informing scientific activity “compose a common world” (p. 4) from an otherwise allegedly passive set of heterogeneous atoms, instruments, and vernaculars.

Although there are plenty of engagements by political theorists with the politics of nature, few have taken on the role of science in this equation with the nuance that Ephraim employs. She shows that although science has no timeless altar, its logic of founding and refounding rests on a wellspring of “common sense” that makes the world legible and hence a domain of political discourse (p. 7). It just so happens that our current definitions of politics and discourse will not acknowledge that basis. Despite great advances in the ways in which political theorists today interrogate materiality, authority, and even concept formation, it is the lack of sustained scholarly attention to the paradoxes of science as a political activity that Ephraim engages. By prioritizing “intra- and intertextual interpretation ahead of contextualization,” she turns to the past “to defamiliarize and reexamine the dynamics of the present” (p. 10), in turn rethinking the deeply contested nature of science as both discursive and corporeal in scope, subject to (and productive of) wide-ranging political agendas.

Focusing on what she aptly describes as the “two-sciences settlement” (pp. 10–18)—echoing historian C. P. Snow’s concerns in The Two Cultures (1959) over the distinct missions of “science” and the “humanities”—Ephraim diagnoses political theory as ill-equipped to take seriously the distinct ways that scientists and their objects make up our world (p. 17). In this spirit, Who Speaks for Nature? is a timely intervention that takes a burgeoning interest in nonhuman activity and links it to the ever-changing bases on which claims to knowledge and political authority are made. Indeed, the book reminds political theorists in the dark times of “fake news” that the dispute concerning legitimate knowledge is not political because there are distinct visions at stake, but rather because the rhetorical, physical, and interstitial constitution of our world “is a particularly consequential way of organizing collective, affective encounters among human and nonhuman bodies” (p. 29). Our world is made and remade through the ways in which scientific practice is debated, defined, and delimited.

Within the history of political thought itself, there remains a dramatic dearth of work engaging the intersections of science, nature, and epistemology. This is especially glaring, as Ephraim points out, given the politicization and political stakes behind the intensification of climate change, but also the transformative (and often obfuscating) character of concepts such as the Anthropocene. Though Ephraim speaks valiantly to the efforts of luminaries in the history of ideas who have in their own ways drawn attention to the sensuous and aesthetic construction of scientific authority, the book is more about science than it is about nature. That by itself is not bad, as she masterfully dissects the links between philosophical rhetoric and the material circumstances that shape scientific authority and vice versa. Throughout my reading, however, I often wondered what role the study of natural history plays in that very materiality. Particularly absent is the kind of natural history practiced over time by missionaries, field experts, and indigenous peoples. In a more provocative sense, who exactly speaks for science in Ephraim’s accounting of things?

Nevertheless, for historians of political thought, Ephraim’s inverted chronology—counterintuitively moving backwards from an initial chapter on Arendt, followed by readings of Vico, Descartes, and Hobbes—offers a vivid portrait of what Mark Bevir’s The Logic of the History of Ideas (1999) describes as “synchronic” and “diachronic” analysis: clarifying each thinker’s historical context while unpacking her own evolving sense of the politics of scientific authority. Moreover, putting the history of political thought into conversation with developments in new materialism is an especially welcome (and impressive) achievement, as the former often suffers from linguistic biases that Ephraim so ably criticizes, and the latter regularly lacks the historiographical and empirical nuance provided by close textual analysis.

The strength of Who Speaks for Nature? is twofold: On the one hand, Ephraim’s ability to cover critical perspectives on the life, thought, and legacies of scientific theories over the course of almost four hundred years is thorough and impressive, not least for a book of this size. Environmental political theorists, as much as historians of science and empire, would gain significantly from the author’s thoughtful prose and incisive analyses.

On the other hand, the future of science in an era of deep climate skepticism is noticeably important for Ephraim, not just for the obvious consequences of a runaway Mothership Earth but for the very vibrancy of our democratic politics. The text displays an adept ability to weave aesthetics and politics into a mutually enlightening critical reflection, shining light on today’s epistemological polemics but also cutting through the intransigence of science defenders and deniers alike in order to reveal the political stakes for all. As its brief epilogue conveys, who speaks for nature is a matter of life and death for so many in our world, “a crisis in the very fabric of reality” (p. 144). In sum, the book highlights not only how the conceptual distance between two points is hardly ever a straight line but also how the circuitous journey is precisely what makes the process worthwhile.