That we are in dire need of new planetary thinking and political action, at a variety of scales, is by now perhaps indisputable. In a book both sweeping in scope and generatively unsettling, Thomas Nail sets out no less than a Theory of the Earth, a title borrowed from James Hutton’s eighteenth-century geo-philosophical treatise of the same name, brought forward to address twenty-first-century issues. It is part of a burgeoning field of work around geological thought, deep time, and planetary scale that draws seemingly unlikely connections between the deepest strata of Earth and contemporary developments in politics, economy, and identity. Mining this deep vein, this book makes a philosophical argument at one of the largest scales that human thought can operate on— that of the planetary, all the way from its molten core to the brittle mantle where all life exists and human history is just a blip—all situated in broader patterns, motion, and energy expenditures of the cosmos. Rather than as a static earth on which humans and their mobility-driven systems of transport, economy, and migration exist, Nail argues, we need to understand the Earth as fully and constitutively in motion, and human actions therefore as part of a mobile earth: a kinetic planet in need of a new kinetic ethics.

The book makes this case in well-structured parts on theory, history, and ethics. Drawing both on various strands of process philosophy and on earth systems science, the first part proposes a theory of geokinetics, arguing that the Earth is not a thing but a mobile entity or a “process of terrestrialization” all the way down (p. 20), composed of flows, folds, and fields. What seems like the stable matter of the planet, in other words, is itself fully in motion: the soil of the Earth, for example, is itself the place where other spheres (biosphere, hydrosphere, atmosphere) “break down, comingle, mix, and coproduce each other.” These planetary flows affect one another in periodic cycles (p. 41), and in turn, these cycles have periodic stabilities or fields. In short, the first part translates and reframes the core of earth system sciences into the basic building blocks of a process philosophy.

In the second part on history, the book makes a stronger claim: the Earth is itself historical. In other words, long confined to the study of human action, the very geokinetic processes of the planet—whether the compositions of rock strata or the emergence of water, lightning, or atmospheres as phenomena— should be understood as also historical. As a result, Nail argues that deep geological pasts are not just background for the present day: they are the present day (p. 62). The part goes on to explore various processes of mineralization, atmospheres, vegetality, and animality—all as part of the historical-kinetic processes of the planet and therefore also a history of the present moment. Humans may have inadvertently stumbled into becoming geological agents, as Dipesh Chakrabarty has recently argued (The Climate of History in a Planetary Age, 2021), but the planet has long had historical agency. The upshot is that an analysis of climate ethics and politics needs to rethink itself from the (moving) ground upward to understand the ways that human actions contribute or detract from the intersecting elements of this larger planetary history.

In the third, concluding part, Nail leverages the apparatus of thought from the first two sections to think about what this might imply for earth ethics. Provocatively, for example, one of the key arguments is that we should understand fossil fuel capitalism not as wasting too much energy or using too much, but actually as not wasting enough of the right kind or in the right way. By deeply disrupting the Earth’s carbon cycles of energy dissipation, founded in the energy intake/release activities of trees and other biotas, fossil fuel culture (and what Nail calls the “fossil fuel classes”) interrupts what is ultimately a planetary imperative: to participate in the meaningful expenditure of energy in the universe. His suggestion, then, if humanity is to survive, is to find ways to increase planetary energy expenditure (in the right ways, of course). This is a useful way to move away from some of the politics and language of conservation that have long been part of the environmentalist lexicon, with a focus on stasis and preservation. Discussion of composting and reciprocity is equally interesting.

The book is full of brilliant reframings from which both political thought and studies of empirical practice concerned with the planetary might well draw. Particularly useful is its insistence that human life emerges from and continues to be a part of the Earth—without reducing human life to a static, mechanistic “natural” being as has been done for so long, in so many ways, to bootstrap the uniqueness of the human (and the uniqueness of human political action in particular) into being. Nail then asks a difficult question: What would it mean to reconsider human ethics and politics as terrestrial and geological formations?

Indeed as Nail argues, Western thought and practice have for too long treated the Earth as an inert substance lacking in genuine novelty; this has left it unprepared to deal—in both the short and long run—with the pressing challenges of the Anthropocene, whether climate change, biodiversity extinction, or the transformation of land, habitats, and basic earth processes. This resonates with the growing sense that politics arguably needs to be looked at not only in its institutionalized basis in the centers of nation-states and other human social formations but also with respect to techno- and bio-networks of material existence at multiple scales. Nail’s book prompts us to take a wider view of the entities and processes that constitute political community and the relations between them, as indeed many nonwestern traditions have frequently done.

Although the book’s treatment of anthropocentrism is coherently critiqued and re-rendered in kinetic terms, it is nonetheless largely a philosophical anthropocentrism focused on the biological human as a species that is the target of both the critique and the reconstruction—and not a political account of anthropocentrism that intermixes more deeply with complicated histories of colonialism, empire, industrialization and extraction, political bordering, and modernization. The question of the forms of life that are valued, killed for, or protected is not always—indeed, is rarely—addressed at the species level but is embedded in political ideologies and histories. The book touches on these more political issues but does not tend to treat them directly.

Theory of the Earth will nonetheless be of wide interest not only to those working in global environmental politics and environmental political theory but also to all those wishing to fully think through what the Earth on which all politics takes place is actually about.