I would like to thank Nicholas Onuf for his generous and probing review. I am particularly taken by how perceptively Onuf characterizes the central impulses of the book: It is inspired by Foucault, but it seeks to provide a macro-historical account of international orders that meets the demands of contemporary social science theory. Indeed, I hope the book reflects my diverse engagements with mainstream international relations theory, critical theory, the history of science, and other traditions. I do not have the space to respond to all of his excellent points, so I will just address what I see as the central issues raised by his review.

As Onuf notes, the book is focused on explaining change in what I call state purposes: the ends to which state power is expected to be deployed. In particular, the book aims to account for the emergence of economic growth as a central purpose in international order today by tracing it to precursors in colonial ideas about development and the notion of improvement that was embedded in balance-of-power discourses. The focus on the story of growth helps to explain some of the omissions he mentions. I do not systematically compare the importance of growth, development, and improvement to security purposes. Rather, I seek to show how cosmological changes provided the necessary conceptual material for the emergence of growth, development, and improvement. So, while I would have liked to discuss a variety of other cosmological themes and scientific ideas, that would have complicated an already baroque narrative.

Onuf questions the role of agency in my model. I accept the point that my book does not adequately capture human agency in its fullness, but I would not say that it drops out. The goal of the book is to show both agency and structure in motion, and thereby to fold the insights of recent work on practice and process into a structural, macro-historical account. To achieve this, the book moves back and forth between macro-level snapshots of international order (through discursive analysis of central conferences and international organizations) and a careful analysis of meso-level case studies. The goal is that the case studies reveal how specific individuals (Metternich, Malinowski, and McNamara, inter alia) actually deployed new cosmological ideas and purposes. So I do not think it is right to say that I allow discursive change to drive change at the meso level. It is the concrete practices of individuals that combine and recombine cosmological ideas in creative ways to produce new ideas and purposes (p. 49). Thus, I believe it is necessary to put the micro, meso, and macro in systematic relation to one another if we are to produce long durée histories of the international order that provide a sense of contingency, while nonetheless recognizing that human agency is constrained by deep changes in how we think about the world and our place in the universe.