Emanuel Adler has been thinking about cognitive evolution, collective meaning, and social construction for a very long time. This book represents a major statement of his mature views, a kind of theoretical summation of decades of scholarship. Rather than providing detailed case investigations, Adler organizes this very conceptual book around three recurrent empirical examples—European integration, cyberspace, and the invention of the corporation—that he uses to illustrate the mechanisms and processes that make up his theoretical account. Suggestive rather than exhaustive, these examples serve as ways of making the book’s abstract architecture somewhat more concrete.

It is impossible to provide a short summary of that architecture, which involves “three sociostructrual processual mechanisms” (p. 28) and “four agential processual mechanisms” (p. 29) that combine and concatenate in an evolutionary way. But the result is clear: it draws a picture of human social action as involved in the selective retention and creative variation of “symbolic, material, and organizational resources” arranged in “competent performances” (p. 217). Adler extends the core constructivist insight—that the world we have is not inevitable, that it did not have to turn out as it in fact did—far beyond the all-too-typical resort to ideational variables; he locates the stability of the world we have not in beliefs and not in structures but in ongoing patterns of practice. It is significant that he calls the book “world ordering,” and not world order; much as in Nicholas Onuf’s work (especially his World of Our Making: Rules and Rule in Social Theory and International Relations, 1989), the ordered, stabilized character of social relations at a particular time and place is an achievement to be explained, not a factor that can do the explaining.

For Adler, order comes from ordering, and “social orders are therefore what communities of practice have learned to become” (p. 123). This means both that social order is held in place by ongoing practices that keep variation within acceptable limits, and that changes in that order must come from the community learning—by selectively retaining novel practices—to be something else. This is perhaps clearest in his discussion of the EU’s acquis communitaire (pp. 168–72), where he makes the point that what is acquired when a country accedes to the European Union is not only a mass of regulations but also a whole bundle of practices. In effect, that country “learns to Europe,” because the European social order is sustained by a set of practices that actors engage in, not merely by formal codes into which actors would have to be socialized.

There is some ambiguity in the way that Adler treats “order,” however. If a social order is held in place by ongoing practices and thus only remains “metastable”—Adler is clear that “social orders are in a permanent state of nonequilibrium” (p. 32), and as such, stability is not uniformity but is variation with limits—as long as it is practiced, then it is unclear just what a social order is and why referring to a temporary fixity as an “order” makes any sense. A more thoroughly relational ontology might instead say this: here is a relative stability in patterns of transaction, but to call it an “order” would be to invest it with too much dispositional weight. (Certainly the actors themselves might call such a relative stability an “order,” as part of their ongoing practice of sustaining that relative stability, but it is unclear why we ought to adopt their language.) Adler never provides an operational definition of an order, and he gives us no way to measure whether one even exists; absent such a definition, it is difficult to assess his relatively optimistic appraisal of the EU’s resilience in the face of a resurgent populism and the rise of “illiberal democracy” (pp. 262–63). In fact, the very idea of appraising an order’s capacity prospectively or in real time seems in tension with the evolutionary thrust of Adler’s argument. Although we could say in retrospect that a community of practice learned to order differently, it is difficult if not impossible to distinguish between an analytical claim about the present and a pious hope that things will turn out a certain way.

Similar ambiguities haunt Adler’s contention that practices survive and are retained through their “epistemic practical authority.” He argues that organized slavery ended because “slavery practices lost their deontic power and anti-slavery practices acquired epistemic practical authority” (p. 270). Yet it is unclear whether this means that varying amounts of epistemic practical authority are the drivers of that process or are endogenous to it. If the latter, then it is unclear how saying that a practice has epistemic practical authority differs from saying that the practice is prevalent. But if it is the former, then we would need some way of assessing or measuring how much epistemic practical authority a practice had, but this is precisely what we cannot do inasmuch as epistemic practical authority is something that the community is constantly (re)negotiating in practice. Here again, we see some conceptual tension between Adler’s admirably relational intention and a substantialist way of speaking of the components of social life. Although the latter approach lends itself to a certain kind of theorizing, it comes at the cost of some ontological inconsistency.

But such consistency has never been Adler’s primary analytical goal. He has consistently advocated a “middle ground” in his work over the years, and he admits to an “aversion to dichotomies” (p. 279) in the final chapter of this book. Instead of either/or, Adler invariably presents us with both/and: material and ideational elements, agents and structures, and, in this book, ordering practices and orders. The resulting richness in directing our attention to a variety of factors that can “explain the creative variation and selective retention of social orders” (p. 25) produces a subtle displacement in the notion of “explanation” that Adler’s sustained focus on theory does not really acknowledge, because it is a methodological displacement. To explain with the conceptual tools that Adler has developed would likely point in a configurational direction, replacing any overarching direction with a careful specification of how elements combine to generate outcomes. That in turn would be in tension with the commitment to progress—even bounded progress—that is on display especially in the book’s closing chapters, but here again, Adler does not want us to choose: once again, the answer is both/and.

And perhaps this is the most important thing that a theory that takes learning seriously can do: if the lessons we learn and the practices that we selectively retain shape the future in which we will live, the challenge of retaining both an awareness of contingency and a commitment to progress may serve as a spur to greater learning. Cognitive evolution may not have a final goal—no evolutionary process does—but it might have a direction if we practice it well.