Perhaps the most familiar of the Victorian pseudosciences, phrenology posits that the mind shapes the brain and the brain shapes the skull. Any individual's character, therefore, can be “read” by studying the shape of their head. Broadly deployed, extremely popular and widely discussed throughout the nineteenth century, it is perhaps unsurprising that phrenology already occupies a fairly well-explored area in the history of science. This valuable and engaging book, however, breaks new scholarly ground. James Poskett uses the material cultures of phrenology—such as skulls, letters, and photography—to generate an interconnected transnational history that transforms a familiar pseudoscience into a complex and multifaceted global process. As it examines phrenology's many global pathways, interchanges and permutations, Materials of the Mind remains attuned to power but explicitly works against the constraints imposed by units of analysis such as nations and empires, offering instead a materially based and iterative model for a global history of science.

As a global history, this work offers a wide-ranging and erudite analysis of how transnational flows of material and material cultures shaped phrenology. Astutely avoiding both linear chronology and fixed locations as central organizing elements, Poskett structures the book through six key phrenological artifacts (skulls, casts, books, letters, periodicals, and photographs), dedicating a full chapter to each. He then explores how objects in each category shaped the ways in which phrenology was communicated and practiced across a variety of contexts and global locations and how each object directed and redirected phrenology's wide range of meanings and political purposes.

This creative mode of organization has several productive effects. First, it frees the book from the constraining frameworks of linear time and narrowly defined locations, both of which would hobble a project aimed at understanding how networked global processes of material exchange transformed and reformed phrenology across the globe. Second, the use of objects as organizational nexuses allows the author to sharply foreground material culture as the crosscutting, multidirectional driver of forms knowledge and political engagement, situating phrenology (and, by extension, science itself) as a politicized and racialized dynamic global process. Third, the use of phrenological objects allows Poskett to circulate the specific variables of time and place (such as, culture) back into the frame of his history but on his own global terms. Materials of the Mind deploys material cultures of phrenology in the context of global projects (such as abolition, colonialism, and nation building) that are at once grounded in specific locations yet also fundamentally connected to global flows of politics and power.

As its subtitle indicates, this work is particularly attuned to issues of race. Phrenology was an explicitly “racial science,” fundamentally concerned with indexing types of humans and deeply embedded in associated projects like empire and (anti)colonialism. It is easy work to demonstrate that phrenology was racist, but while the book makes many of those racist arguments clear Poskett's engagement with race is also more sophisticated. He examines how phrenological frameworks for thinking about hierarchies of human type were deployed in very different ways, depending on the agent and the context. Phrenological projects could—and did—argue that white Europeans were superior. But phrenology was also taken up in ways that were (for example) intended to advance arguments about emancipation or to stabilize national identity in the face of imperial domination.

Readers will find that every chapter of this book is distinguished by impressive archival work across many collections in numerous global locations and languages. Detail, references, and illustrations abound, supporting Poskett's fundamental commitment to exploring material culture's role in shaping a global history of science. Rather than following any analytical template, the individual chapters offer multiple approaches to “following” objects. This variety is nicely illustrated by the juxtaposed chapters “Skulls” and “Casts.” “Skulls” follows the collecting of skulls by British citizens in three disparate places—Hawaii, Egypt, and the Arctic—noting the different ways British travelers collected skulls in various cultural contexts they understood little or nothing about even as the skulls they collected bore distinctly different, unseen meanings. The building of British skull collections stands in contrast to the chapter “Casts,” which is structured inversely from “Skulls” and focuses largely on the personal and phrenological fortunes of one individual man, Eustache Belin. Born a slave in the French colony of Saint-Domingue in the later eighteenth century, Belin lived through colonial violence and uprisings in Haiti and arrived in France in 1812. The cast made of his head becomes a sort of phrenological ground zero for conflicting, intersecting intellectual and political arguments about race and empire, demonstrating how one individual head can be reread in different contexts for dissimilar reasons and with very diverse results. Rather than many skulls converging in British collections, one replicated head circulates across the globe, taking on opposing narratives, scientific interpretations, and social purposes as it moves.

While phrenology's varied materials, diverse transnational fortunes, and divergent purposes give shape to this excellent work, Materials of the Mind also makes a substantial contribution the scholarly conversations around global historiography and what it means to write a global history of science. Poskett tracks how objects associated with phrenology morph and shift as different people in different (yet often linked) places embrace them in the service of different racialized and political projects. As he does so, he makes a compelling case for how the history of science might be understood as part of the developing field of global studies. As both an exploration of phrenology specifically and as a scholarly work interested in advancing the question of what it means to write a global history of science, Materials of the Mind comes out ahead.