Historians have never been more unanimous regarding the ambiguity of national identity in central Europe. Recent studies by Pieter Judson, Jeremy King, Alison Fleig Frank, Tara Zahra, and Christopher Fischer, to name only a few, have illustrated the complexity, contingency, indeed mutability of ethnic, linguistic, and confessional loyalties in the vast swathe of land between the Rhine and the Vistula. Until now, however, no work in English has explored the same set of issues in the German-Danish border regions of North Schleswig. In his crisply written new monograph, Peter Thaler fills this gap in the historiography admirably.

The author begins with a wide-ranging review of the literature. The best work on nationalism, Thaler argues, recognizes both the essentialist (Gellner, Brubaker) and instrumentalist (Anderson, Hobsbawm) elements of national identity formation. Thaler suggests in turn that German, Danish, and Frisian loyalties to ethnicity, confession, and language (matter) were circumscribed by a pragmatic volunteerism (mind) that incorporated political, cultural, and economic realities. To provide the background for evaluating these tensions between mind and matter, chapters two and three survey the political, linguistic, and cultural history of Schleswig from the early Middle Ages to the present. Tackling these themes over the longue durée pushes the author to move rather briskly at times, but these chapters are probably necessary in setting the stage for subsequent analysis.

Chapter four is the centerpiece of the book, tracing the “dualistic” nature of national identity in North Schleswig from the middle of the nineteenth century to the present day. After Schleswig was ceded to Prussia in 1864—and then incorporated into the new German Reich in 1871—rural Danish-speakers became politicized, largely in response to Prussian Germanization policies. Yet continuing urbanization and subsequent emigration to Denmark weakened the Danish national movement, while a gradual improvement in Danish-German relations facilitated greater Danish identification with Germany. Not surprisingly, the percentage of Danish voters plunged from nearly a quarter (twenty-three percent) of the entire Schleswig-Holstein electorate in 1871 to barely five percent in 1912.

A series of plebiscites outlined in the 1919 Versailles Treaty changed the ethno-territorial status quo significantly, however, ceding much of North Schleswig to Denmark. To be sure, it was now the German minority that clamored for closer linguistic and cultural ties to its former homeland. Nevertheless, the subjectivity of national identity in interwar North Schleswig is exemplified by the fact that many Danish-speaking North Schleswigers maintained a regional loyalty to German Schleswig-Holstein, for pragmatic economic as well as cultural reasons. The same “subjective” factors explain why many German-speaking Schleswigers sought inclusion in the Danish minority community after World War II, even when they had little interest in learning the Danish language. Chapter five supplements these general assessments through biographical studies of the Vormärz politicians, Nicholas Falck and Christian Paulsen; the interwar regionalist Cornelius Petersen; and a series of postwar interviews.

Chapter six expands the book's scope to compare the North Schleswig experience with equally “transitional” or “shifting” identities in Polish-German and Prusso-Lithuanian border regions. The strength of this chapter is Thaler's emphasis on religion alongside ethnicity, class, and language, an independent variable that could hardly be evaluated in almost exclusively Protestant North Schleswig. Chapter seven concludes by reiterating the diverse, subjective, indeed volunteeristic nature of national identity formation in North Schleswig and elsewhere.

Convincing in most respects, the unique nature of the North Schleswig case does raise questions of comparability. As Thaler notes in the introduction, “This analysis focuses especially on national self-identification, because it was self-identification rather than palpable differences in color, creed, or lifestyle that guided the nationalization process.” But “palpable differences in color, creed, or lifestyle” were essential components of the nationalization process in many other parts of Europe. For Jews, Muslims, and Gypsies, not to mention Serbs, Poles, or Albanians, it was never quite as easy to make the kind of conscious mental “transitions” that Thaler documents in North Schleswig. At the same time, the author may underestimate the important role played by racialist (völkisch) ideology in regional political culture from the 1890s to the 1940s. Some of the most vociferous German defenders of Danish self-determination before 1919, such as Johannes Schmidt-Wodder and Johannes Tiedje, cited Danish racial superiority vis-à-vis the “half-Slavicized” Prussians as reason for German Schleswigers to embrace their Nordic brethren. The Weimar liberal Cornelius Petersen could shift back and forth between German and Danish regionalism, bourgeois liberalism and Nazism, precisely because he saw little contradiction between regional Nordic democracy and Adolf Hitler's racist populism. Thus, at least during the first half of the twentieth century, a putatively “objective” (material) conception of Nordic racial affinities may have facilitated seemingly “subjective” (mental) transitions in cultural and linguistic identification.

Notwithstanding these minor qualifications, Of Mind and Matter remains a stimulating and well-researched study of national identity formation in an under-examined region. It deserves a wide readership from students of German and European history alike.