Steinar Stjernø's important and fascinating book will be valuable to political theorists and sociologists interested in the idea of solidarity from the nineteenth century through the present, to political historians concerned about the uses of solidarity in the political discourses of left-wing, religious, and fascist parties and movements, and to historians of political thought and of ideas who address methodological questions in their field.

As his subtitle indicates, Stjernø writes the history of an idea. He draws his methodological inspirations from German conceptual history in the hermeneutic tradition and the “Cambridge School” of Quentin Skinner and John Pocock, who study political languages as dynamic structures that are modified and changed. Stjernø studies the specific discourses of solidarity, within their social and political contexts, looking for the conceptual changes in the use and meaning of solidarity. Whereas Skinner and Pocock emphasize individual speakers, the full political context, and concurrent changes in other concepts, Stjernø begins and ends with a few individual theorists (such as Auguste Comte and Karl Marx, Jürgen Habermas and Hans Kung), and his empirical work focuses on the language of political movements and parties, especially their political programs, in order to make possible the study of an extensive span of time and many countries.

To understand differences in solidarity discourses and look for changes, Stjernø analytically distinguishes four aspects of solidarity. What is the “foundation” of solidarity; that is, to what extent and in what ways does the self identify with others? What is the objective or goal of solidarity? How inclusive of others is it? And what is its “collective orientation” or (conversely) how much autonomy does it leave to individuals? As the author points out, these questions are all aspects of the empirical and normative questions of the relation of “I” to “we” and of “we” to “they.” He analyzes individual theorists' ideas and parties' programs in terms of these four aspects—and produces about 25 four-columned tables that display theorists' and programs' ideas on solidarity in a clear, easily comprehensible, shorthand form that his text both explains and elucidates.

Stjernø follows his introductory methodological chapter with three chapters in which he analyzes three “traditions” of solidarity. One is the classical social theories of nineteenth-century sociology, such as Charles Fourier, Auguste Comte, and Émile Durkheim, who, except for Max Weber, were concerned with trying to produce social harmony or order in the face of nascent capitalism without another revolutionary upheaval. A second tradition stems from Marx, who focused on class solidarity to realize the interests of the workers in a unified struggle—but who also, Stjernø notes, had an alternative vision of a future society free of capitalism where all could be free members. Later Marxists, like Eduard Bernstein and Lenin, took Marx's concepts of solidarity in differing directions. The third tradition is Catholic and Lutheran ethical teachings, that is, in papal encyclicals and the proclamations of the Lutheran World Federation. In both denominations, Stjernø finds that solidarity has not been used as a term nor stressed as an idea until after World War II, and then particularly in circumstances where the Christians could use it without the taint of Marxist, leftist, or revolutionary ideologies. In these chapters lies a rich, multifaceted presentation of differing meanings of solidarity in social theory, socialist theory, and religious ethics.

Stjernø then asks the more empirical question (p. 89): “How, when and why are these ideas of solidarity reflected in the institutional ideologies of social democratic and Christian democratic parties in Western Europe?” The next four chapters take us through the languages of solidarity, beginning with the First International and then the subsequent changes in social democratic parties, the Christian democratic discourse, and their convergences, or not, at the end of the last century and the beginning of this. A fifth chapter treats the historically significant but now eclipsed Marxist-Leninist and fascist solidarity. Of particular interest in these chapters is the author's nuanced treatment of solidarity in Scandinavian countries; his emphasis on the differing languages of socialist and social democratic solidarity in northern Europe, southern Europe, and Britain; and his use of changes in the language of solidarity as a way to trace the transformation of Communist Parties in southern Europe.

In his two final chapters Stjernø asks about the prospects for solidarity in the present day. First, he looks for coherent theoretical statements about solidarity from contemporary social theorists like the American communitarians, socialists like Anthony Giddens, and theologians like Jürgen Moltmann. Then, in an epologic final chapter, he analyzes the multiple threats to solidarity posed by contemporary challenges such as consumerism and globalization.

Because of the breadth of his coverage, any reader can quibble with parts of his work; but I think Stjernø's overall project will stand up well. So I would like to end this review with some questions. It is always difficult to set the boundaries of a concept and to distinguish the history of a concept from the history of a word. Stjernø explicitly excludes liberals and conservatives, even when they use concepts of solidarity (p. 10), and he excludes liberal and conservative ideas of community (except when he discusses American communalism among the contemporary statements of solidarity [pp. 10, 15, 295–98]) from his discussion of solidarity. Those exclusions are, I think, challenges for further studies that would, for instance, look at liberal and conservative discourses on the idea of community with attention to whether and how they converge with socialist and religious languages of solidarity. In his empirical chapters, he focuses on party programs and does not look at policies (p. 10); that connection, already examined by some scholars in specialized studies, could use further analysis. Similarly, he stresses the need to institutionalize solidarity in the modern world (p. 307) but leaves much work here for others to do. Finally, this study focusing on Western Europe should be followed by a similar analysis of the languages of solidarity (including religious languages) in North America, at both national and state or provincial levels. Solidarity in Europe, valuable in itself, can serve as a wise guide for future questions and research.