In 1921, Marianne Weber published one of the greatest works of her late husband, Max, a book destined to become one of the foundations of modern social theory. Economy and Society was of such a scope and breadth that it touched on almost all aspects of social, economic, and political thought and, inevitably, a section was devoted to the nation. According to Weber, the latter could never be defined unambiguously, in terms of the qualities and traits shared by those who saw themselves as its members. The nation, he argued, meant “above all, that it is proper to expect from certain groups a specific sentiment of solidarity in the face of other groups.” Thus, “the concept belongs in the sphere of values” and there “is no agreement on how these groups should be delimited or about what concerted action should result from such a solidarity.”