This article applies aspects of Niklas Luhmann's theory of society to 19th century Quebec ultramontanism. Luhmann analyzes the difference between pre-modern and modern societies in terms of a shift from a dominance of stratified differentiation to a dominance of functional differentiation. It is shown that the Quebec ultramontane view of society is consistent with the former but not the latter. Accordingly, the ultramontane idea that French Canadian society has an overall mission reflects an organizational and unified conception of society that seeks to subordinate all other functional selection criteria to those proper to the family and religion. This attitude is analyzed in Luhmannian terms as the preservation of French Canadians as an implicit stratum. Correspondingly, increasing dominance of functional differentiation is interpreted by the Quebec ultramontanes as a feature of the English-speaking societies around them. Preserving stratified features and combating functional differentiation is therefore seen as tantamount to preventing assimilation by these societies. The superimposition of pre-modern/modern in Luhmannian terms on French/English is seen as the key to understanding the mission of Quebec ultramontanism. The application of a highly abstract and conceptually difficult theory of society and modernization to concrete phenomena presents certain obvious challenges. Not the least of these is the specification of the general terms of the theory so that they can be tested in the light of concrete social events, and so that they can in turn shed new light on the events themselves. Niklas Luhmann's theory of society is particularly implicated with this consideration since his formulations are deliberately placed at a very high level of abstraction in order to extend their relevance to all societal phenomena. One way of responding to this problem, and the one undertaken here, is to apply the new conceptual tools to matters that have been thoroughly studied before with the express purpose of answering old questions in new ways and deepening the understanding of previous answers. In the background of this motive, of course, is the question of how Luhmann's theory goes beyond the achievements of his predecessors, most particularly, in the North American context, those of Talcott Parsons. In the present article, the relative freedom Luhmann gains by abandoning Parsons' fundamental four-function paradigm for conceiving functional differentiation and Luhmann's incorporation of different forms of differentiation, most particularly stratified differentiation, into the analysis of modernization, should be seen as addressing this question.1 In what follows, I first present aspects of Niklas Luhmann's theory of society and modernization, aspects which are then applied to a concrete, in this case historical problem: the development in the Canadian province of Quebec during the nineteenth century of an explicitly religious nationalism, usually known as French Canadian ultramontan