Ernst Troeltsch’s formulation of three sociological types (church, sect, and mysticism) developed in The Social Teaching of the Christian Churches has been widely influential in ongoing thinking about the church. While, for Troeltsch, each of these types can be traced back to various impulses within primitive Christianity, history shows that the Christian community’s interaction with the social, political, economic, and cultural contexts in which it found itself led it to develop into one of these predominant forms, thereby lending to the relative strength and success of the Christian movement in that situation. Troeltsch believed, however, that the modern emphasis on individual freedom and the corresponding loss of social unity and cohesion posed enormous challenges for nurturing and sustaining Christian social ideals in any one of these three types. While the church type is superior to the other two because it can sustain community in the context of fragmentation, it relies on an understanding of authority and the use of compulsion that is out of step with the modern spirit. Troeltsch’s inclusion here signals the importance that sociology would come to play in twentieth century ecclesiology.