This thesis is a study of Johann Adam Moehler's critical theology as an achievement in the nineteenth century's quest for a historical methodology. As the first Catholic theologian to apply a critical-historical analysis to the development of doctrine, Moehler is important as both the theologian and as a German historian. As the theologian, Moehler's efforts to discover the essential meaning of Christian doctrine led him to conclude that doctrine develops within a human context of experience, namely, the Catholic Church. This development of doctrine is possible given the organic nature of the Christian community and its relationship to the divine. It is only the subjective form which doctrine assumes at different stages in life of the Church that is susceptible to change. The objective truth of Christian principles remains immutable. As the historian, Moehler applied a critical method, symbolism, to his theological subject matter. By an objective investigation of the symbols of Protestantism and Catholicism, he felt that the essential differences and the meanings of the respective confessions could be properly analyzed. History, as the proper framework in which to acquire the objective meaning of the Catholic experience, is the common denominator between Christ and his institution, the Church, and remains the only means of justifying its continued existence. This study of Moehler's ideas begins with a discussion of the historical context in which Moehler lived and by which he was influenced. This discussion highlights the German Aufklärung and its reaction to the French Enlightenment, the Romantic Movement as it uniquely developed in Germany and the rise of the Tübingen School as the locus of romantic Catholic theology in the early nineteenth century. The second chapter relates the details of Moehler's biography, particularly as a member of the Tübingen theological faculty. In the third chapter Moehler's critical theology is discussed as it reflects his historical consciousness and his methodology. The fourth chapter consists of a review of the literature written about Moehler as well as some interesting interpretations of his concepts and their consequences. Finally, the conclusion attempts to place Moehler in a perspective to his German philosophical heritage and to the historical theories of his time as a historical theologian.