A general introduction to the various contexts or stages in the development of Bernard Lonergan's thought. Specifically, it is an hermeneutical investigation of his notion of conversion as foundational for contemporary theological method. The author focuses on Lonergan's major works, Grace and Freedom, Verbum, Insight, and Method in Theology, and reconstructs the several successive contexts for each of these works. Contents: The Early PeriodóThomism and the Systematic Exigence; The Middle PeriodóThe Problem of Integration and the Critical Exigence; The Later PeriodóTheology and the Methodical Exigence; ConversionóSummary and Criticisms.