This chapter, the first in the book’s second part, analyses Albrecht Ritschl’s understanding of theology as Wissenschaft. Ritschl’s complex relationship with his sometime teacher, F. C. Baur is then explored through a full analysis of his polemical exchange with E. Zeller over the use of ‘historical method’ in theology. A final section of the chapter offers a full analysis of Ritschl’s exegetical work and his theory of Primitive Christianity, the relevance of which for his theology has rarely been observed. On the basis of a close study of Ritschl’s account of the Early Catholic Church (1857) it is shown how Ritschl, step by step, transforms the Tübingen consensus about the origins of Christianity. This transformation is couched in historical analysis, but it also and at the same time sets up an idea of early church history conducive to Ritschl’s own theology.