Augustine’s letter ep. 184A, transmitted only in one manuscript, is an important witness to the complexe situation of Augustine in 417/418. The paper aims to show how Augustine uses anti-Pelagian and anti-pagan strategies in order to convince the (otherwise unknown) addressees of his own theology. For the anti-Pelagian topics a set of standard arguments is introduced that was developed in the years 416/417 in the Anti-Pelagian controversy and can be compared with sermons and other letters. Against the pagans, the letter refers to the first eleven books of De civitate dei. The paper will raise the question how these two fields fit each other. In preparation of a philological and historical commentary the methodological problems of such a commentary will be discussed.