This hypothesis has been advocated brilliantly by Heitmüller and Bousset.[183] But what evidence can be adduced in favor of it? How may the Christianity of Damascus and Antioch, which is supposed to have been influenced by pagan religion, be reconstructed? Even Heitmüller and Bousset admit that the reconstruction is very difficult. The only unquestioned source of information about the pre-Pauline Christianity which is the subject of investigation is to be found in the Pauline Epistles themselves. But if the material is found in the Pauline Epistles, how can the historian be sure that it is not the product of Paul's own thinking? How can the specifically Pauline element in the Epistles be separated from the element which is supposed to have been derived from pre-Pauline Hellenistic Christianity? [183] See especially Heitmüller, "Zum Problem Paulus und Jesus," in _Zeitschrift für die neutestamentliche Wissenschaft_, xiii, 1912, pp. 320-337; "Jesus und Paulus," in _Zeitschrift für Theologie und Kirche_, xxv, 1915, pp. 156-179; Bousset, _Jesus der Herr_, 1916, pp. 30-37. The process of separation, it must be admitted, is difficult. But, according to Bousset and Heitmüller, it is not impossible. There are passages in the Epistles where Paul evidently assumes that certain things are known already to his readers. In churches where Paul himself had not already had the opportunity of teaching, notably at Rome, those elements assumed as already known must have been derived, it is said, from teachers other than Paul; they must have formed part of the pre-Pauline fund of Hellenistic Christianity.