John of Damascus on Islam. The "Heresy of the Ishmaelites." By Daniel J. Sahas. Sahas, Daniel J. John, of Damascus, Saint. Christianity and other religions Islam. Islam Relations Christianity. BP172 .S22 297.09 SAJ Based on the author's thesis, Hartford Seminary Foundation. Bibliography: p. [160]-168. Leiden: Brill, 1972. 1972. 1972 Text xvi, 171 p.; eng