Source: www.ccel.org
Prologue (from Migne, PG.
After the rules of Christian dialectic and the review of the errors of ancient heresies comes the at last the book "Concerning the Orthodox Faith." In this book John of Damascus retains the same order as was adopted by Theodore in his "Epitome of Divine Dogmas," but takes a different method. For the former, by the sheer weight of his own genius, framed various kinds of arguments against heretics, adducing the testimony of the sacred text, and so he composed a concise treatise of Theology. Our author, however did not confine himself to Scripture, but gathered together also the opinions of the holy Fathers, and produced a work marked with equal perspicuity and brevity, and forming an unexhausted storehouse of tradition in which nothing is to be found that has not been either sanctioned by the ecumenical synods or accepted by the approved leaders of the Church.
He followed chiefly Gregory of Nazianzus, who, from the great accuracy of his erudition in divine matters, earned the title "The Theologian," and who left scarcely any Section of Christian learning untouched in his surviving works, and is free from any taint or suspicion of the slightest error. John had read his books so assiduously that he seemed to hold them all in the embrace of his faithful memory. Therefore throughout this work you may hear not so much John of Damascus as Gregory the Theologian expounding the mysteries of the orthodox faith. John further made use of Basil the Great, of Gregory of Nyssa, and especially of Nemsius, bishop of Emesa in Syria, whom he love most of all; likewise of Cyril of Alexandria, Leo the Great, Leontius of Byzantium, the martyr Maximus: also of Athanasius, Chrysostom, Epiphanius, and, amongst others, that writer who took the name of Dionysius the Areopagite. Out of all these he culled on every hand the flower of their opinions, and concocted most sweet honey of sound doctrine. For his aim was, not to strike out views of his own or anything novel, but rather to collect into one single theological work the opinions of the ancients which were scattered through the various volumes.
