After the rules of Christian dialectic and the review of the errors of ancient heresies comes at last the book “Concerning the Orthodox Faith.” In this book, John of Damascus retains the same order as was adopted by Theodoret 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 page, and thus 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 œcumenical synods or accepted by the approved leaders of the Church.