Scott Ables - Did John of Damascus Modify His Sources in the DeFide Orthodoxa?

In this short communication, I examine four passages in the De fide orthodoxa in which John of Damascus may have modified his sources.  B. Kotter indicates John is dependent in these passages on Gregory of Nanzianzus, Pseudo-Dionysius, Maximus the Confessor, Leontius of Byzantium and Pseudo-Cyril.  In these passages John repurposes the Christological term perichoresis, inserting it into his source material for his Trinitarian argument. Accepting Vassa Kontouma-Conticello’s analysis that Pseudo-Cyril is not a source of John, these passages comprise the genesis of Trinitarian perichoresis.  In light of this significant advancement in Trinitarian terminology, is John true to his claim that he will say nothing of his own?  Consequently, I examine the dependencies indicated by Kotter to ascertain the extent of John’s dependence and modification of these sources by asking two questions: 1) To what extent is John dependent on the sources Kotter indicates? And, 2) To what extent is John modifying these sources?  Answering these questions, should shed some light on what John means by saying he would say nothing of his own, and to set the stage to ask what is his purpose in introducing Trinitarian perichoresis.  However, any conclusions must be provisional as my analysis is confined to the external authorities noted by Kotter and excluding Kotter’s references to other works of John, consequently, development in John’s thought and indirect dependence on external authorities in those works is not investigated here.