One intriguing question in the history of heresiology is how in the face of imperial pressure the Lateran Synod of 649 came up with substantially the same solution to the Monothelite crisis as would the Sixth Ecumenical Council of 680-1. How did the decisions of a western council anticipate so closely the doctrines of a universal council agreed to thirty years later by both eastern and western Churches?
Certainly, the influence of Maximus the Confessor was preponderant at the earlier synod. For some years previous he had led the fight against both Monenergism and Monothelitism as corruptive of Christological orthodoxy. He was present at the Lateran Synod, and though not a bishop he exerted a heavy influence over Pope Martin I and the assembled bishops.
But there may be another layer in this line of dependency. Were the western bishops so theologically unsophisticated that they could be convinced by a single eastern monk, generally unconversant in Latin, to oppose a determined emperor in Constantinople on the abstruse question of the wills in Christ?
The great standard of orthodoxy in the west was St. Augustine of Hippo. It is logical to presume that whatever the level of their theological sophistication, the western bishops would be familiar with Augustine’s Christological teaching. When we look at the master’s writings on the subject of Christology, in fact, we find clear and unambiguous language about the two wills in Christ, human and divine. In treating of the Agony in the Garden in his Commentary on Psalm 93, especially, does he see the dynamic of their functioning in tandem. At Lateran 649, the western bishops could recognize Augustine’s dyothelite Christology in the theology of Maximus and could confess it boldly.