The question whether there were two wills (Dyothelitism) or one will (Monothelitism) in the Word made flesh was inevitable. The Chalcedon* settlement had insisted on the doctrine of the two natures in the incarnate Son. But some of the followers of Cyril* of Alexandria, believing that any suggestion of a duality must lead straight back to Nestorianism* were dissatisfied. These opponents of Chalcedon became known as Monophysites. Holding that the term “nature” and “person” are synonymous, they sought to secure the Cyrillian formula, “one nature in the Word made flesh.” Cyril had accepted the Chalcedon terms, but in his endeavor to overcome any idea of a Nestorian juxtaposition of natures, had allowed himself to use the phrase “one nature.” His Monophysite followers were less concerned to maintain the two-natures doctrine. Under the influence of [[Leontius of Byzantium]]* (sixth century), however, an interpretation of Chalcedon in a Cyrillian sense was effected. But dissatisfaction with the settlement continued and found expression in a renewed conflict over whether there were two wills or one possessed by the “two-natured” Christ.
Clearly the ethical complement of Monophysitism* is Monothelitism. Thus to allow one will would be to sanction Monothelitism. In order to clear up the issue-which, like the preceding controversy over Dyophysitism and Monophysitism, nearly tore the empire asunder-the emperor Heraclius instructed Sergius* (d.638), patriarch of Constantinople, to find a formula of mediation, which would pacify the Monophysites. Sergius thereupon advanced the thesis that the Word-made-flesh did all things through the action of a single divine-human energy.
The formula was however, opposed by Sophronius,* later to become patriarch of Jerusalem, and this compelled Sergius to restate his position. He then set aside the idea of “energy” and affirmed the existence of one will in the divine-human Christ. But to the upholders of the Chalcedon doctrine, two natures implied two centers of volition. A heated controversy over the issue followed until the Council of Constantinople* (681), the sixth ecumenical council of the church, ruled out-though probably wrongly-Monothelitism, and settled for Dyothelitism-for two wills-as being more in harmony with that of two uncompounded natures in Christ for which Chalcedon had declared.