score:2
Background: At the time in question, Western churchmen taught that Christ must be recognized as having "two natures" (divine and human) which were harmoniously combined in one person, following the formula of the Council of Chalcedon. Some Eastern churchmen (the 'East' includes North Africa here) tended toward the view that Christ's divine and human qualities constituted "one nature." This doctrine was known as Miaphysitism. It tried to avoid falling into the heresy of Monophysitism, (teaching that Christ had a single nature which was divine) but left room for those who wanted to affirm Christ's humanity and divinity in one nature. The key phrase in the Chalcedonian creed was the Christ was:
to be acknowledged in two natures, inconfusedly, unchangeably, indivisibly, inseparably; the distinction of natures being by no means taken away by the union.
Because Miaphysitism did not acknowledge the "two natures" of Christ endorsed at Chalcedon, the Western churchmen, as well as many in the East, viewed it as heresy.
Emperor Zeno attempted to bring unity to the Church by issuing the Henotikon, which condemned both sides of the Miaphysite controversy and pleased neither of them. By avoiding the term "nature(s)," the document glossed over the primary issue, since the main parties agreed that Christ was clearly one person and one being, not two. Although neither side was satisfied, the document was more adamantly opposed in the West, which saw it an attempt to provide a way for semi-Monophysites to be accepted as orthodox. The West also resisted what it saw as the Emperor's attempt to assert his theological authority over that of the Pope and an Ecumenical Council.
Pope Felix III's first act as pope was to condemn the Henotikon. As the controversy continued to cause division, he eventually excommunicated Acacius for his role. The issue was not only that Acacius may have helped create the Henotikon but he clearly endorsed it and promoted those bishops who supported it, notably at Alexandria. After Patriarch John Talaia, was exiled from that city, he arrived in Rome and reported the attitude of the Eastern churches to Felix, who summoned Acacius to Rome to explain his conduct. When papal legates brought the summons to Constantinople they were imprisoned and required to receive Communion from Acacius. When this was reported to Felix, he held a synod in 484 in which he denounced his own legates and excommunicated Acacius.
The main theological issue at stake here was thus Chalcedonian orthodoxy versus Miaphysitism. The secondary issue was Caesaropapism, the idea that the Emperor had a major role, even superior to the pope, in determining theological policy.
Note: the exact role of Acacius in the creation of the Henotikon is debated. Western sources tend to consider him instrumental in its drafting while Eastern sources tend to view him as entirely orthodox in his personal view, accepting the Henotikon only by the forceful influence of the Emperor.