From NT times the church has relied on the decisions of councils called by recognized authority to settle disputes over doctrine and discipline. When a council involves representative bishops from the whole church, it is called "general." When the decisions of a council are recognized by the whole church, it is called "ecumenical" (from the Greek oikoumen', "inhabited world"). The terms "general" and "ecumenical" are not quite synonymous. Seven councils are recognized as ecumenical by both eastern and western churches: Nicaea (325), which dealt centrally with the divinity of the Logos; Constantinople (381), which established the formula for expressing the Trinity and dealt with the divinity of the Holy Spirit; Ephesus (431), which decided against Nestorianism and promulgated a definition of the person of Christ; Constantinople II (553); Constantinople III (680-681); and Nicaea II (787). The latter three councils did refining work on the person of Christ and defined the role of images in worship.
Because of their crucial role in defining the doctrine of the Trinity and Incarnation, Anglicans often regard the first four councils as the most important. See Chalcedonian Definition; see Monothelitism.