36 From the very first centuries of the Church bishops, as rulers of individual churches, were deeply moved by the communion of fraternal charity and zeal for the universal mission entrusted to the Apostles. And so they pooled their abilities and their wills for the common good and for the welfare of the individual churches. Thus came into being synods, provincial councils and plenary councils in which bishops established for various churches the way to be followed in teaching the truths of faith and ordering ecclesiastical discipline. This sacred ecumenical synod earnestly desires that the venerable institution of synods and councils flourish with fresh vigor. In such a way faith will be deepened and discipline preserved more fittingly and efficaciously in the various churches, as the needs of the times require.
Source: Christus Dominus (Vatican.va)