Today in the Decree on the Catholic Churches of the Eastern Rite, we read through the second chapter on “Preservation of the Spiritual Heritage of the Eastern Churches.”
In article 5, the Council Fathers affirm the great richness of the Eastern heritage and claims it as part of the heritage of the whole Church. They aslo acknowledge the right of the Eastern rites to rule themselves.
Article 6 speaks of the great liturgical traditions and how they are to be preserved and kept unchanged except for cases of “organic improvement.”
Here are the footnotes:
(5) Cfr. Leo XIII, Litt. Ap. Orientalium dignitas, 30 nov. 1894; Ep. Ap. Praeclara gratulationis, 20 iun. 1894, et documenta in nota 2 allata.
(6) Cfr. Benedictus XV, Motu proprio Orientis catholici, 15 oct. 1917, Pius XI, Litt. Enc. Rerum orientalium, 8 sept. 1928, etc.
(7) Praxis Ecclesiae catholicae temporibus Pii XI, Pii XII, Ioannis XXIII motum hunc abunde demonstrat.