In fairness, this non una cuм issue was discussed prior to Vatican II.
Fr. A. Fortescue, The Formula of Hormisdas, CTS 102 (London: Catho-
lic Truth Society 1913), 12.
“The purpose and chief use of the diptychs (Canon) was to retain Catholic communion both of the living with one another and of the living with the dead.”
“To read the name of a living bishop in the diptychs was always a recognized sign of communion with him.”
R. Maere, “Diptych,” Catholic Encyclopedia (New York: 1913) 5:23.
“The liturgical diptychs admitted only the names of persons in communion with the Church; the names of heretics and of excommunicated members were never inserted.”
(Verdale WA: Catholic
Research Institute 2002), 8–9.
“The main object of the Rule of Faith of Pope St. Hormisdas was to condemn the naming of heretics in the diptychs,… reportedly 2,500 bishops signed the Rule of Faith in order to become restored to
communion with the Church. Until they signed they were denied communion solely and specifically because they had persisted in naming heretics in their diptychs.”
1756 Bull of Pope Benedict XIV:
“…’Therefore where commemorations are customarily made in the sacred liturgy, the Roman Pontiff should be first commemorated, then one’s own Bishop and Patriarch, provided they are Catholic. But if either of both of them are schismatics or heretics they should by no means be commemorated’.”
The theologian de la Taille:
“Hence were anyone to mention by name an infidel, a heretic, a schismatic, or an excommunicated person (whether a king, or a bishop, or any other) either in the prayer Te igitur or in our commemoratio
pro vivis, he would certainly violate the law of the
Church.”
1729 the Vatican Congrega-
tion for the Propagation of the Faith decreed:
… "There is hardly any rite among the heterodox that is not stained with some error in faith… especially where a commemoration is made of living
Patriarchs and Bishops — schismatics and heretics— who are proclaimed preachers of the Catholic faith. For this reason, any Catholics who come together under circuмstances like this to celebrate a
rite of prayer and worship cannot excuse themselves from the sin of evil common worship, or at least, from the sin of pernicious scandal"