St. Thomas Aquinas on avoiding cooperation in sin with heretics and schismatics (communicatio in sacris)

 

St. Thomas Aquinas teaches below in his Summa Theol. II, Q. 82, Art. 7, 9, Pt. III: “The Minister of the Holy Eucharist”:

“I answer that, as was said above (aa 5, 7), heretical, schismatical, excommunicate, or even sinful priests, although they have the power to consecrate the Eucharist, yet they do not make proper use of it; on the contrary they sin by using it. But whoever communicates with another who is in sins, becomes a sharer in his sin. Hence we read in John's Second Canonical Epistle (11) that 'He that saith unto him, God speed you, communicateth with his wicked works.' Consequently it is not lawful to receive Communion from them, or to assist at their mass.” (Article 9)… “And therefore whoever hears their mass or receives the sacraments from them, commits sin… By refusing to hear the masses of such priests, or to receive Communion from them, we are not shunning God's sacraments; on the contrary, by so doing we are giving them honor: but what we shun is the sin of unworthy ministers” (reply to objection 1). Furthermore St. Thomas states in reference to heretical, schismatic and excommunicated priests, “Such persons as are separated from the Church by heresy, schism, or excommunication, can indeed consecrate the Eucharist..; but they act wrongly, and sin by doing so; and in consequence they do not receive the fruit of the sacrifice, which is a spiritual sacrifice” (Article 7). And further, “But because he is severed from the unity of the Church, HIS PRAYERS HAVE NO EFFICACY” (reply to objection 3 of article 7).

This, ultimately, is the charter for those who keep the faith at home, in order to honor the Sacraments and avoid cooperation in sin.

(Taken from Necessary intention in Traditionalist Orders lacking, by Teresa Stanfill Benns, 2022)