From an advice column in the U. S. Catholic:
Should you pass on communion at a Lutheran church or participate fully?
You are at the wedding of a beloved family member or friend, which is taking place at a Lutheran church. You gladly accepted the invitation to celebrate this happy day with the bride and groom. But then there is a call to come to the table of the Lord’s Supper, to receive communion. This is the awkward moment you knew was coming. Can you, and should you, a practicing Catholic, accept the invitation?
According to the Code of Canon Law, receiving communion in a Protestant church is generally not permissible. According to canon 844, “Catholic ministers may licitly administer the sacraments to Catholic members of the Christian faithful only and, likewise, the latter may licitly receive the sacraments only from Catholic ministers.” The key term here is licit. If a Catholic receives communion from a Protestant minister, it is generally considered “illicit” or unlawful.
The reason for the Catholic Church’s general rule against sharing in the Eucharist with other churches is that a person can only be in full communion with one church. As a Catholic, the core of one’s union with Christ is union with the church. The center of this union lies in the reception of the sacrament of the Eucharist during Mass, which is both a confession and embodiment of unity with the Roman Catholic Church.
But canon 844 includes an exception to the rule “whenever necessity requires or general spiritual advantage suggests, and provided that the danger of error or indifferentism is avoided.”
The Second Vatican Council’s Decree on Ecumenism said that, as a general rule, common worship and eucharistic and other sacramental sharing should “signify the unity of the church.” But it acknowledges that such sharing can also be seen as advancing unity. In fact, according to the decree, “the gaining of a needed grace sometimes commends” it.
Still, within the confines of canon law, the exceptions to the rule are rather limited, and receiving communion from a Lutheran pastor during a wedding would normally be seen as “illicit” for Catholic wedding guests. At the same time, some Catholics would like to, and do, receive communion on these rare occasions.
These Catholics, after a careful examination of their conscience, find compelling reasons to “gain a needed grace” by receiving communion in a Protestant church. And it is also true that eucharistic sharing has occurred at the highest levels of the church. Even Jesus occasionally broke the religious law of his day, though he did so to fulfill the “spirit” of the law.So it is possible that one could follow Jesus’ lead. In our example a compelling reason might be to demonstrate one’s deep love and commitment to nurturing the relationship of the newly married couple. Intercommunion could be a “yes” to God by witnessing to God’s presence in the marriage and committing to God’s work of salvation in their lives.
In the end, this may be fulfilling the “spirit” of canon law while going against the letter.
That last bit is casuistry of the highest order! Breaking a canon law in order to fulfill it? What’s surprising to me is that it’s taken for granted that a Lutheran pastor would be glad to commune a Roman Catholic visitor. See too the first comment in the consequent thread that quotes the rest of the canon law cited here, that the communion can only be in a church with “valid” sacraments, which would be the Eastern Orthodox and some of the separated Catholic off-shoots. Not Protestants, including Lutherans and Anglicans, who are not thought to truly have the Eucharist. This interpretation, though, makes liberal-Protestant-style ecumenism trump everything.
At any rate, is this argument for closed communion–actually, the rejection of altar fellowship–the same as what confessional Lutherans make, or is there a difference? Note, for example, that the nature of the sacrament is not even brought up in this reasoning.