What did St. Paul mean when he wrote "discerning the body"? The Greek text for 1 Cor. 11:29 has a variant (followed by the King James Version as well as the Douay-Rheims) which qualifies "the body" with the phrase "of the Lord".
There are three ways I see of interpreting this, all of which seem orthodox (that is, proper to Catholic faith) to me. These three ways supplement one another, building upon one another, to the point that each must be considered as necessary to a proper "discerning [of] the body [of the Lord]".
- Acknowledging the Real Presence of the Body (and Blood) of the Lord under the appearances of the bread and wine
- Recognizing that the "body of Christ" is simultaneously (although in different ways) the Eucharist and the Church, of which we are members
- Being mindful of those other members of the body of Christ
Augustine, The Correction of the Donatists 11, 50:
But those with whom we are arguing, or about whom we are arguing, are not to be despaired of, for they are yet in the body [I think he means by this that they are still alive]; but they cannot seek the Holy Spirit, except in the body of Christ, of which they possess the outward sign outside the Church, but they do not possess the actual reality itself within the Church of which that is the outward sign, and therefore they eat and drink damnation to themselves. (1 Cor. 11:29)Augustine is pointing out that there are heretical divisions which have the "outward sign" — i.e., a communal meal whose elements are bread and wine — but do not possess the actual reality (the "substance") under that outward appearance. This seems to me to refer to a celebration of the Lord's Supper which is simply (and only) bread and wine, rather than the actual Body and Blood of the Lord under the appearances of bread and wine. In consuming a "mock" Eucharist (as a result of being outside the Church and thus deprived of its sacramental efficacy), they are eating and drinking judgment.
Augustine, Sermon 82, 1:
As we heard when the Holy Gospel (John 6:55ff) was being read, the Lord Jesus Christ exhorted us by the promise of eternal life to eat His Flesh and drink His Blood. Ye that heard these words, have not all as yet understood them. For those of you who have been baptized and the faithful do know what He meant. But those among you who are yet called Catechumens, or Hearers, could be hearers, when it was being read, could they be understanders too? Accordingly our discourse is directed to both. Let them who already eat the Flesh of the Lord and drink His Blood, think What it is they eat and drink, lest, as the Apostle says, “They eat and drink judgment to themselves.”Again, Augustine makes it clear that those who receive Holy Communion must "think What it is they eat and drink": they must "discern" that the Eucharist is the Flesh and Blood of Jesus Christ, welling up to eternal life, as the Lord himself promised. Failure to accept this results in judgment.
Augustine, Sermon 52, 4:
He gave to the disciples the Supper consecrated by His Own Hands; but we did not sit down at that Feast, and yet we daily eat this same Supper by faith. And do not think it strange that in that supper which He gave with His Own Hand, one was present without faith: the faith that appeared, afterwards was more than a compensation for that faithlessness then. Paul was not there who believed, Judas was there who betrayed. How many now too in this same Supper, though they saw not then that table, nor beheld with their eyes, nor tasted with their mouths, the bread which the Lord took in His Hands, yet because it is the same as is now prepared, how many now also in this same Supper, “eat and drink judgment to themselves”?Augustine links the celebration of the Eucharist and the reception of Holy Communion with "that supper which [Christ] gave with His Own Hand"; he calls each celebration of the Eucharist "this same Supper". Furthermore, those who receive the Eucharist "without faith" are placing judgment upon themselves. What "faith" is that? As Judas betrayed Christ, so too we betray him in a way when we deny his Real Presence in the sacrificial banquet of the Eucharist.
John Chrysostom, Homily 2 on 1 John, 1:
The disciples, then, knew Him not, save “in the breaking of bread.” And truly he that eateth and drinketh not judgment to himself in the breaking of bread doth know Christ.Chrysostom says that one who "knows Christ" as did those disciples ("in the breaking of the bread") does not bring judgment upon himself when he receives Communion. This seems to me again to refer to belief in the Real Presence of Christ in the sacrament.