RS 100 through 107 deals with “Communion under Both Kinds.”
In trying to make peace with clerical skittishness about offering the Cup, I’ve come to recognize that any number of local, cultural, and institutional factors are in play. The good news is that the act of taking up the Cup of Salvation still has meaning, otherwise the hierarchy wouldn’t be as nervous about it as it is.
First hoop: proper catechesis. In other words, we don’t really need to drink the Cup.
[100.] So that the fullness of the sign may be made more clearly evident to the faithful in the course of the Eucharistic banquet, lay members of Christ’s faithful, too, are admitted to Communion under both kinds, in the cases set forth in the liturgical books, preceded and continually accompanied by proper catechesis regarding the dogmatic principles on this matter laid down by the Ecumenical Council of Trent. [Cf. Ecumenical Council of Trent, Session XXI, 16 July 1562, Decree on Eucharistic Communion, Chapters 1-3: DS 1725-1729; Sacrosanctum Concilium 55; GIRM 282-283.]
To be fair, the CDWDS presumes faith. I would hope that an active discipleship is also part of the lay commitment. Plus, keeping in mind the Lord’s cautionary question to two of his apostles, “Can you drink the cup that I drink or be baptized with the baptism with which I am baptized?”
If apostles are getting queried, I think we lay people can be stand-up men and women and answer it, too.
[101.] In order for Holy Communion under both kinds to be administered to the lay members of Christ’s faithful, due consideration should be given to the circumstances, as judged first of all by the diocesan Bishop. It is to be completely excluded where even a small danger exists of the sacred species being profaned. [Cf. GIRM 283] With a view to wider co-ordination, the Bishops’ Conferences should issue norms, once their decisions have received the recognitio of the Apostolic See through the Congregation for Divine Worship and the Discipline of the Sacraments, especially as regards “the manner of distributing Holy Communion to the faithful under both kinds, and the faculty for its extension”.[Cf. GIRM 283]
My sense is that the CDWDS didn’t really think through that condition, “It is to be completely excluded where even a small danger exists of the sacred species being profaned.”
The truth of it is that there is a greater chance of profanation receiving the host, even in the mouth, than there is of the cup.
Another hoop, that you know isn’t in place for the clergy:
[102.] The chalice should not be ministered to lay members of Christ’s faithful where there is such a large number of communicants[Cf. Sacramentali Communione (1970); Liturgicae Instaurationes 6a] that it is difficult to gauge the amount of wine for the Eucharist and there is a danger that “more than a reasonable quantity of the Blood of Christ remain to be consumed at the end of the celebration”.[GIRM 285a] The same is true wherever access to the chalice would be difficult to arrange, or where such a large amount of wine would be required that its certain provenance and quality could only be known with difficulty, or wherever there is not an adequate number of sacred ministers or extraordinary ministers of Holy Communion with proper formation, or where a notable part of the people continues to prefer not to approach the chalice for various reasons, so that the sign of unity would in some sense be negated.
I’m being hard on the CDWDS and some clergy: I admit it. I think we still have a lot of cultural stuff to overcome in this regard, both with respect to the laity finding some fruitfulness (so to speak) in receiving from the Cup, and in clergy letting it happen. Even if there’s a little difficulty involved.