For modern generations, the Council of Trent may not have been mentioned in their doctrinal formation which emphasizes that “nothing is lost by the body being received by the people without the blood: because the priest both offers and receives the blood in the name of all, and the whole Christ is present under either species” (Summa Theologiae, III, q. 80, a. 12, ad 3). So, under the species of bread there is also present, by concomitance, the precious blood.
The purpose, then, of receiving Holy Communion under both kinds, is not that the faithful receive more grace than when they receive it under one kind alone, but that the faithful are enabled to appreciate vividly the value of the sign. Sadly, this distinction has not always been made clear and some people, when not offered Holy Communion under both kinds, have expressed a sense of bewilderment, even thwarted entitlement, or a feeling that Holy Communion under one kind alone was, to some extent, deficient.
Bishops conferences and diocesan bishops, in particular, are the key to ensuring locally that Holy Communion is distributed with reverence and avoidance of misunderstanding.
“Redemptionis Sacramentum” makes clear that the slightest danger of the sacred species being profaned is to be avoided (101). It also expresses concern about the “detriment of so great a mystery” (106). While “profanation” and the “detriment of so great a mystery” suggest different levels of Eucharistic abuse, both levels are expressly mentioned so that they will be avoided.