Again, this is not a case of me not understanding the Roman Catholic doctrine of the Eucharist, nor the reasons for including the cup, then excluding the cup then including it again in some places. I realize that Catholics are expected to believe what they are told to believe and questioning the reason is frowned upon. One more time, the reason this came up IN THIS CONTEXT is simply to draw a distinction between what Jesus says to do in remembrance of Him and what gets done by an organization that claims to BE His one, true church. The irony being that one of the major components of the New Covenant - the blood of Christ - is missing in the observance that the faithful receive. No matter the reasons given for why it might have been changed nor the rationalizations for how it really is all the same anyway with just the bread, the startling truth is the blood is what makes atonement for the soul, makes propitiation for sin, and it has been taken out of the "sacrament" for a long time. We tied that in with how it seems Catholics don't really grasp the critical place of the blood in the satisfactory payment for sins and, instead, somehow view their actions as having to add to it to "expiate" their sins in order to be saved.
If it's all the same really, why then was the cup added back after hundreds of years? If "partaking in just the consecrated bread or cup are the same", what changed the magesterium's mind after VII that now includes the cup if the congregant wants it?
Rather than me continuing to explain this ,here is the explanation from New Advent which ANY Catholic would agree...
http://www.newadvent.org/cathen/04175a.htm
Excerpts
Regarding the merits of the Utraquist controversy, if we assume the doctrinal points involved — viz. the absence of a Divine precept imposing Communion under both kinds, the integral presence and reception of Christ under either species, and the discretionary power of the Church over everything connected with the sacraments that is not divinely determined the question of giving or refusing the chalice to the laity becomes purely practical and disciplinary, and is to be decided by a reference to the two fold purpose to be attained, of safeguarding the reverence due to this most august sacrament and of facilitating and encouraging its frequent and fervent reception. Nor can it be doubted that the modern Catholic discipline best secures these ends. The danger of spilling the Precious Blood and of other forms of irreverence; the inconvenience and delay in administering the chalice to large numbers — the difficulty of reservation for Communion outside of Mass: the not unreasonable objection on hygienic and other grounds, to promiscuous drinking from the same chalice, which of itself alone would act as a strong deterrent to frequent Communion in the case of a great many otherwise well-disposed people; these and similar “weighty and just reasons” against the Utraquist practice are more than sufficient to justify the Church in forbidding it. Of the doctrinal points mentioned above, the only one that need be discussed here is the question of the existence or non-existence of a Divine precept imposing Communion sub utraque. Of the texts brought forward by Utraquists in proof of such a precept, the command, “Drink ye all of this” (Matthew 26:27), and its equivalent in St. Luke (xxii, 17, i.e. supposing the reference here to be to the Eucharistic and not to the paschal cup), cannot fairly be held to apply to any but those present those on the occasion, and to them only for that particular occasion. Were one to insist that Christ’s action in administering Holy Communion under both kinds to the Apostles at the Last Supper was intended to lay down a law for all future recipients, he should for the same reason insist that several other temporary and accidental circumstances connected with the first celebration of the Eucharist (e.g. the preceding paschal rites, the use of unleavened bread, the taking of the Sacred Species by the recipients themselves) were likewise intended to be obligatory for all future celebrations. The institution under both kinds, or the separate consecration of the bread and wine, belongs essentially, in Catholic opinion, to the sacrificial, as distinct from the sacramental, character of the Eucharist; and when Christ in the words “Do this for a commemoration of me” (Luke 22:19), gave to the Apostles both the command and the power to offer the Eucharistic sacrifice, they understood Him merely to impose upon them and their successors in the priesthood the obligation of sacrificing sub utraque. This obligation the Church has rigorously observed.
In John 6:54, Christ says: “Except you eat the flesh of the Son of man and drink his blood, you shall not have life in you” but in verses 52 and 59 he attributes life eternal to the eating of “this bread” (which is “my flesh for the life of the world”, without mention of the drinking of His blood: “if anyone eat of this bread he shall live forever”. Now the Utraquist interpretation would suppose that in verse 54 Christ meant to emphasize the distinction between the mode of reception “by eating” and the mode of reception “by drinking”, and to include both modes distinctly in the precept He imposes. But such literalism, extravagant in any connection, would result in this case in putting verse 54 in opposition to 52 and 59, interpreted in the same rigid way. From which we may infer that whatever special significance attached to the form of expression employed in verse 54, Christ did not have recourse to that form for the purpose of promulgating a law of Communion sub utraque. The twofold expression is employed by Christ in order to heighten the realism of the promise — to emphasize more vividly the reality of the Eucharistic presence, and to convey the idea that His Body and Blood were to be the perfect spiritual aliment, the food and drink, of the faithful. In the Catholic teaching on the Eucharist this meaning is fully verified. Christ is really and integrally received under either kind; and from the sacramental point of view it is altogether immaterial whether this perfect reception takes place after the analogy in the natural order of solid or of liquid food alone, or after the analogy of both combined (cf. III below). In 1 Corinthians 11:28, to which Utraquists sometimes appeal, St. Paul is concerned with the preparation required for a worthy reception of the Eucharist. His mention of both species, “the bread and chalice”, is merely incidental, and implies nothing more than the bare fact that Communion under both kinds was the prevailing usage in Apostolic times. From the verse immediately preceding (27) a difficulty might be raised against the dogmatic presuppositions of the great majority of Utraquists, and an argument advanced in proof of the Catholic doctrine of the integral presence and reception of Christ under either species. “Whosoever”, says the Apostle, “shall eat this bread or drink the chalice of the Lord unworthily, shall be guilty of the body and of the blood of the Lord” i.e. whoever receives either unworthily is guilty of both. But it is unnecessary to insist on this argument in defence of the Catholic position. We are justified in concluding that the N.T. contains no proof of the existence of a Divine precept binding the faithful to Communicate under both kinds. It will appear, further, from the following historical survey, that the Church has never recognized the existence of such a precept.