For very many centuries the Blessed Sacrament has been reserved in one kind, that is in solid and not in liquid form, throughout the Catholic Church. In the West, the Sacred Host alone has been reserved: in the East, the Host is tinged with the Precious Blood, then carefully dried and so reserved. Thus in the Eastern Church there is no reservation of the Sacrament in liquid form: those, who are communicated with It, eat and do not drink.
In the early ages of the Church we find occasional, though not frequent instances of reservation in both kinds. It is clear that the whole Church abandoned reservation in both kinds as the result of her incomparable experience. For Catholics this impressive fact is
decisive. Moreover the Eastern custom shows that the Church in those regions would prefer to reserve in both kinds, but was driven by her own experience to agree with the West and to reserve only in solid form.
Even if we put aside the question of the authority of the whole Church (which, as Catholic Christians, we cannot do), it would be contrary to reason and common sense to ignore the fruit of the age-long experience of so vast a body of Christians as the East and West united.
It is well known that for the first thousand years and more of the Church's life the faithful present at Mass were, given Communion under both kinds. But, during those first thousand years and more, reservation of the Host only was a common and recognised practice from the close of the second century onwards-that is, within a hundred years of the death of the Apostle St. John; it seems, even in those early ages to have been far more common than reservation in both kinds.
Opponents of this practice, being unable to deny this witness of the Church, are content to allege that, since our Lord instituted and gave the Eucharist in both kinds to His Apostles, the Church had no right to give Communion in one kind only, even outside the Mass itself. They often add to this that Communion under one kind is "a mutilated Sacrament," a "half-Communion"; some assert it is no Communion at all.
To the first allegation it is really enough to reply that the Catholic Church, to which our Lord gave complete authority, to which alone He entrusted the Eucharist, to which He promised the perpetual guidance of the Holy Spirit, is a better witness and guide to the mind of Christ than new "schools of thought" which arose some fifteen centuries after His ascension. Anyhow our Lord gave us no other guide, not even the books of the New Testament; for (with the exception of the Apocalypse, which does not allude to the matter) our Lord never even hinted that the books of the New Testament would ever be written at all: still less that they would supersede His Church, to which He gave authority until the end of the world.
We will now reply to the allegation that Communion in one kind is a "half Communion," or no Communion at all, or a mutilation of the Sacrament.
On what principle did the Church first permit, then encourage and finally order reservation in one kind only, that of the Host, whether the species of Wine be dried upon It or not?
It is founded upon the Church's doctrine, which she received from the beginning, that by virtue of consecration, the bread and wine of the Eucharist become really and objectively the Body and Blood of Christ. They become the Body and Blood of Christ as they now are, risen and glorified. It is true that the bread becomes His Body and the wine His Blood. But since His precious Blood can no more be separated from His Body, nor His Body from His Blood, it follows that the Body is present in the Host by virtue of consecration and His Blood by virtue of its inseparability. Likewise the wine becomes His Blood by virtue of the words of consecration and His Body by virtue of its inseparability. Also His human soul is present by virtue likewise of its inseparability from His Body and Blood: and His Divinity by virtue of its inseparability from His humanity. Of course His Divinity is present everywhere: but the presence of His sacred Humanity in the Eucharist gives us a special point towards which we may direct our prayers and worship to His Divinity; exactly as His visible presence as man would give us, if in vouchsafed to grant it to us; as He did to St. Paul on the Damascus road and to St. John in the isle of Patmos.
It follows, therefore, that under each species and under every particle or fragment of each species we have the whole Christ: Christ is whole and entire under either kind, for Christ can no longer be divided: "Christ being raised from the dead dieth no more, death hath no more dominion over Him."
Since Christ cannot be divided, since it is Himself that is present in His Humanity ("He that eateth Me, he shall live by Me"), there can be no such thing as a "half-communion." Either He is present, whole and entire, under either kind, or He is not there at all. The Sacrament cannot possibly be "mutilated." It is either the Sacrament in its entirety or it is no Sacrament at all. But it cannot be "no Sacrament" if the whole Christ is present under either kind, for then we have the outward and visible part and the inward and spiritual; and the Sacrament is constituted in its perfection.
This is called the "law of concomitance." The word concomitance means "existing together." Theologians use the word to express the fact, expounded above, that where one part of the Sacred humanity is, there also are the other parts accompanying it; because the humanity is an inseparable and indivisible whole. Hence, although the special gift of the first element in the Sacrament is our Lord's Body, or Flesh as He calls it in St. John's Gospel, and the special gift of the second element is His Blood, yet where the Body is the Blood is also, and the Soul; and similarly, where the Blood is, there also is the Body and also the Soul; likewise the Divinity by virtue of the Hypostatic Union as it is called. That means the inseparable union of the Divinity with the Humanity in the One Person of the Eternal Son.
This law of concomitance is simply another expression for the indivisibility of Christ as He now is. This doctrine is taught emphatically in St. Paul's indignant question, "Is Christ divided?" It is implied again in the insistence on the "one Lord" in the Epistle to the Ephesians. It is the thesis upon which Heb. ix and x are based. It may be gathered from St. Paul's word on the Eucharist itself, " He that eateth and drinketh unworthily, eateth and drinketh judgment to himself, not discerning the Lord's body." Here the Apostle twice refers to the chalice, yet speaks of discerning the Lord's body, without adding "and blood"; since the former carries the latter with it. This is also the unanimous teaching of the Fathers. Nothing aroused their indignation more than the mere suspicion of dividing Christ.
Catholic theology therefore teaches that, by virtue of the words of consecration, our Lord's Body is present under the form of bread, and by virtue of concomitance His Blood, Soul and Divinity are present equally with It. Similarly in the case of the chalice. It follows that under either kind the whole and entire Christ is received. This conclusion is rigorous and cannot be evaded by any one who believes in the Presence. Why then, it is asked, did our Lord institute the Sacrament in both kinds? For the purpose of the Sacrifice, the anamnesis or "memorial," to "show forth the Lord's death till He come." The separate consecration of the bread and wine is the mystical or "unbloody" sacrifice, as the Fathers call it, not only symbolising the Lord's death, but making it a present fact to us, as it always is to God: so St. John speaks of the vision of the Lamb "as it had been slain" in heaven, and also of "the Lamb slain from the foundation of the world." When our Lord said "Drink ye all of this,'' He was speaking to the Apostles constituting them priests and empowering them to offer the sacrifice, "This do." Hence the celebrant must receive in both kinds to fulfil our Lord's commands and complete the sacrifice. His communion is not only personal and individual, like that of the congregation taken individually, but official. In all other respects our Lord left the details to His Church to which He then and there entrusted the Eucharist. He left us no choice but to follow the teaching and practice of the whole Church.