Article — Prümmer, Manuale Theologiae Moralis
Article I. The Person of the Subject Himself
186. Principle. The subject capable of receiving the Eucharist with fruit is every living baptized human being, provided that he does not voluntarily place an obstacle to grace through mortal sin.
It is said, 1. every living baptized human being, for a dead man cannot receive any sacrament. Hence several Councils88 prohibited the dead from receiving the Eucharist in the mouth and being buried thus. But without prior valid Baptism no sacrament can be received, as is evident from what was said above.
It is said, 2. provided that a man does not voluntarily place an obstacle to grace through mortal sin. For the Eucharist is a sacrament of the living and, according to what was said above in n. 42, can never revive if it was received with consciousness of mortal sin or even without attrition for it.
From what has been said, it follows that the following are capable of the Eucharist:
88 Carthage, A.D. 397, can. 6 (Mansi 3, 881); Hippo, A.D. 393, can. 4; Council in Trullo, A.D. 692, can. 83.
187. 1. Infants.
Because of the words of Christ expressed generally and without limitation: "Unless you eat the flesh of the Son of Man and drink His Blood, you shall not have life in you,"89 Communion was given to infants in the Latin Church until the twelfth century and is given in the Eastern Church even to the present day; hence they successively receive three sacraments, namely, Baptism, Confirmation, and the Eucharist. In the thirteenth century St. Thomas90 taught simply that the Eucharist was not to be given to children before they begin to have some use of reason, so that they can conceive devotion toward this sacrament. The same was established by the Fourth Lateran Council,91 the Council of Trent,92 and the Code of Canon Law, c. 854, §§ 1 and 2: "The Eucharist is not to be administered to children who, because of the weakness of their age, do not yet have knowledge and taste of this sacrament; in danger of death, in order that the Most Holy Eucharist may and ought to be administered to children, it is sufficient that they know how to distinguish the Body of Christ from ordinary food and reverently adore It." The age of those to be admitted to first Eucharistic Communion will be discussed again below in n. 211. But the words of Christ cited above are customarily explained either of the desire for sacramental Communion or of spiritual communion with the Mystical Body of Christ.93
89 John 6:54.
90 S. theol. 3, q. 80, a. 9 ad 3.
92 Session 13, can. 9 on the Eucharist (Denz., n. 891).
93 Cf. S. theol., loc. cit., and q. 73, a. 3.
188. 2. The insane.
Nevertheless, according to the discipline in force, Communion is not given to those who have been perpetually insane, because they are equated with infants94 and because otherwise the sacrament is exposed to the danger of irreverence, while sufficient provision is made for their salvation through Baptism and conditional absolution. But to those who have not been perpetually insane, the Eucharist can be given at the point of death, provided that an interpretative intention may be presumed from their previous life and the sacrament is not exposed to irreverence. But in order to test whether such an insane person can communicate without irreverence, an unconsecrated host should first be given to him; if he swallows it properly, a consecrated host can also be given to him. Concerning this matter St. Thomas95 teaches: "If previously, when [the insane] were in possession of their mind, devotion toward this sacrament appeared in them, this sacrament ought to be given to them at the point of death, unless perhaps there is fear of the danger of vomiting or spitting it out." Moreover, it happens not rarely that those who were insane during life have lucid intervals as death approaches and thus are able to receive Viaticum. In practice, it is sometimes rather difficult to discern whether a man is perfectly insane or rather feeble-minded. Such a man can then receive Viaticum if this can be done without grave danger of irreverence. But outside the point of death, it is better to deny him Communion.
Dying persons deprived of their senses or delirious persons are nearly equated with the insane; they can and ought to receive Viaticum if this is possible without irreverence. To test this possibility, it is useful first to give them a small unconsecrated particle, as was just said concerning the insane. Moreover, it is necessary that from their previous Christian life an intention here and now to receive Viaticum can rightly be presumed in them. Hence a dying person deprived of his senses who previously led a life that was scarcely Christian can indeed be absolved conditionally and receive Extreme Unction; but it is better that Communion not be given to him.
94 Code of Canon Law, c. 88, § 3.
95 S. theol., loc. cit., and q. 80, a. 9.
189. 3. The feeble-minded,96 old persons becoming childlike again, deaf-mutes, etc., can and ought to receive the Eucharist at the point of death, provided that there is no danger of irreverence. Indeed, it is preferable that they communicate sometimes during the year, provided that they can in some measure distinguish the Eucharistic Bread from ordinary bread.
Certain ancient and modern authors speak more harshly concerning deaf-mutes. Certainly, if they have no use of reason at all, they are to be treated like the perpetually insane, concerning whom it was said above; but now they are customarily instructed in special schools and arrive at sufficient instruction, and therefore they can receive the Eucharist like other men.
Scholion. On those who labor under a continual cough or vomiting. Such sick persons are excluded from Communion only if there is a grave danger of vomiting the Communion received. Whether such a danger is truly present can be judged if the vomiting has already ceased for some hours or if an unconsecrated particle previously given was not vomited. If a serious doubt remains, a consecrated host is not to be given to such a sick person. Otherwise, irreverence would easily follow.
96 German: Geistesschwache (the mentally weak).