Justin Martyr on the Eucharist

. . . and the early church. From the First Apology (c. AD150?), §66-67:

“And this food is called among us Eukaristia [the Eucharist], of which no one is allowed to partake but the man who believes that the things which we teach are true, and who has been washed with the washing that is for the remission of sins, and unto regeneration, and who is so living as Christ has enjoined. For not as common bread and common drink do we receive these; but in like manner as Jesus Christ our Saviour, having been made flesh by the Word of God, had both flesh and blood for our salvation, so likewise have we been taught that the food which is blessed by the prayer of His word, and from which our blood and flesh by transmutation are nourished, is the flesh and blood of that Jesus who was made flesh. For the apostles, in the memoirs composed by them, which are called Gospels, have thus delivered unto us what was enjoined upon them; that Jesus took bread, and when He had given thanks, said, “This do ye in remembrance of Me, this is My body;” and that, after the same manner, having taken the cup and given thanks, He said, “This is My blood;” and gave it to them alone. Which the wicked devils have imitated in the mysteries of Mithras, commanding the same thing to be done. For, that bread and a cup of water are placed with certain incantations in the mystic rites of one who is being initiated, you either know or can learn.

“And we afterwards continually remind each other of these things. And the wealthy among us help the needy; and we always keep together; and for all things wherewith we are supplied, we bless the Maker of all through His Son Jesus Christ, and through the Holy Ghost. And on the day called Sunday, all who live in cities or in the country gather together to one place, and the memoirs of the apostles or the writings of the prophets are read, as long as time permits; then, when the reader has ceased, the president verbally instructs, and exhorts to the imitation of these good things. Then we all rise together and pray, and, as we before said, when our prayer is ended, bread and wine and water are brought, and the president in like manner offers prayers and thanksgivings, according to his ability, and the people assent, saying Amen; and there is a distribution to each, and a participation of that over which thanks have been given, and to those who are absent a portion is sent by the deacons. And they who are well to do, and willing, give what each thinks fit; and what is collected is deposited with the president, who succours the orphans and widows and those who, through sickness or any other cause, are in want, and those who are in bonds and the strangers sojourning among us, and in a word takes care of all who are in need. But Sunday is the day on which we all hold our common assembly, because it is the first day on which God, having wrought a change in the darkness and matter, made the world; and Jesus Christ our Saviour on the same day rose from the dead. For He was crucified on the day before that of Saturn (Saturday); and on the day after that of Saturn, which is the day of the Sun, having appeared to His apostles and disciples, He taught them these things, which we have submitted to you also for your consideration.”

Aquinas on the Eucharist

“BECAUSE spiritual effects are produced on the pattern of visible effects, it was fitting that our spiritual nourishment should be given us under the appearances of those things that men commonly use for their bodily nourishment, namely bread and wine. And for the further correspondence of spiritual signs with bodily effects, in the spiritual regeneration of Baptism the mystery of the Word Incarnate is united with us otherwise than as it is united in this Sacrament of the Eucharist, which is our spiritual nourishment. In Baptism the Word Incarnate is only virtually contained, but in the Sacrament of the Eucharist we confess Him to be contained substantially, as nourishment must be substantially united with the nourished.

“And because the completion of our salvation was wrought by Christ’s passion and death, whereby His Blood was separated from His Body, therefore the Sacrament of His Body is given us separately under the species of bread, and His Blood under the species of wine.”

. . .

” IT is impossible for the true Body of Christ to begin to be in this Sacrament by local motion, because then it would cease to be in heaven, upon every consecration of this Sacrament; as also because this Sacrament could not then be consecrated except in one place, since one local motion can only have one terminus; also because local motion cannot be instantaneous, but takes time. Therefore its presence must be due to the conversion of the substance of bread into the substance of His Body, and of the substance of wine into the substance of His Blood. This shows the falseness of the opinion of those who say that the substance of bread co-exists with the substance of the Body of Christ in this Sacrament;* also of those who say that the substance of bread is annihilated. If the substance of bread co-exists with the Body of Christ, Christ should rather have said, Here is my Body, than, This is my Body. The word here points to the substance which is seen, and that is the substance of bread, if the bread remain in the Sacrament along with the Body of Christ.

“Every operation of nature presupposes matter, whereby subjects are individuated; hence nature cannot make this subject become that, as for instance, this finger that finger. But matter lies wholly under the power of God, since by that power it is brought into being: hence it may be brought about by divine power that one individual substance shall be converted into another pre-existing substance. By the power of a natural agent, the operation of which extends only to the producing of a change of form and presupposes the existence of the subject of change, this whole is converted into that whole with variation of species and form.* So by the divine power, which does not presuppose matter, but produces it, this matter is converted into that matter, and consequently this individual into that: for matter is the principle of individuation, as form is the principle of species.* Hence it is plain that in the change of the bread into the Body of Christ there is no common subject abiding after the change, since the change takes place in the primary subject [i.e., in the matter], which is the principle of individuation. Yet something must remain to verify the words, This is my body, which are the words significant and effective of this conversion. But the substance does not remain: we must say therefore that what remains is something beside the substance, that is, the accident of bread. The accidents of bread then remain even after the conversion.

“This then is one reason for the accident of bread remaining, that something may be found permanent under the conversion. Another reason is this. If the substance of bread was converted into the Body of Christ, and the accidents of bread also passed away, there would not ensue upon such conversion the being of the Body of Christ in substance where the bread was before: for nothing would be left to refer the Body of Christ to that place. But since the dimensions of bread (quantitas dimensiva panis), whereby the bread held this particular place, remain after conversion, while the substance of bread is changed into the Body of Christ, the Body of Christ comes to be under the dimensions of bread, and in a manner to occupy the place of the bread by means of the said dimensions.”

– Summa Contra Gentiles 4.61; 4.63

” THOSE conditions must be observed which are essential for bread and wine to be. That alone is called wine, which is liquor pressed out of grapes:* nor is that properly called bread, which is not made of grains of wheat. Substitutes for wheaten bread have come into use, and have got the name of bread; and similarly other liquors have come into use as wine: but of no such bread other than bread properly so called, or wine other than what is properly called wine, could this Sacrament possibly be consecrated: nor again if the bread and wine were so adulterated with foreign matter as that the species should disappear.

“A valid Sacrament may be consecrated irrespectively of varieties of bread and wine, when the varieties are accidental, not essential. The alternative of leavened or unleavened bread is an instance of such accidental variety; and therefore different churches have different uses in this respect; and either use may be accommodated to the signification of the Sacrament. Thus as Gregory says in the Register of his Letters*: “The Roman Church offers unleavened bread, because the Lord took flesh without intercourse of the sexes: but other Churches offer leavened bread, because the Word of the Father, clothed in flesh, is at once true God and true man.” Still the use of unleavened bread is the more congruous, as better representing the purity of Christ’s mystical Body, the Church, which is figured in a secondary way (configuratur) in this Sacrament, as the text has it: Christ our passover is sacrificed: therefore let us feast in the unleavened bread of sincerity and truth (1 Cor. v, 7, 8).”

– Summa Contra Gentiles, 4.69

Whether the whole Christ is contained under this sacrament?

Objection 1: It seems that the whole Christ is not contained under this sacrament, because Christ begins to be in this sacrament by conversion of the bread and wine. But it is evident that the bread and wine cannot be changed either into the Godhead or into the soul of Christ. Since therefore Christ exists in three substances, namely, the Godhead, soul and body, as shown above (Question [2], Article [5]; Question [5], Articles [1],3), it seems that the entire Christ is not under this sacrament.

Objection 2: Further, Christ is in this sacrament, forasmuch as it is ordained to the refection of the faithful, which consists in food and drink, as stated above (Question [74], Article [1]). But our Lord said (Jn. 6:56): “My flesh is meat indeed, and My blood is drink indeed.” Therefore, only the flesh and blood of Christ are contained in this sacrament. But there are many other parts of Christ’s body, for instance, the nerves, bones, and such like. Therefore the entire Christ is not contained under this sacrament.

On the contrary, Ambrose says (De Officiis): “Christ is in this sacrament.”

I answer that, It is absolutely necessary to confess according to Catholic faith that the entire Christ is in this sacrament. Yet we must know that there is something of Christ in this sacrament in a twofold manner: first, as it were, by the power of the sacrament; secondly, from natural concomitance. By the power of the sacrament, there is under the species of this sacrament that into which the pre-existing substance of the bread and wine is changed, as expressed by the words of the form, which are effective in this as in the other sacraments; for instance, by the words: “This is My body,” or, “This is My blood.” But from natural concomitance there is also in this sacrament that which is really united with that thing wherein the aforesaid conversion is terminated. For if any two things be really united, then wherever the one is really, there must the other also be: since things really united together are only distinguished by an operation of the mind.

Reply to Objection 1: Because the change of the bread and wine is not terminated at the Godhead or the soul of Christ, it follows as a consequence that the Godhead or the soul of Christ is in this sacrament not by the power of the sacrament, but from real concomitance. For since the Godhead never set aside the assumed body, wherever the body of Christ is, there, of necessity, must the Godhead be; and therefore it is necessary for the Godhead to be in this sacrament concomitantly with His body. Hence we read in the profession of faith at Ephesus (P. I., chap. xxvi): “We are made partakers of the body and blood of Christ, not as taking common flesh, nor as of a holy man united to the Word in dignity, but the truly life-giving flesh of the Word Himself.”

On the other hand, His soul was truly separated from His body, as stated above (Question [50], Article [5]). And therefore had this sacrament been celebrated during those three days when He was dead, the soul of Christ would not have been there, neither by the power of the sacrament, nor from real concomitance. But since “Christ rising from the dead dieth now no more” (Rm. 6:9), His soul is always really united with His body. And therefore in this sacrament the body indeed of Christ is present by the power of the sacrament, but His soul from real concomitance.

Reply to Objection 2: By the power of the sacrament there is contained under it, as to the species of the bread, not only the flesh, but the entire body of Christ, that is, the bones the nerves, and the like. And this is apparent from the form of this sacrament, wherein it is not said: “This is My flesh,” but “This is My body.” Accordingly, when our Lord said (Jn. 6:56): “My flesh is meat indeed,” there the word flesh is put for the entire body, because according to human custom it seems to be more adapted for eating, as men commonly are fed on the flesh of animals, but not on the bones or the like.”

– Summa Theologiae, Third Part, Question 76, Article 1