Thomas Aquinas, Summa Theologiae

Objection 1: It seems that this is not the proper form of this sacrament: "This is My body." For the effect of a sacrament ought to be expressed in its form. But the effect of the consecration of the bread is the change of the substance of the bread into the body of Christ, and this is better expressed by the word "becomes" than by "is." Therefore, in the form of the consecration we ought to say: "This becomes My body."

Objection 2: Further, Ambrose says (De Sacram. iv), "Christ's words consecrate this sacrament. What word of Christ? This word, whereby all things are made. The Lord commanded, and the heavens and earth were made. " Therefore, it would be a more proper form of this sacrament if the imperative mood were employed, so as to say: "Be this My body."

Objection 3: Further, that which is changed is implied in the subject of this phrase, just as the term of the change is implied in the predicate. But just as that into which the change is made is something determinate, for the change is into nothing else but the body of Christ, so also that which is converted is determinate, since only bread is converted into the body of Christ. Therefore, as a noun is inserted on the part of the predicate, so also should a noun be inserted in the subject, so that it be said: "This bread is My body."

Objection 4: Further, just as the term of the change is determinate in nature, because it is a body, so also is it determinate in person. Consequently, in order to determine the person, it ought to be said: "This is the body of Christ."

Objection 5: Further, nothing ought to be inserted in the form except what is substantial to it. Consequently, the conjunction "for" is improperly added in some books, since it does not belong to the substance of the form.

On the contrary, our Lord used this form in consecrating, as is evident from Mt. 26:26.

I answer that, This is the proper form for the consecration of the bread. For it was said (Article 1) that this consecration consists in changing the substance of bread into the body of Christ. Now the form of a sacrament ought to denote what is done in the sacrament. Consequently the form for the consecration of the bread ought to signify the actual conversion of the bread into the body of Christ. And herein are three things to be considered: namely, the actual conversion, the term "whence," and the term "whereunto."

Now the conversion can be considered in two ways: first, in "becoming," secondly, in "being." But the conversion ought not to be signified in this form as in "becoming," but as in "being." First, because such conversion is not successive, as was said above (Question 75, Article 7), but instantaneous; and in such changes the "becoming" is nothing else than the "being." Secondly, because the sacramental forms bear the same relation to the signification of the sacramental effect as artificial forms to the representation of the effect of art. Now an artificial form is the likeness of the ultimate effect, on which the artist's intention is fixed ;. just as the art-form in the builder's mind is principally the form of the house constructed, and secondarily of the constructing. Accordingly, in this form also the conversion ought to be expressed as in "being," to which the intention is referred.

And since the conversion is expressed in this form as in "being," it is necessary for the extremes of the conversion to be signified as they exist in the fact of conversion. But then the term "whereunto" has the proper nature of its own substance; whereas the term "whence" does not remain in its own substance, but only as to the accidents whereby it comes under the senses, and can be determined in relation to the senses. Hence the term "whence" of the conversion is conveniently expressed by the demonstrative pronoun, relative to the sensible accidents which continue; but the term "whereunto" is expressed by the noun signifying the nature of the thing which terminates the conversion, and this is Christ's entire body, and not merely His flesh; as was said above (Question 76, Article 1, ad 2). Hence this form is most appropriate: "This is My body."

Reply to Objection 1: The ultimate effect of this conversion is not a "becoming" but a "being," as stated above, and consequently prominence should be given to this in the form.

Reply to Objection 2: God's word operated in the creation of things, and it is the same which operates in this consecration, yet each in different fashion: because here it operates effectively and sacramentally, that is, in virtue of its signification. And consequently the last effect of the consecration must needs be signified in this sentence by a substantive verb of the indicative mood and present time. But in the creation of things it worked merely effectively, and such efficiency is due to the command of His wisdom; and therefore in the creation of things the Lord's word is expressed by a verb in the imperative mood, as in Gn. 1:3: "Let there be light, and light was made."

Reply to Objection 3: The term "whence" does not retain the nature of its substance in the "being" of the conversion, as the term "whereunto" does. Therefore there is no parallel.

Reply to Objection 4: The pronoun "My," which implicitly points to the chief person, i.e. the person of the speaker, sufficiently indicates Christ's person, in Whose person these words are uttered, as stated above (Article 1).

Reply to Objection 5: The conjunction "for" is set in this form according to the custom of the Roman Church, who derived it from Peter the Apostle; and this on account of the sequence with the words preceding: and therefore it is not part of the form, just as the words preceding the form are not.

Articulus 2

Argumentum 1

Ad secundum sic proceditur. Videtur quod haec non sit conveniens forma consecrationis panis, hoc est corpus meum.

Per formam enim sacramenti debet exprimi sacramenti effectus.

Sed effectus qui fit in consecratione panis, est conversio substantiae panis in corpus christi, quae magis exprimitur per hoc verbum fit, quam per hoc verbum est. Ergo in forma consecrationis deberet dici, hoc fit corpus meum.

Argumentum 2

Praeterea, Ambrosius dicit, in libro de sacramentis, sermo christi hoc conficit sacramentum. Quis sermo christi? hic quo facta sunt omnia, jussit dominus et facta sunt caeli et terra.

Ergo et forma huius sacramenti convenientior esset per verbum imperativum, ut diceretur, hoc sit corpus meum.

Argumentum 3

Praeterea, per subiectum huius locutionis importatur illud quod convertitur, sicut per praedicatum importatur conversionis terminus. Sed, sicut est determinatum id in quod fit conversio, non enim fit conversio nisi in corpus christi; ita est determinatum id quod convertitur, non enim convertitur in corpus christi nisi panis. Ergo, sicut ex parte praedicati ponitur nomen, ita ex parte subiecti debet poni nomen, ut dicatur, hic panis est corpus meum.

Argumentum 4

Praeterea, sicut id in quod terminatur conversio est determinatae naturae, quia est corpus; ita etiam est determinatae personae. Ergo, ad determinandam personam, debet dici, hoc est corpus christi.

Argumentum 5

Praeterea, in verbis formae non debet poni aliquid quod non sit de substantia eius.

Inconvenienter ergo additur in quibusdam libris haec coniunctio enim, quae non est de substantia formae.

Sed Contra

Sed contra est quod dominus hac forma in consecrando est usus, ut patet Matth. XXVI.

Corpus

Respondeo dicendum quod haec est conveniens forma consecrationis panis.

Dictum est enim quod haec consecratio consistit in conversione substantiae panis in corpus christi. Oportet autem formam sacramenti significare id quod in sacramento efficitur.

Unde et forma consecrationis panis debet significare ipsam conversionem panis in corpus christi. In qua tria considerantur, scilicet ipsa conversio, et terminus a quo, et terminus ad quem.

Conversio autem potest considerari dupliciter, uno modo, ut in fieri; alio modo, ut in facto esse. Non autem debuit significari conversio in hac forma ut in fieri, sed ut in facto esse. Primo quidem, quia haec conversio non est successiva, ut supra habitum est, sed instantanea, in huiusmodi autem mutationibus fieri non est nisi factum esse. Secundo, quia ita se habent formae sacramentales ad significandum effectum sacramenti, sicut se habent formae artificiales ad repraesentandum effectum artis. Forma autem artificialis est similitudo ultimi effectus in quem fertur intentio artificis, sicut forma artis in mente aedificatoris est forma domus aedificatae principaliter, aedificationis autem per consequens. Unde et in hac forma debet exprimi conversio ut in facto esse, ad quod fertur intentio.

Et quia ipsa conversio exprimitur in hac forma ut in facto esse, necesse est quod extrema conversionis significentur ut se habent in facto esse conversionis. Tunc autem terminus in quem habet propriam naturam suae substantiae, sed terminus a quo non manet secundum suam substantiam, sed solum secundum accidentia, quibus sensui subiacet, et ad sensum determinari potest. Unde convenienter terminus conversionis a quo exprimitur per pronomen demonstrativum relatum ad accidentia sensibilia, quae manent. Terminus autem ad quem exprimitur per nomen significans naturam eius in quod fit conversio, quod quidem est totum corpus christi, et non sola caro eius, ut dictum est.

Unde haec forma est convenientissima, hoc est corpus meum.

Ad 1

Ad primum ergo dicendum quod fieri non est ultimus effectus huius consecrationis, sed factum esse ut dictum est.

Et ideo hoc potius exprimi debet in forma.

Ad 2

Ad secundum dicendum quod sermo dei operatus est in creatione rerum, qui etiam operatur in hac consecratione, aliter tamen et aliter. Nam hic operatur sacramentaliter, idest secundum vim significationis. Et ideo oportet in hoc sermone significari ultimum effectum consecrationis per verbum substantivum indicativi modi et praesentis temporis. Sed in creatione rerum operatus est solum effective, quae quidem efficientia est per imperium suae sapientiae. Et ideo in creatione rerum exprimitur sermo dominicus per verbum imperativi modi, secundum illud Gen. I, fiat lux, et facta est lux.

Ad 3

Ad tertium dicendum quod terminus a quo in ipso facto esse conversionis non retinet naturam suae substantiae, sicut terminus ad quem. Et ideo non est simile.

Ad 4

Ad quartum dicendum quod per hoc pronomen meum, quod includit demonstrationem primae personae, quae est persona loquentis, sufficienter exprimitur persona christi, ex cuius persona haec proferuntur, ut dictum est.

Ad 5

Ad quintum dicendum quod haec coniunctio enim apponitur in hac forma secundum consuetudinem Romanae ecclesiae a beato Petro apostolo derivatam. Et hoc propter continuationem ad verba praecedentia. Et ideo non est de forma, sicut nec praecedentia formam.