It is remarkable that for hundreds of years the Church did not find it necessary to formally dogmatize a particular definition of the Holy Eucharist. Despite real differences of expression, significant conflict between theologians and churches did not arise. The one Church was able to comprehend Ambrose, John Chrysostom, and Gregory Nyssen, as well as Tertullian, Origen, and Augustine. At the deep level of liturgy and prayer, the Church was united in a common confession and enactment of the sacramental promises of Christ: “This is my body. This is my blood.” That is to say, the Church was united in the real identification of the consecrated bread and wine with the body and blood of the Savior. It is this sacramental identification that serves as the eucharistic dogma of the Church catholic. Through the supernatural power of consecration, the eucharistic bread and wine not only represent and symbolize, convey and communicate the body and blood; they are the body and blood. The mystery of eucharistic identity is, as Francis J. Hall writes, “the ultimate affirmation of catholic doctrine in every age” (Dogmatic Theology, IX:119).
The dogma of real identification must be distinguished from the doctrine of the real presence. The latter is often expounded as if it were the revealed premise of the Holy Eucharist; but as Hall explains, “Our Lord did not say, ‘My body is present in, with and under this,’ but ‘This is My body’” (IX:138). The real presence is an inference from the eucharistic dogma. The risen Christ is present in the Eucharist because his body and blood are present, and his body and blood are present because the consecrated bread and wine are his body and blood. “Christ is in that Sacrament,” affirms St Ambrose, “because it is the Body of Christ” (De mysteriis 9.5).
In the Eastern Church the mystery of real identification came to dogmatic expression at the Second Council of Nicaea (A.D. 787). The council was convened to address the heresy of iconoclasm—the denial that images of Jesus and the saints may be properly venerated and reverenced. The iconoclasts maintained that a true icon is identical (homoousios) with its prototype. In Scripture and the theological tradition, Jesus Christ is named the Image of the Father. He serves as this perfect image because he is eternally begotten by and consubstantial with the Father. Only thus does he reveal who God is; only thus may he be given the worship, adoration, and devotion properly offered to the Almighty Creator. A material painting of Jesus, as with all icons, does not enjoy a oneness of being with the object it depicts. The image may point us to its prototype, but it cannot make him truly present; hence the opposition of the iconoclasts to the veneration of icons. They did, however, recognize one divinely-instituted image of the incarnate Son—his eucharistic body and blood. The Eucharist perfectly images Christ because it is identical in essence with Christ, who in turn is identical in essence with his Father and is therefore worthy of divine worship and reverence.1
The iconodules did not take issue with the iconoclastic claim that the Holy Gifts are homoousios with the body and blood of the risen Christ. The iconodules and iconoclasts shared a common liturgy and a common understanding of the eucharistic identification and presence. But clearly the iconodules could not allow the iconoclasts to appropriate the Eucharist as an icon of Christ. At Nicaea II the deacon Epiphanius read a document that was gladly received by the orthodox bishops:
Thus, it has been clearly demonstrated that nowhere did either the Lord, or the Apostles, or the Fathers call the bloodless sacrifice, offered through the priest, “an icon,” but rather “this very body” and “this very blood.” … These noble ones, however, in their desire to abolish the sight of the venerable icons, have introduced indirectly another icon—which is not an icon but body and blood…. Afterwards, leaving aside falsehood, they touch for a moment upon the truth, saying that the bread does become the divine body. But, if the bread is an icon of the body, it is impossible for it to be the divine body itself. (Quoted in Daniel J. Sahas, Icons and Logos, pp. 95-96)
To speak of the Eucharist as icon implies a distinction between the sacramental forms and Christ’s glorified body, between image and prototype. But the distinction does not obtain. The Eucharist just is the flesh of Christ. “These we do not understand [as being] two,” St Nicephorus states, “but we believe that they become one and the same [body of Christ]” (quoted in John Travis, In Defense of the Faith, p. 117). With the conciliar assertion that the consecrated elements simply are the body and blood, the use of “symbol,” “figure,” and “image” to characterize the Holy Gifts largely disappears in Byzantine Christianity.
In the Latin West the dogma of real identification was clarified via a more complicated route. Through the writings of St Augustine it had become firmly established to speak of the consecrated elements as signs through which we are given access to spiritual realities. What is unclear, however, is whether Augustine’s symbolic approach allows for a direct, realistic affirmation of identity between the sanctified bread and wine and the body and blood of the Lord. The Latin formulation of transubstantiation, culminating in the Council of Trent, might well be understood as the Church liberating itself from the inadequacies of Augustine’s eucharistic theology.
The Tridentine eucharistic dogma is summarily expressed in the statement that “through the Consecration of the bread and wine a conversion is made of the whole substance of the bread into the substance of the Body of Christ Our Lord, and of the whole substance of the wine into the substance of his Blood” (Decree Concerning the Most Holy Sacrament of the Eucharist, Chapter III). Precisely what did Trent define? Contemporary interpreters generally agree that Trent did not formally impose Aristotelian philosophy. Colman O’Neill, for example, asserts that the Tridentine understanding of “substance” should be interpreted pre-philosophically. At the level of commonsense, substance answers the question “What is that thing?” Thus: What is the wafer before the consecration? Bread. What is it after the consecration? The body of Christ. “By her dogmatic statement,” O’Neill writes, “the Church makes clear the sense in which she reads the scriptural report of Christ’s words at the Last Supper: the word ‘is’ indicates, as a result of Christ’s power, real identity between what lay on the table and his body” (Colman O’Neill, New Approaches to the Eucharist, p. 98). When the Council declares that the whole substance of the bread is converted into the whole substance of the body of Christ, it is simply insisting that the bread has become the body of Christ. It is reiterating, in more sophisticated fashion, the eucharistic dogma as held by the Church since the Apostles, the dogma of real identification.
However, we must also note, as we observed earlier, the frequent use of the preposition “under” in the decrees: The body and blood are contained “under the appearances of bread and wine.” In Chapter III alone this phrase is found ten times. The Western explication of the eucharistic dogma is constructed on an opposition between external appearances and invisible reality, precisely at the point where they can presumably be separated. Christopher Conn maintains that Trent does not teach sacramental identification. It is metaphysically impossible for a piece of bread, he states, to become “identical with a distinct, pre-existing substance (the body of Christ)” (“Transubstantiation and the Real Presence,” Philosophy and Theology 15 ). The substance of bread must be replaced by the substance of body. A fundamental dualism is therefore integral to the Tridentine definitions. Before the consecration, we perceive the substances of bread and wine resting on the altar (appearance and substance in indivisible unity); after the consecration, we still sensibly perceive bread and wine but by faith now apprehend the substances of body and blood (appearance and substance having been sundered). Yet must this dualism be given dogmatic status? Michael Dummett has articulated the misgivings of many regarding the scholastic formulation of transubstantiation:
The consecrated elements are, as it were, merely the discarded husk of the bread and wine earlier present, and have no more intimate connection with the Body and Blood of Christ than that. It is as if the bread and wine have stepped aside to make room for Christ’s Body and Blood, which could not otherwise be present, and, in so stepping aside, have, so to speak, left their mortal remains behind. (“The Intelligibility of Eucharistic Doctrine,” in The Rationality of Religious Belief, p. 236)
Sacramental identification solves the problem of “discarded husks” by refusing philosophical explanation. The true mystery lies in dominical determination, not in metaphysical wizardry.
In the early twentieth century a little known debate on this question occurred among Greek Orthodox theologians. Chrestos Androutsos defined the Eucharist as “that divinely instituted sacrament in which Jesus Christ is present actually and really under the forms of bread and wine” (emphasis mine). Constantine Dyobouniotes attacked this formulation:
This expression [“under the forms”] … is based on the Roman doctrine … of transubstantiation, and cannot be accepted in the Eastern Church, whose Fathers teach that the bread and wine are changed (converted), into the Body and Blood of Christ … (Our Lord) said: “Take eat, this is my body,” not “under this is my body.” … If we repudiate in every way the Protestant attempt to interpret these words to mean this “represents, stands for” … how much less may we dare to substitute under this for His word, “this?” … The Eastern Church does not recognize that the substance of the bread and wine is changed into the Body and Blood of Christ while the accidents remain, under which the Body and Blood of Christ exist, but simply says that the bread and wine are changed into the Body and Blood of Christ by the descent of the Holy Spirit, through whom these things surpassing reason and understanding are achieved…. All of the bread and wine is changed into the Body and Blood of Christ, and not only a part of them. (Quoted in Frank Gavin, Some Aspects of Contemporary Greek Orthodox Thought, pp. 330-333)2
It is evident that Dyobouniotes is seeking here to expound a nondualistic understanding of the real identity, an understanding that is not dependent on the separation of accident and substance. The body and blood of Christ do not exist “in” or “under” the consecrated elements: “Each particle of bread and wine is Christ” (341-42, n. 7). This affirmation recalls the Greek fathers who envisioned the eucharistic transmutation as a “cultic and sacramental incarnation of Christ” (Edward Schillebeeckx, The Eucharist, p. 68). Bread and wine are appropriated by the Spirit and changed, in their totality, into the body and blood. Dyobouniotes’ contemporaries, however, sided with Androutsos and reaffirmed the language of transubstantiation to describe the eucharistic presence. I think it would be accurate to say that Orthodox theologians today would be more sympathetic to the concerns of Dyobouniotes, as they seek to restate the doctrine of the Eucharist apart from traditional Western categories.3 But surely both Catholic and Orthodox theologians would agree on the fundamental dogmatic assertion: the eucharistic gifts are, in truth and reality, the body and blood of the Lord Jesus Christ.
(Pontifications, 15 April 2004; rev.)
 See Jaroslav Pelikan, The Spirit of Eastern Christendom, pp. 93-94, 109-110, 113; Jaroslav Pelikan, Imago Dei, pp. 58-59; Darwell Stone, A History of the Doctrine of the Holy Eucharist, I:147-151; Stephen Gero, “The Eucharistic Doctrine of the Byzantine Iconoclasts and its Sources.”
 Cf. Christiaan Kappes, “The biblical origin and Late-Antique invention (c. 536) of the Eucharistic term and definition ‘Transubstantiation.'”
 See, e.g., “Transmutation or Transubstantiation.”