Some Protestants claim that the early Church father Theodoret denied transubstantiation, citing the following excerpt:
“The mystical emblems of the body and blood of Christ continue in their original essence and form, they are visible and tangible as they were before [the consecration]; but the contemplation of the spirit and of faith sees in them that which they have become, and they are adored also as that which they are to believers.” (Theodoret, Dialogue ii, Opera ed. Hal. tom. iv p. 126).
Did Theodoret deny transubstantiation? No. Let’s look at this quote in its proper context (emphases mine):
Theodoret/Orthodoxus— I will however endeavour to point out to you several instances of substances which are mixed without being confounded, and remain unimpaired….
Orthodoxus— Tell me now; the mystic symbols which are offered to God by them who perform priestly rites, of what are they symbols? Eranistes.— Of the body and blood of the Lord. Orth.— Of the real body or not? Eran.— The real. Orth.— Good. For there must be the archetype of the image. So painters imitate nature and paint the images of visible objects. Eran.— True. Orth.— If, then, the divine mysteries are antitypes of the real body, therefore even now the body of the Lord is a body, not changed into nature of Godhead, but filled with divine glory. Eran.— You have opportunely introduced the subject of the divine mysteries for from it I shall be able to show you the change of the Lord’s body into another nature. Answer now to my questions. Orth.— I will answer. Eran.— What do you call the gift which is offered before the priestly invocation? Orth.— It were wrong to say openly; perhaps some uninitiated are present. Eran.— Let your answer be put enigmatically. Orth.— Food of grain of such a sort. Eran.— And how name we the other symbol? Orth.— This name too is common, signifying species of drink. Eran.— And after the consecration how do you name these? Orth.— Christ’s body and Christ’s blood. Eran.— And do you believe that you partake of Christ’s body and blood? Orth.— I do. Eran.— As, then, the symbols of the Lord’s body and blood are one thing before the priestly invocation, and after the invocation are changed and become another thing; so the Lord’s body after the assumption is changed into the divine substance. Orth.— You are caught in the net you have woven yourself. For even after the consecration the mystic symbols are not deprived of their own nature; they remain in their former substance figure and form; they are visible and tangible as they were before. But they are regarded as what they have become, and believed so to be, and are worshipped as being what they are believed to be. Compare then the image with the archetype, and you will see the likeness, for the type must be like the reality. For that body preserves its former form, figure, and limitation and in a word the substance of the body; but after the resurrection it has become immortal and superior to corruption; it has become worthy of a seat on the right hand; it is adored by every creature as being called the natural body of the Lord.
Theodoret is not even discussing the Eucharist itself specifically but rather only analogously to the human body of Christ. He is debating a heretic who believes that the risen Jesus was/is no longer human and thus had/has no human body.
If Theodoret does not believe in transubstantiation, then why does he say that the Eucharistic elements “are worshipped (Greek word proskuvnei’n, according to Protestant scholar Philip Schaff, History of the Christian Church, 3, 501-502)”? Compare the Greek word with how it is used in the Bible
Theodoret also uses the language of being, not mere representation: “But they are regarded as what they have become, and believed so to be, and are worshipped as being what they are believed to be.” Yes, earlier on in the dialogue Theodoret refers to the Eucharist as “mystic symbols,” but symbols in the Greek Eastern theology can communicate the real presence of God (cf. icons in the Eastern churches). The Eucharist is a unique mystic symbol in that it embodies or is the Body and Blood of Christ, not merely an abstract representation of it.Theodoret explains what he means by substance. He uses other words like “figure” and “form” and “visible” and “tangible.” These terms are exactly how a Catholic would refer to the bread and wine after the consecration: the bread and wine are visible and tangible forms of the reality of Jesus Christ’s body and blood.And why does Theodoret refuse to “say openly” the name of “the gift which is offered before the priestly invocation”? For fear that “some uninitiated are present.” Seems Theodoret is afraid to say “bread” and “wine.” Why? Seems he believes that the “uninitiated” will be led astray by the use of those words. Seems very Catholic to me.
Even the heretics of this time did not deny transubstantiation but wished to use it to promote their Christological heresies.