P.S. from the Catholic Encyclopedia
The sacramental form or the words of consecration
In proceeding to verify the form, which is always made up of words, we may start from the dubitable fact, that Christ did not consecrate by the mere fiat of His omnipotence, which found no expression in articulate utterance, but by pronouncing the words of Institution: “This is my body . . . this is my blood”, and that by the addition: “Do this for a commemoration of me”, He commanded the Apostles to follow His example. Were the words of Institution a mere declarative utterance of the conversion, which might have taken place in the “benediction” unannounced and articulately unexpressed, the Apostles and their successors would, according to Christ’s example and mandate, have been obliged to consecrate in this mute manner also, a consequence which is altogether at variance with the deposit of faith. It is true, that Pope Innocent III (De Sacro altaris myst., IV, vi) before his elevation to the pontificate did hold the opinion, which later theologians branded as “temerarious”, that Christ consecrated without words by means of the mere “benediction”. Not many theologians, however, followed him in this regard, among the few being Ambrose Catharinus, Cheffontaines, and Hoppe, by far the greater number preferring to stand by the unanimous testimony of the Fathers. Meanwhile,** Innocent III also insisted most urgently that at least in the case of the celebrating priest, the words of Institution were prescribed as the sacramental form**. It was, moreover, not until its comparatively recent adherence in the seventeenth century to the famous “Confessio fidei orthodoxa” of Peter Mogilas (cf. Kimmel, “Monum. fidei eccl. orient.”, Jena, 1850, I, p. 180), that the Schismatical Greek Church adopted the view, according to which the priest does not at all consecrate by virtue of the words of Institution, but only by means of the Epiklesis occurring shortly after them and expressing in the Oriental Liturgies a petition to the Holy Spirit, “that the bread and wine may be converted into the Body and Blood of Christ”. Were the Greeks justified in maintaining this position, the immediate result would be, that the Latins who have no such thing as the Epiklesis in their present Liturgy, would possess neither the true Sacrifice of the Mass nor the Holy Eucharist. Fortunately,** however, the Greeks can be shown the error of their ways from their own writings, since it can be proved, that they themselves formerly placed the form of Transubstantiation in the words of Institution. **…
…The objection that the mere historical recitation of the words of Institution taken from the narrative of the Last Supper possesses no intrinsic consecratory force, would be well founded, did the priest of the Latin Church merely intend by means of them to narrate some historical event rather than pronounce them with the practical purpose of effecting the conversion, or if he pronounced them in his own name and person instead of the Person of Christ, whose minister and instrumental cause he is.** Neither of the two suppositions holds in the case of a priest who really intends to celebrate Mass**. Hence, though **the Greeks may in the best of faith go on erroneously maintaining that they consecrate exclusively in their Epiklesis, they do, nevertheless, as in the case of the Latins, actually consecrate by means of the words of Institution contained in their Liturgies, if Christ has instituted these words as the words of consecration and the form of the sacrament. We may in fact go a step farther and assert, that the words of Institution constitute the only and wholly adequate form of the Eucharist **and that, consequently, the words of the Epiklesis possess no inherent consecratory value…
Though this opinion cannot be condemned as erroneous in faith, since it allows to the words of Institution their essential, though partial, consecratory value, appears nevertheless to be intrinsically repugnant. For, since the act of Consecration cannot remain, as it were, in a state of suspense, but is completed in an instant of time, there arises the dilemma: Either the words of Institution alone and, therefore, not the Epiklesis, are productive of the conversion, or the words of the Epiklesis alone have such power and not the words of Institution. Of more considerable importance is the circumstance that the whole question came up for discussion in the council for union held at Florence in 1439. Pope Eugene IV urged the Greeks to come to a unanimous agreement with the Roman faith and subscribe to the words of Institution as alone constituting the sacramental form, and to drop the contention that the words of the Epiklesis also possessed a partial consecratory force. But when the Greeks, not without foundation, pleaded that a dogmatic decision would reflect with shame upon their whole ecclesiastical past, the ecumenical synod was satisfied with the oral declaration of Cardinal Bessarion recorded in the minutes of the council for 5 July, 1439 (P.G., CLXI, 491), namely, that the Greeks follow the universal teaching of the Fathers, especially of “blessed John Chrysostom, familiarly known to us”, according to whom** the “Divine words of Our Redeemer contain the full and entire force of Transubstantiation”. **
newadvent.org/cathen/05584a.htm
The “intent” of the Priest is in celebrating the Mass, and the words of consecration are those same words as spoken by Christ.