From the Canons of Trent, The Thirteenth Session:
CHAPTER I.
On the real presence of our Lord Jesus Christ in the most holy sacrament of the Eucharist.
In the first place, the holy Synod teaches, and openly and simply professes, that, in the august sacrament of the holy Eucharist, after the consecration of the bread and wine, our Lord Jesus Christ, true God and man, is truly, really, and substantially contained under the species of those sensible things. For neither are these things mutually repugnant,-that our Saviour Himself always sitteth at the right hand of the Father in heaven, according to the natural mode of existing, and that, nevertheless, He be, in many other places, sacramentally present to us in his own substance, by a manner of existing, which, though we can scarcely express it in words, yet can we, by the understanding illuminated by faith, conceive, and we ought most firmly to believe, to be possible unto God: for thus all our forefathers, as many as were in the true Church of Christ, who have treated of this most holy Sacrament, have most openly professed, that our Redeemer instituted this so admirable a sacrament at the last supper, when, after the blessing of the bread and wine, He testified, in express and clear words, that He gave them His own very Body, and His own Blood; words which,-recorded by the holy Evangelists, and afterwards repeated by Saint Paul, whereas they carry with them that proper and most manifest meaning in which they were understood by the Fathers,-it is indeed a crime the most unworthy that they should be wrested, by certain contentions and wicked men, to fictitious and imaginary tropes, whereby the verity of the flesh and blood of Christ is denied, contrary to the universal sense of the Church, which, as the pillar and ground of truth, has detested, as satanical, these inventions devised by impious men; she recognising, with a mind ever grateful and unforgetting, this most excellent benefit of Christ.
CHAPTER VIII.
ON THE MOST HOLY SACRAMENT OF THE EUCHARIST
CANON I.-If any one denieth, that, in the sacrament of the most holy Eucharist, are contained truly, really, and substantially, the body and blood together with the soul and divinity of our Lord Jesus Christ, and consequently the whole Christ; but saith that He is only therein as in a sign, or in figure, or virtue; let him be anathema.
CANON lI.-If any one saith, that, in the sacred and holy sacrament of the Eucharist, the substance of the bread and wine remains conjointly with the body and blood of our Lord Jesus Christ, and denieth that wonderful and singular conversion of the whole substance of the bread into the Body, and of the whole substance of the wine into the Blood-the species Only of the bread and wine remaining-which conversion indeed the Catholic Church most aptly calls Transubstantiation; let him be anathema.
CANON III.-If any one denieth, that, in the venerable sacrament of the Eucharist, the whole Christ is contained under each species, and under every part of each species, when separated; let him be anathema.
CANON IV.-If any one saith, that, after the consecration is completed, the body and blood of our Lord Jesus Christ are not in the admirable sacrament of the Eucharist, but (are there) only during the use, whilst it is being taken, and not either before or after; and that, in the hosts, or consecrated particles, which are reserved or which remain after communion, the true Body of the Lord remaineth not; let him be anathema.
CANON V.-If any one saith, either that the principal fruit of the most holy Eucharist is the remission of sins, or, that other effects do not result therefrom; let him be anathema.
CANON VI.-If any one saith, that, in the holy sacrament of the Eucharist, Christ, the only-begotten Son of God, is not to be adored with the worship, even external of latria; and is, consequently, neither to be venerated with a special festive solemnity, nor to be solemnly borne about in processions, according to the laudable and universal rite and custom of holy church; or, is not to be proposed publicly to the people to be adored, and that the adorers thereof are idolators; let him be anathema.
CANON VII.-If any one saith, that it is not lawful for the sacred Eucharist to be reserved in the sacrarium, but that, immediately after consecration, it must necessarily be distributed amongst those present; or, that it is not lawful that it be carried with honour to the sick; let him be anathema.
CANON VIII.-lf any one saith, that Christ, given in the Eucharist, is eaten spiritually only, and not also sacramentally and really; let him be anathema.
CANON IX.-If any one denieth, that all and each of Christ's faithful of both sexes are bound, when they have attained to years of discretion, to communicate every year, at least at Easter, in accordance with the precept of holy Mother Church; let him be anathema.
CANON X.-If any one saith, that it is not lawful for the celebrating priest to communicate himself; let him be anathema.
CANON XI.-lf any one saith, that faith alone is a sufficient preparation for receiving the sacrament of the most holy Eucharist; let him be anathema. And for fear lest so great a sacrament may be received unworthily, and so unto death and condemnation, this holy Synod ordains and declares, that sacramental confession, when a confessor may be had, is of necessity to be made beforehand, by those whose conscience is burthened with mortal sin, how contrite even soever they may think themselves. But if any one shall presume to teach, preach, or obstinately to assert, or even in public disputation to defend the contrary, he shall be thereupon excommunicated.