Aquinas and Real Presence: Understanding Transubstantiation

When Augustine says, you will not be eating this body which you see, he does not intend to exclude the reality of Christ's body; what he does rule out is that they would eat it under the same form in which they were looking at it. When he adds, I have entrusted a mystery to you. If you take it in a spiritual way it will bring you life, he does not mean that the body of Christ is in this sacrament only as in a mystical symbol; it is said to be there spiritually, that is, invisibly and by the power of the spirit. For this reason, commenting on the text of John, 'the flesh is of no avail',19 he writes, it is of no avail, in the way they understood. They thought eating flesh as if it had been torn from the carcass or sold in the butcher’s stall; they did not understand flesh as enlivened by the spirit. When the spirit s united to the flesh, then indeed it is of great avail, for if flesh could never be of avail, the Word would not have been made flesh to dwell among us.20 57 59

3. The body of Christ is not in this sacrament in the way a body is in place. The dimensions of a body in place correspond with the dimensions of the place that contains it. Christ's body is here in a special way that is proper to this sacrament. For this reason we say that the body of Christ is on different altars, not as in different places, but as in the sacrament. In saying this we do not mean that Christ is only symbolically there, although it is true that every sacrament is a sign, but we understand that Christ's body is there, as we have said, m a way that is proper to this sacrament. 59

4. This objection considers the presence of Christ's body as if it were present in the way that is natural for a body to be present, that is visibly in its normal appearance; it does not envisage spiritual, non-visible presence, in the way of a spirit and by the power of the Spirit. For this reason Augustine says, if you have understood in a spiritual way the words of Christ about his flesh, they are spirit and life for you, if you have understood them in a carnal manner, they are still spirit and life, but not for you.2 59

NOTE: This article is a first step in the theology of transubstantiation. The doctrine of impanation holds that the substance of the bread is hypostatically united to Christ, the doctrine of companation holds that the substance of the bread is united in some unspecified way to the body of Christ; the Catholic dogma defined at the Council of Trent teaches that the substance of the bread does not remain but is changed into the body of Christ—transubstantiation.

Some have held that after the consecration the substance of the bread and wine remains in this sacrament. But this position cannot be sustained. First of all, it would destroy the reality of this sacrament which demands that the very body of Christ exist in it. Now, his body is not there before the consecration. But a thing cannot be where it was not before except by being brought in locally or by something already there being changed into it. For example, a fire is started in a household because either it is brought into it from outside or is newly kindled there. Now it is clear that the body of Christ does not begin to exist in this sacrament by being brought in locally. First, because it would thereby cease to be in heaven, since anything that is locally moved begins to be somewhere only by leaving where it was. Second, every bodily thing that is moved from place to place must pass through all the intermediate places, and there is no question of that in the present case. Third, it is impossible that the one movement of a bodily thing that is being locally moved should end up at the same time in different places; now the body of Christ in this sacrament begins simultaneously to be in different places. For these reasons it remains that there is no other way in which the body of Christ can begin to be in this sacrament except through the substance of the bread being changed into it. Now, what is changed into something else is no longer there after the change. The reality of Christ's body in this sacrament demands, then, that the substance of the bread be no longer there after the consecration.