Image: “The Triumph of St. Thomas Aquinas” (AD 1471) by Benozzo Gozzoli, with Aristotle on the left and Plato on the right. Musée du Louvre.
This is the third and final installment in a three-part series on the doctrine of Transubstantiation in the sacramental theology of Thomas Aquinas.
The question remains whether these particular categories, substance and accidents, are aiding or hindering our understanding of the doctrine of the Eucharist. But first, let us review some praiseworthy features of the Thomist account.
We can commend the extent to which these distinctions remove any crude understanding of the Real Presence. As we have seen, it is precisely because Thomas makes a clear distinction between substance and accident that he is able to guard against any vulgar understanding of an actual eating of blood and flesh, which appears to be, given the polemics of the time period, what many Protestants supposed that Rome taught (and perhaps not a few Catholics themselves). The numerous miracles of the host turning into actual flesh and the wine turning into actual blood, which are often then venerated in shrines, have only reinforced this crude understanding of Transubstantiation. Yet for Thomas at least, the compositional make-up of the bread, at the level of physical properties (species), remains as before. Thus, even though its ontological status has changed, what is being consumed is still, at the chemical level, bread. (By the way, the most significant criticism of the Mass by Protestants was, and remains, the Catholic belief in the Mass as a recurring sacrifice.)
Moreover, we can commend the extent to which Thomas repeatedly affirms the bodily presence of Christ in heaven, as distinct from his sacramental presence on earth. The corporal integrity of Christ’s ascended and glorified existence is important for a Reformed understanding of Christ’s high priesthood. If the body of the ascended Christ is given the divine properties of omnipresence, which may be the Lutheran position, then we would no longer have a glorified human body but something altogether different – a tertium quid that is a commingling of human and divine properties. Thomas rejects any such implications in his rejection of local and movable presence. For Thomas, the body of Christ in heaven remains and is at rest, not extended or moved into our space and time.
Yet, even with these commendations in mind, the Protestant is still faced with whether “substance” is a proper category for understanding the presence of Christ in the Eucharist. In regards to the bodily presence, the existence of a “substance” that is distinct from its physical “accidents” is necessary for underwriting Thomas’ whole conception of a real presence that is in “very truth” real (not merely a symbol) and yet not local. However, it is highly debatable whether any particular thing has a substance that, in some way, transcends the physical properties we perceive by our senses. Without the accidents, at least some of them, what can be predicated of substance?
Also, what gain is achieved by positing such a substance? In particular, is it even possible to conceive of a substance without conceiving of at least some of its accidents? Indeed, such accidents are necessary for the “what-ness” (substance) of a thing to be articulated with any comprehension. Therefore, can there be a clear separation of substance and accident?
In other words, in any meaningful description of substance (of body, blood, etc.), it seems to be necessary to include certain accidents; otherwise, we have a concept without content. While some accidents can be described as “non-essential,” such as the color of one’s skin, the skin itself surely requires some accidents to make it skin and not, say, a plastic bottle. Skin is a composite of accidents (all that is observable by the senses), some of which are required to make it skin. Without these “essential” accidents, we do not have skin. Likewise with body or blood, all that is available to our sense perception will include certain essential attributes that make the body a body and the blood to be blood. In the Thomist formulation of the Eucharistic elements, we have the substance of Christ’s body in the accidents of bread; yet, what is the content of this substance of Christ’s body? There is no content. It is completely void, once all “accidental” predicates are removed. This may be a limitation of our modern understanding, given that a substance (that which makes a thing what it is) is invariably understood according to its physical composition, at least in part. Terence Nichols, professor of theology at the University of St. Thomas, explains the problem:
But it would seem that what makes bread bread and wine wine are the chemical and molecular structures of their elements (flour, water, alcohol, etc.). But these are not changed in transubstantiation. “Substance” therefore must mean something else, some ghostly reality behind the chemical structures of bread and wine. But it is very hard for modern hearers to grasp what this occult “substance” might be, or how it makes the bread what it is and the wine what it is.
Given that a Thomist-Aristotelian understanding of substance is especially difficult to comprehend today (if ever!), the problem is now whether the formulation of Trent is irrevocably bound to these philosophical categories. The Tridentine decrees follow Thomas in its formulation of Transubstantiation. Edward Schillebeeckx affirms that, indeed, the bishops at Trent were authorizing Aristotelian categories of substance and accident. According to Schillebeeckx, even though they preferred to use “species” instead of “accidents,” the conciliar records indicate that they understood the two terms to mean the same thing. Trent is thereby not philosophy-neutral in its formulation of the Real Presence. As Schillebeeckx writes, “The fathers of the Council of Trent were not trying to dissociate themselves from the word ‘accidents’ for the very good reason that, whether they were strict Thomists or Scotists or whatever they were, they were all in their own way Aristotelian scholastics in their manner of thinking….”
Thus, a significant question today is how the Roman Catholic understanding of Real Presence can be formulated in different categories that may complement, not replace, the substance ontology that has received conciliar sanction. And perhaps such an alternate formulation may approach nearer to the Reformed understanding. After all, both Thomas and the Reformed tradition affirm a “sacramental presence” without analogy in nature and without local presence, for Christ remains in his glorified body at the right hand of the Father.
 See the Real Presence Eucharistic Education and Adoration Association: http://www.therealpresence.org/eucharst/mir/a3.html.
 Terence Nichols, “Transubstantiation and Eucharistic Presence,” Pro Ecclesia 11: 1 (2002): 59.
 The canons and decrees of the sacred and oecumenical Council of Trent, ed. and trans. J. Waterworth (London: Dolman, 1848), 78.
 Edward Schillebeeckx, The Eucharist (London: Burns & Oats, 2005 ), 55. Terence Nichols disagrees with Schillebeeckx on this point. See “Transubstantiation and Eucharistic Presence,” 62.