On (priest + words + material + intention) being the sum total of all causes in the consecration of the Eucharist in Catholic sacramental theology, Christiaan Kappes noted that
Herein
lies a potential inconsistency in applying Aristotelian causality. Real causes
touch or act upon matter immediately (changing it) as with efficient causes.
Therefore, in what sense is the priest called an instrumental cause? In virtue
of an intrinsic power, he causes some effect by his operation of saying the
words. Each power and operation is from him as a subject. If God is efficient
cause, while the priest is an inferior instrument, yet two causes create a new
substance or eliminate an old one, it is not clear in what sense the flesh,
soul, or priestly character eliminate the bread-form, introduce or displace
Christ from heaven into accidental-bread-form, or (arguably) annihilate
bread-matter. (Christiaan Kappes, The Epiclesis Debate at the Council of
Florence [Notre Dame, Ind.: University of Notre Dame Press, 2019], 341 n.
19)
