Problems About Accidents

Aristotle does not deal with the non-substance categories in any detail. The Categories ends with some loosely related chapters on contrariety and other types of opposition, on priority and simultaneity, on motion and on having. In the Latin world, the Book of the Six Principles, formerly attributed to Gilbert of Poitiers (d. 1154), attempts to fill the gap left by Aristotle’s failure to give a detailed discussion of the six categories coming after Quality.

In the Arabic world, al-FarabI filled this gap by analyzing the remaining six categories in detail.

Regarding the individuation of accidents, Porphyry suggested that an individual accident such the fragrance of an apple can be separated from its subject, and thus can exist separately from what it was in, but only if it gets transferred to another subject. Porphyry’s view of individual accidents as dependent on individual substance, albeit in a transferable way, was taken up and transmitted to the Latin Middle Ages by Boethius.

Peter Abelard took a different view of individual accidents. He understood Aristotle to say that what is in a subject cannot subsequently exist separated from that subject. He held that individual accidents are not transferable between subjects, but at the same time, he held that they do not attach with necessity to their actual subjects: an individual accident inhering in a given subject might have inhered in a different subject.

The question whether individual accidents are individuated by the substances in which they inhere takes on an added significance when considered in relation to the Christian doctrine of the Eucharist. The Church’s teaching is that in the Eucharist the bread and wine become the body and blood of Christ. Berengar of Tours (d. 1088) argued that this doctrine entailed that if the bread changes substantially into the body of Christ while preserving the accidental features it had when it was bread (rather than merely preserving the appearance of those accidental features), then the same individual accidents must inhere first in one substance and then in another. Thus, it seems that the Church’s doctrine, when transposed into the language of the Categories, is not consistent with the theory that individual accidents are individuated by their substantial subjects and are not transferable from one substance to another.