Siger of Brabant and Thomas Aquinas on Divine Power and the Separability of Accidents
Abstract
I wish to examine an excerpt from Siger of Brabant's Questions on the Book of Causes that has already received considerable attention on the part of scholars. 1 The text is remarkable for its criticism of Aquinas's doctrine that God can conserve an accident independently from the substance in which it naturally inheres, as he does in the case of the Eucharist. While Siger is careful not to question the validity and indeed the absolute certainty of the Eucharist as a theological truth, he is critical about the claim that God's being able to make accidents subsist independently from substance can be demonstrated or shown to be true by relying solely on the use of natural reason: 'Some people argue fallaciously believing that they can show and demonstrate by natural reason that the first cause can make it (come to pass) that the accident can exist without the subject of that accident.' 2 To understand Siger's scepticism on this issue we must turn to his Questions on Aristotle's Metaphysics , where he lists six differences between theology and philosophy, only the first four of which need concern us here. The first difference concerns the methodologies, or 'modes of