Transubstantiation Through the Lens of Spacetime Substantivalism

The doctrine of transubstantiation (as understood by Aquinas and much subsequent Roman Catholic theology) involves the counter-intuitive claim that accidents can come to exist independently of any substance. In particular, the spatial dimensions of bread and wine can come to exist independently. I point out that a key idea that motivated this claim was an aspect of mediaeval philosophy of nature: namely, relationism about space. I argue that if relationism is dropped in favour of substantivalism, then room is made for a model of transubstantiation which needn't involve an implausible commitment to independently existing accidents.