This article explores a previously neglected manuscript essay in which Thomas White offers an account of the metaphysics underpinning transubstantiation. White’s views are of particular interest because his explanation employs a broadly mechanist framework, rather than the hylomorphism traditionally associated with Roman Catholic discussions of the Eucharist. The manuscript helps to shed light on a number of topics of importance to early modern philosophy including the reception of Descartes’ views, the relationship between theology and natural philosophy, and mechanist accounts of (...) identity and individuation. (shrink)