This paper wishes to make a contribution to the study of how seventeenth-century scholasticism adapted to the new intellectual challenges presented by the Reformation. I focus in particular on the theory of accidents, which Reformed scholastic philosophers explored in search of a philosophical understanding of the rejection of the Catholic and Lutheran interpretations of the Eucharist. I argue that the Calvinist scholastics chose the view that actual inherence is part of the essence of accidents because it was coherent with their (...) theology. In this paper, I bring to attention the Reformed scholastic philosophy which was taught in the Scottish universities in the first half of the seventeenth century, an area so far neglected by scholars. In so doing, I compare Scottish scholasticism with coeval Calvinist sources, and highlight the differences from authoritative Catholic and Lutheran philosophers. The conclusion is that Calvinist scholasticism, both Scottish and Continental, brought about fundamental changes in seventeenth-century metaphysics, which are coherent with a humanist interpretation of Aristotle, and anticipate some themes of early modern philosophy. (shrink)