Thomism, Grounding and <i>Per Se</i> Causal Series*

Abstract In recent years the notion of grounding has been extensively discussed within metaphysics, whilst there has also been a revival of interest within Thomistic thought. In this paper I want to explore the connections between one aspect of Thomistic metaphysics, namely its account of per se or essentially ordered causal chains, and grounding. The aim of the paper is to suggest that the two are very closely connected, and that contemporary metaphysicians would do well to attend to medieval debates in further thinking about grounding. In order to do this the paper first outlines a dominant view of per se causal chains and then goes on to explicate an influential notion of grounding. After this it draws out the similarities and differences between per se causal chains and grounding, and concludes with some thoughts as to how they might be related.