Magali Roques

The aim of this project is to investigate the conception of grounding in fourteenth-century medieval philosophy, with a special emphasis on the realist Duns Scotus (1266-1308) and his nominalist opponent William of Ockham (1285-1345). Many philosophers take "grounding" to refer to a distinctive kind of metaphysical explanation. Indeed, grounding typically expresses a relation of priority and dependence between things. In this sense, grounding links metaphysics to explanation and is a core notion in the metaphysics of fundamentality, i.e. the research domain which investigates how some phenomena are built from more fundamental phenomena.

Until recently the generally held view has been that sustained discussion of grounding is, with a few exceptions such as Bolzano and Husserl, a recent phenomenon. However, it has sometimes been argued that philosophical reflection on grounding goes back to antiquity. The recent renewal of Aristotelianism in metaphysics has given rise to a renewed interest in scholastic views on the metaphysics of fundamentality, but the conceptions of grounding in the Aristotelian tradition of the Middle Ages are widely unknown. The main aim of this project is to fill this gap in our knowledge of the history of the notion of grounding.

Until now, scholars have identified the medieval counterpart to grounding as the relation that holds between substance and accident. I aim at correcting this identification by arguing that Scotus and Ockham appealed to a kind of non-causal dependence that corresponds to the contemporary notion of grounding in order to explain the idea of logical validity, the relation between the Persons of the Trinity and their properties, the hypostatic union, and the truthmakers of modal truths.

Apart from its exegetical and historical objective, the project also has a philosophical goal. It aims to bring together two debates that are currently more or less kept apart, namely the current debate on metaphysical explanation and the old but ongoing debate on explanation in philosophy of science. Because of an emphasis put on physics, philosophy of science tends to centre on causal explanation, while marginalizing notions of non-causal explanation. However, mathematical explanations are non-causal. And if non-causal mathematical explanations are no less legitimate than causal explanations in natural science, what justifies there being these two distinct kinds of explanation? The medieval concept of scientific explanation can be used in order to show that causal and non-causal explanations have a common root and are thus specific kinds of a unified genus of explanation.