What is the science of the soul ? A case study in the evolution of late medieval natural philosophy

Abstract

This paper aims at a partial rehabilitation of E. A. Moody's characterization of the 14th century as an age of rising empiricism, specifically by contrasting the conception of the natural science of psychology found in the writings of a prominent 13th-century philosopher (Thomas Aquinas) with those of two 14th-century philosophers (John Buridan and Nicole Oresme). What emerges is that if the meaning of empiricism can be disengaged from modern and contemporary paradigms, and understood more broadly in terms of a cluster of epistemic doctrines concerned with the methodology of knowing, it characterizes very appropriately some of the differences between the ways in which late-medieval thinkers both understood and practised the science of psychology. In particular, whereas Aquinas thinks psychology is about reasoning demonstratively to the real nature of the soul from its evident operations (thereby assimilating psychology to metaphysics), Buridan and Oresme, both of whom doubt whether real animate natures can be known empirically, focus on giving detailed accounts of those operations themselves (thereby assimilating psychology to physics).