Abstract

Although scholars acknowledged that Avicenna’s science of the soul stands at the crossroads between natural philosophy and metaphysics, thus combining an overall physical investigation of all sublunary souls with a trans-physical (or proto-metaphysical) inquiry into the human rational soul, this paper aims to show a further disciplinary entanglement within Avicenna’s science of the soul, which features in the aforementioned physical investigation and helps to frame it, that is, the interaction between natural philosophy and medicine. Despite the strict division between these two disciplines in Avicenna’s system of science, medicine seems to decisively contribute to accounting for the bodily functions of living beings. For this reason, Avicenna refers to medicine several times in his exposition on the soul. This paper approaches the disciplinary entanglement between natural philosophy and medicine in psychology by focusing on the medical concept of pneuma (rūḥ), which prominently features in the exposition of three main issues in psychology, i.e., body ensoulment, powers differentiation, and emotions.