Abstract
MEDIEVAL PHILOSOPHERS HAD NO SINGLE RESPONSE to the difficult question of how souls are related to the bodies they animate. In this respect, the theory of psychological inherence advanced by the noted Parisian philosopher John Buridan is a case in point. Buridan offers different accounts of the soul-body relation, depending upon which of two main varieties of natural, animate substance he is explaining. In the case of human beings, he defends a version of immanent dualism: the thesis that the soul is an immaterial, everlasting, and created entity, actually inhering in each and every body it animates, and thus numerically many. But when his explanandum is the relation between nonhuman animal or plant souls and their bodies, Buridan is a materialist; that is, he regards the sensitive and vegetative souls of such creatures as no more than collections of material, extended powers exhaustively defined by their biological functions, and hence as corruptible as the particular arrangements of matter they happen to animate.