Kenelm Digby on Quantity as Divisibility

Abstract

Abstract Kenelm Digby’s Two Treatises, of the Nature of Bodies and of the Nature of Mans Soule (1644) defends quite an idiosyncratic approach to mind-body dualism. In his use of the divisibility argument to prove that the human soul cannot be a material substance, Digby takes an uncompromising stand for merely potential material parts. In his Treatise of Bodies the present article focuses on the mode of construction of the definition of quantity as divisibility and on its links to two distinct fundamental arguments against the actual material parts doctrine. The first, positive, argument consists of a semantic reason drawn from Digby’s general doctrine of meaning, whereas the second, negative, argument, addresses the traditional question of the composition of the continuum. The latter, the author contends, does not build on the medieval controversy itself, but on Digby’s opposition to Galileo’s claim of indivisibilism in his Dialogues Concerning Two Sciences (1638).