Stumpf’s doctrine of the categories is of great importance for our understanding of his philosophy. This theme had been widely discussed among German thinkers after Kant; Brentano himself had repeatedly dealt with it since his early works. However, Stumpf considerably diverges from Brentano on this crucial philosophical topic. Although a systematic discussion can be found only in Stumpf’s posthumous Erkenntnislehre, his core ideas on the categories can be traced to his early work on space of 1873. In fact, Stumpf claims that the peculiar relationship between extension and color is analogous to the relationship that holds between substance and accidents. Thus, like any other category, substance empirically stems from perception. Sensory experience, for Stumpf, is made up of perceptual wholes, whose attributes are typically bound to each other, rather than separately given in bundles, as Hume and other associationists used to assume. Thus, the achievements of Stumpf’s (and others’) holist psychology effectively contributes a solution to this classic metaphysical problem.
