Russell, les « sense-data » et les objets physiques : une approche géométrique de la notion de classification

Abstract

This article aims at setting up a link between Russell’s work on the foundations of geometry and his notorious articles on perception, matter and sense-data published between 1910 and 1914. We firstly stress the fact that a russellian sense-datum is not a mental event: in The Problems of Philosophy, sense-data are as external to the mind as any physical thing. We next analyze the 1912 unpublished paper On Matter in which Russell, for the first time, attributes two positions, instead of one, to a sense-datum: a place from which it is seen and a place where it is seen. This theoretical change allows Russell to regard the sense-datum as a neutral point of intersection of two differents classes: a series of physical events and a series of mental perspectives. The very idea that a same thing can be sorted according to different categories, and thus that the aristotelian mode of classification in genus and species is not the only possible one, is both the keystone of the 1914 theory of the relations between sense-data and physical things and the kernel of the subsequent rallying to « neutral monism ». We claim, in a third section, that this idea is itself an echo of the way Russell defines the projective geometry as a general theory of incidence relations in The Principes of Mathematics (1903).