La neige est blanche ssi... Prédication et perception

摘要

The paper tackles the problem of the links between the formal (logical) syntax and semantics of perceptive judgements and their perceptive (geometrica) content. In the most elementary situations, the perceptive content is reducible to a qualitative filling-in of spatial domains (objects' extensions) by sensible qualities (colors, textures, etc.). These filling-in are describable by sections of suitable fibrations, which are particular cases of sheaves. The problem is therefore to understand how a logical syntax can be semantically interpreted in terms of section of sheaves. This is possible in the framework of topos theory.