International audienceThe theory of Mathematical Working Spaces (ThMWS) is a young theory that appeared in the field of didactics of mathematics a decade ago with the objective of describing and constructing the mathematical work of students in a school context. To this end, the theoretical framework aims to link and closely combine epistemological and cognitive approaches. In this article, we deepen the very notion of mathematical work by focusing first on an epistemological approach that specifies the nature of work in mathematics and then on a philosophical approach that connects work and communication in a dialectical relation. These two approaches highlight the more or less implicit ideological assumptions that guide our research in di...