In this paper we focuse on how the first Heidegger changed the essential idea of phenomenology: if the terms of intentionality, pure consciousness, transcendental subject, noema and noesis radically disappear from Heidegger’s conceptuality, what does it mean exactly? Does Heidegger preserve anything from the idea of intentionality, from Husserl’s task of clarifying the aprioristic correlation between consciousness and object, and from Husserl’s relation of foundation of intentional modalities of higher level on modalities of lower level? We want here to emphasize some essential changes concerning the idea of phenomenology: the holistic structure of experience, the task of clarifying the structure of transcendance as a foundation of intentionality, and the inversion of Husserl’s relation of foundation. On the contrary, we show how Husserl’s concept of sense is essentially different from that of ideal signification.
