Dasein fundamentally concerns the relation between being and time at a pre-predicative level of worldly-engagement, a level prior to articulated judgment, prior to the conscious conceptualizations of traditional metaphysics or Husserlian phenomenology; hence, the title of Heidegger’s famous work, Being and Time (Richardson 1967). In Heidegger’s terms, an “authentic” understanding of the being concerned about its being rests upon a proper understanding of that being’s temporality.
This union of past, present and future as modes of originary-time in Dasein’s being-in-the-world renders Dasein authentic—one with itself or its own—because the projection into the future makes the present and the past part of Dasein’s project—its essence is its existence. However, insofar as I assume a project or life-orientation passively and without realizing myself as responsible for that project, argues Heidegger, I live inauthentically. And this is because I am engaged in the world without a full understanding of myself within the world. Put differently, rather than consciously make myself who I am through my choices, I passively assume a role within society—hence the temptation to label Heidegger an existentialist, a label the he himself rejected.
Like Husserl’s notion of the living-present, Heidegger’s theory of Dasein’s structure as originary temporality considers Dasein a mode of objectivating not itself objectified, the condition for the possibility of all awareness of objects at the levels of worldly- and ordinary-time (BT § 70).
Heidegger quite unequivocally privileges the moment of the future in his account of Dasein’s originary temporality. By emphasizing Dasein’s being-in-the-world as manifest through its throwness in the world, and its care for the world as manifest through its projects, Heidegger’s focuses on Dasein’s futural character distinguishes his account from Husserl’s, for Husserl emphasized the moment of retention in the living-present almost to the exclusion of any remarks on protention, the anticipatory moment of the living-present. For these reasons, Heidegger considered his phenomenology radically different from Husserl’s. In particular, Heidegger thought Husserl’s overly cognitive account of how consciousness constitutes a unified temporal object across a succession of moments articulated only one of the many issues surrounding the temporality of Dasein, a merely scientific or cognitive account of how consciousness presents an object in the world to itself. Husserl’s restrictive phenomenology of time, Heidegger argues, overlooks the existential dimension of Dasein’s temporality, how Dasein reckons with the world at a tacit level rather than how it cognizes the world. And in particular, Heidegger thought philosophy could assess Dasein’s manner of reckoning with the world only by examining its futural moment as manifest in the projects that characterize Dasein’s mode of existence as the ongoing realization of its possibilities or construction of its essence.