  Heidegger's account of Dasein's relation towards the possibility of its own not-Being forms the backbone of a reinterpretation of the phenomenon of care—the “formally existential totality of Dasein's ontological structural whole” (Being and Time 41: 237). Care is now interpreted in terms of Being-towards-death, meaning that Dasein has an internal relation to the nothing (i.e., to not-being; see Vallega-Neu 2003, 21, for an analysis that links this ‘not’ quality to the point made earlier that sets of unactualized possibilities of Being are structural components of Dasein's Being). As one might expect, Heidegger argues that Being-towards-death not only has the three-dimensional character of care, but is realized in authentic and inauthentic modes. Let's begin with the authentic mode. We can think of the aforementioned individualizing effect of Dasein's awareness of the possibility of its own not-Being (an awareness that illuminates its own being-able-to-Be) as an event in which Dasein projects onto a possible way to be, in the technical sense of such possibilities introduced earlier in Being and Time. It is thus an event in which Dasein projects onto a for-the-sake-of-which, a possible way to be. More particularly, given the authentic character of the phenomenon, it is an event in which Dasein projects onto a for-the-sake-of-itself. Heidegger now coins the term anticipation to express the form of projection in which one looks forward to a possible way to be. Given the analysis of death as a possibility, the authentic form of projection in the case of death is anticipation. Indeed Heidegger often uses the term anticipation in a narrow way, simply to mean being aware of death as a possibility. But death is disclosed authentically not only in projection (the first dimension of care) but also in thrownness (the second dimension). The key phenomenon here is the mode of disposedness that Heidegger calls anxiety. Anxiety, at least in the form in which Heidegger is interested, is not directed towards some specific object, but rather opens up the world to me in a certain distinctive way. When I am anxious I am no longer at home in the world. I fail to find the world intelligible. Thus there is an ontological sense (one to do with intelligibility) in which I am not in the world, and the possibility of a world without me (the possibility of my not-Being-in-the-world) is revealed to me. “[The] state-of-mind [mode of disposedness] which can hold open the utter and constant threat to itself arising from Dasein's ownmost individualized Being, is anxiety. In this state-of-mind, Dasein finds itself face to face with the ‘nothing’ of the possible impossibility of its existence” (Being and Time 53: 310). Heidegger has now reinterpreted two of the three dimensions of care, in the light of Dasein's essential finitude. But now what about the third dimension, identified previously as fallen-ness? Since we are presently considering a mode of authentic, i.e., not fallen, Dasein, it seems that fallen-ness cannot be a feature of this realization of care, and indeed that a general reformulation of the care structure is called for in order to allow for authentic Being. This is an issue that will be addressed in the next section. First, though, the inauthentic form of Being-towards-death needs to be brought into view.