way to approach angst is to ask why Heidegger analyzes it. Heidegger says that the analysis of angst plays a methodological role (SZ181, 182, 184, 185, 190). Since he analyzes this mood only as much as he needs to in order to achieve his broader goal, Heidegger does not have a completely worked out phenomenology of it. This is why it is not obvious which mood he is talking about. Our best approach is to identify the methodological role of angst.
Typically, angst is taken to deserve its place in SZ by virtue of its connection to authenticity or ownedness. Angst is the mood that brings us to our authentic being, and an authentic existence is one that either experiences angst or is ready for such an experience. Angst thus belongs to the story told in Division II of SZ about anticipatory resoluteness, alongside the accounts of the call of conscience and being-towards-death. Yet Heidegger analyzes angst in Division I. Why? The peculiar location of the analysis of angst is rarely acknowledged; it is often denied or dismissed.1 The analysis of angst comes hard on the heels of Heidegger’s account of falling; it allows him to transition from the analysis of Dasein’s everydayness to the characterization of the unity of Dasein’s being. It is needed for this transition because the analysis of angst solves a very particular problem.2
The problem that the analysis of angst is supposed to solve is that it belongs to everydayness that we fail to see our own being. This failure to grasp our being is falling. Falling is our being amidst (bei) entities or our openness to them (SZ175). (Elsewhere, Heidegger uses ‘falling’ differently, to name unowned or inauthentic being amidst entities. I leave this unowned falling aside for the moment.) Despite the term’s theological heritage, ‘falling’ (Verfallen) names not a fall from grace but something like an ontological ‘motion’ (SZ180). Talk of motion metaphorically grasps the dative structure of our openness to being or meaning. Such openness is distinctive of Dasein, and it is always an openness to entities, in their being. This to which can be grasped as a motion: openness is pulled or drawn out towards ...; ‘falling’ captures this opening out. Extending the metaphor, opening out can be expressed as a motion from ...
1 Dreyfus, for instance, imaginatively moves the analysis of angst out of Division I, reserving discussion of it for his treatment of Division II. Hubert L. Dreyfus, Being-in-the-World: A Commentary on Heidegger’s Being and Time, Division I (Cambridge, MA: The MIT Press, 1991). He acknowledges that angst plays a methodological role in SZ (176) but does not explore it, citing a confusion in the notion of falling (226).
2 For a more detailed analysis of the methodological role of angst in SZ, see Katherine Withy, “The Methodological Role of Angst in Being and Time,” Journal of the British Society for Phenomenology 43:2 (2012): 195–211.