Interpret this phenomenon according to the principles of its existential-ontological Constitution and function. The reasons for this lie partly in the general neglect of the existential analytic of Dasein, but more particularly in a failure to recognize the phenomenon of state-of-mindiv. Yet the factical rarity of anxiety as a phenomenon cannot deprive it of its fitness to take over a methodological function in principle for the existential analytic. On the contrary, the rarity of the phenomenon is an index that Dasein, which for the most part remains concealed from itself in its authenticity because of the way in which things have been publicly interpreted by the "they", becomes disclosable in a primordial sense in this basic state-of-mind.
Of course it is essential to every state-of-mind that in each case Being-in-the-world should be fully disclosed in all those items which are constitutive for it—world, Being-in, Self. But in anxiety there lies the possibility of a disclosure which is quite distinctive; for anxiety individualizes.  This individualization brings Dasein back from its falling, and makes manifest to it that authenticity and inauthenticity are possibilities of its Being. These basic possibilities of Dasein (and Dasein is in each case mine) show themselves in anxiety as they are in themselves—undisguised by entities within-the-world, to which, proximally and for the most part, Dasein clings.
How far has this existential Interpretation of anxiety arrived at a phenomenal basis for answering the guiding question of the Being of the totality of Dasein's structural whole?
¶ 41. Dasein's Being as Care
Since our aim is to grasp the totality of this structural whole ontologically, we must first ask whether the phenomenon of anxiety and that which is disclosed in it, can give us the whole of Dasein in a way which is phenomenally equiprimordial, and whether they can do so in such a manner that if we look searchingly at this totality, our view of it will be filled in by what has thus been given us. The entire stock of what lies therein may be counted up formally and recorded: anxiousness as a state-of-mind is a way of Being-in-the-world; that in the face of which we have anxiety is thrown Being-in-the-world; that which we have anxiety about is our potentiality-for-Being-in-the-world. Thus the entire phenomenon of anxiety shows Dasein as factically existing Being-in-the-world, The fundamental ontological characteristics of this entity are existentiality, facticity, and Being-fallen. These existential characteristics are not pieces belonging to something composite, one of which might sometimes be missing; but there is woven together in them a primordial context which makes up