is never anything but the basis for an entity whose Being has to take over Being-a-basis.
Dasein is its basis existently—that is, in such a manner that it understands itself in terms of possibilities, and, as so understanding itself, is that entity which has been thrown. But this implies that in having a potentiality-for-Being it always stands in one possibility or another: it constantly is not other possibilities, and it has waived these in its existentiell projection. Not only is the projection, as one that has been thrown, determined by the nullity of Being-a-basis; as projection it is itself essentially null. This does not mean that it has the ontical property of 'inconsequentiality' or 'worthlessness'; what we have here is rather something existentially constitutive for the structure of the Being of projection. The nullity we have in mind belongs to Dasein's Being-free for its existentiell possibilities. Freedom, however, is only in the choice of one possibility—that is, in tolerating one's not having chosen the others and one's not being able to choose them.
In the structure of thrownness, as in that of projection, there lies essentially a nullity. This nullity is the basis for the possibility of inauthentic Dasein in its falling; and as falling, every inauthentic Dasein factically is. Care itself, in its very essence, is permeated with nullity through and through. Thus "care"—Dasein's Being—means, as thrown projection, Being-the-basis of a nullity (and this Being-the-basis is itself null). This means that Dasein as such is guilty, if our formally existential definition of "guilt" as "Being-the-basis of a nullity" is indeed correct.
Existential nullity has by no means the character of a privation, where something is lacking in comparison with an ideal which has been set up but does not get attained in Dasein; rather, the Being of this entity is already null as projection; and it is null in advance of [vor] any of the things which it can project and which it mostly attains.1 This nullity, moreover, is thus not something which emerges in Dasein occasionally, attaching itself to it as an obscure quality which Dasein might eliminate if it made sufficient progress.
In spite of this, the ontological meaning of the notness [Nichtheit] of this existential nullity is still obscure. But this holds also for the ontological essence of the "not" in general . Ontology and logic, to be sure, have exacted a great deal from the "not", and have thus made its possibilities visible in a piecemeal fashion; but it itself has not been unveiled ontologically. Ontology came across the "not" and made use of it. But is it so obvious
1 The negative character to which Heidegger here calls attention is not brought out as clearly by the word 'projection' (etymologically, 'throwing forward') as it is by the German 'entwerfen' ('throwing off' or 'throwing away'), where the prefix 'ent-' indicates separation.