potentiality-for-Being, it is not yet. Only because the Being of the "there" receives its Constitution through understanding and through the character of understanding as projection, only because it is what it becomes (or alternatively, does not become), can it say to itself 'Become what you are', and say this with understanding.
[146] Projection always pertains to the full disclosedness of Being-in-the-world; as potentiality-for-Being, understanding has itself possibilities, which are sketched out beforehand within the range of what is essentially disclosable in it. Understanding can devote itself primarily to the disclosedness of the world; that is, Dasein can, proximally and for the most part, understand itself in terms of its world. Or else understanding throws itself primarily into the "for-the-sake-of-which"; that is, Dasein exists as itself. Understanding is either authentic, arising out of one's own Self as such, or inauthentic. The 'in-' of "inauthentic" does not mean that Dasein cuts itself off from its Self and understands 'only' the world. The world belongs to Being-one's-Self as Being-in-the-world. On the other hand, authentic understanding, no less than that which is inauthentic, can be either genuine or not genuine. As potentiality-for-Being, understanding is altogether permeated with possibility. When one is diverted into [Sichverlegen in] one of these basic possibilities of understanding, the other is not laid aside [legt ... nicht ab]. Because understanding, in every case, pertains rather to Dasein's full disclosedness as Being-in-the-world, this diversion of the understanding is an existential modification of projection as a whole. In understanding the world, Being-in is always understood along with it, while understanding of existence as such is always an understanding of the world.
As factical Dasein, any Dasein has already diverted its potentiality-for-Being into a possibility of understanding.
In its projective character, understanding goes to make up existentially what we call Dasein's "sight" [Sicht]. With the disclosedness of the "there", this sight is existentially [existenzial seiende]; and Dasein is this sight equiprimordially in each of those basic ways of its Being which we have already noted: as the circumspection [Umsicht] of concern, as the considerateness [Rucksicht] of solicitude, and as that sight which is directed upon Being as such [Sicht auf das Sein als solches], for the sake of which any Dasein is as it is. The sight which is related primarily and on the whole to existence we call "transparency" [Durchsichtigkeit]. We choose this term to designate 'knowledge of the Self'1 in a sense which is well understood,
1 '"Selbsterkenntnis"'. This should be carefully distinguished from the 'Sichkennen' discussed on H. 124-125. Perhaps this distinction can be expressed—though rather crudely—by pointing out that we are here concerned with a full and sophisticated knowledge of the Self in all its implications, while in the earlier passage we were concerned with the kind of 'self-knowledge' which one loses when one 'forgets oneself' or does something so out of character that one 'no longer knows oneself'.