'problem of knowledge' has often been ontologically disguised to the point where it has been lost sight of altogether.
The entity which is essentially constituted by Being-in-the-world is itself in every case its 'there'. According to the familiar signification of the word, the 'there' points to a 'here' and a 'yonder'. There 'here' of an 'I-here' is always understood in relation to a 'yonder' ready-to-hand, in the sense of a Being towards this 'yonder'—a Being which is de-severant, directional, and concernful. Dasein's existential spatiality, which thus determines its 'location', is itself grounded in Being-in-the-world. The "yonder" belongs definitely to something encountered within-the-world. 'Here' and 'yonder' are possible only in a 'there'—that is to say, only if there is an entity which has made a disclosure of spatiality as the Being of the 'there'. This entity carries in its ownmost Being the character of not being closed off. In the expression 'there' we have in view this essential disclosedness. By reason of this disclosedness, this entity (Dasein), together with the Being-there1 of the world, is 'there' for itself.
When we talk in an ontically figurative way of the lumen naturale in  man, we have in mind nothing other than the existential-ontological structure of this entity, that it is in such a way as to be its "there". To say that it is 'illuminated' ["erleuchtet"] means that as Being-in-the-world it is cleared [gelichtet] in itself, not through any other entity, but in such a way that it is itself the clearing.2 Only for an entity which is existentially cleared in this way does that which is present-at-hand become accessible in the light or hidden in the dark. By its very nature, Dasein brings its "there" along with it. If it lacks its "there", it is not factically the entity which is essentially Dasein; indeed, it is not this entity at all. Dasein is its disclosedness.
We are to set forth the Constitution of this Being. But in so far as the essence of this entity is existence, the existential proposition, 'Dasein is its disclosedness', means at the same time that the Being which is an issue for this entity in its very Being is to be its 'there'. In addition to characterizing the primary Constitution of the Being of disclosedness, we will require, in conformity with the course of the analysis, an Interpretation of the kind of Being in which this entity is its "there" in an everyday manner.
This chapter, in which we shall undertake the explication of Being-in as such (that is to say, of the Being of the "there"), breaks up into two parts: A. the existential Constitution of the "there"; B. the everyday Being of the "there", and the falling of Dasein.
In understanding and state-of-mind, we shall see the two constitutive ways
1 'Da-sein'. See our note 1, p. 27, H. 7 above.
2 'Lichtung'. This word is customarily used to stand for a 'clearing' in the woods, not for a 'clarification'; the verb 'lichten' is similarly used. The force of this passage lies in the fact that these words are cognates of the noun 'Licht' ('light') .