II.v The Ontological Analytic of Dasein as Laying Bare the Horizon for an Interpretation of the Meaning of Being in General

Heidegger emphasizes that the 'interpretation' of Dasein must be our first requirement in the question of Being. (the interpretation of Dasein remains a problem of access - we have 'no right to resort to dogmatic constructions and apply just any idea of Being and actuality to this entity, no matter how 'self-evident' that idea may be; nor may any of the 'categories' which such an idea prescribes be forced upon Dasein without proper ontological consideration. We must rather choose such a way of access and such a kind of interpretation that this entity can show itself in itself and from itself [an ihm selbst von ihm selbst her]. And this means that it is to be shown as it is 'proximally and for the most part-in its average everydayness.'

everydayness is a provisional preparation for the antrhopological investigation...it is by no means a total or 'essential' character of Being.

This leads Heidegger to look at temporality (Zeitlichkeit):

whenever Dasein tacitly understands and interprets something like Being, it does
so with time as its standpoint. Time must be brought to light-and genuinely conceived-as the horizon for all understanding of Being and for any way of interpreting it. In order for us to discern this, time needs to be explicated primordially (original) as the horizon for the understanding of Being, and in terms of temporality as the being of Dasein, which understand Being.

Understanding Dasein must be limited temporally

...the central problematic of all ontology is rooted in the phenomenon of time, if rightly seen and rightly explained, and we must show how this is is the case.

...TEMPORAL DETERMINATENESS. Thus the fundamental ontological task of Interpreting Being as such includes working out the Temporality of Being.

Because Being cannot be grasped except by taking time into consideration, the answer to the question of Being cannot lie in any proposition that is blind and isolated.