We have already intimated that Dasein has a pre-ontological Being as its ontically constitutive state. Dasein is in such a way as to be something which understands something like Being.1 Keeping this interconnection firmly in mind, we shall show that 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 as the horizon for the understanding of Being, and in terms of temporality as the Being of Dasein, which understands Being . This task as a whole requires that the conception of time thus obtained shall be distinguished from the way in which it is ordinarily understood. This ordinary way of understanding it has become explicit in an interpretation [18] precipitated in the traditional concept of time, which has persisted from Aristotle to Bergson and even later. Here we must make clear that this conception of time and, in general, the ordinary way of understanding it, have sprung from temporality, and we must show how this has come about. We shall thereby restore (o the ordinary conception the autonomy which is its rightful due, as against Bergson's thesis that the time one has in mind in this conception is space.
'Time' has long functioned as an ontological—or rather an ontical—criterion for naively discriminating various realms of entities. A distinction has been made between 'temporal' entities (natural processes and historical happenings) and 'non-temporal' entities (spatial and numerical relationships). We are accustomed to contrasting the 'timeless' meaning of propositions with the 'temporal' course of propositional assertions. It is also held that there is a 'cleavage' between 'temporal' entities and the 'supra-temporal' eternal, and efforts are made to bridge this over. Here 'temporal' always means simply being [seiend] 'in time'—a designation which, admittedly, is still pretty obscure. The Fact remains that time, in the sense of 'being [sein] in time', functions as a criterion for distinguishing realms of Being. Hitherto no one has asked or troubled to investigate how time has come to have this distinctive ontological function, or with what right anything like time functions as such a criterion; nor has anyone asked whether the authentic ontological relevance which is possible for it, gets expressed when "time" is used in so naively ontological a manner. 'Time' has acquired this 'self-evident' ontological function · 'of its own accord', so to speak; indeed it has done so within the horizon of the way it is ordinarily understood. And it has maintained itself in this function to this day.
1 'Dasein ist in der Weise, seiend so etwas wie Sein zu verstehen.'