deprives the "today" of its character as present,1 and weans one from the conventionalities of the "they". When, however, one's existence is inauthentically historical, it is loaded down with the legacy of a 'past' which has become unrecognizable, and it seeks the modem. But when historicality is authentic, it understands history as the 'recurrence' of the [392] possible, and knows that a possibility will recur only if existence is open for it fatefully, in a moment of vision, in resolute repetition.
The existential Interpretation of Dasein's historicality is constantly getting eclipsed unawares. The obscurities are all the harder to dispel when we have not disentangled the possible dimensions of the appropriate inquiry, and when everything is haunted by the enigma of Being, and, as has now been made plain, by that of motion.2 Nevertheless, we may venture a projection of the ontological genesis of historiology as a science in terms of Dasein's historicality. This projection will serve to prepare us for the clarification of the task of destroying the history of philosophy historiologically—a clarification which is to be accomplished in what follows.x
¶ 76. The Existential Source of Historiology in Dasein's Historicality
We need not discuss the Fact that historiology, like any science, is, as a kind of Being of Dasein, factically 'dependent' at any time on the 'prevailing world-view'. Beyond this, we must inquire into the ontological possibility of how the sciences have their source in Dasein's state of Being. This source is still not very transparent. In the context which lies before us, our analysis will acquaint us in outline with the existential source of historiology only to the extent of bringing still more plainly to light the historicality of Dasein and the fact that this historicality is rooted in temporality.
If Dasein's Being is in principle historical, then every factical science is always manifestly in the grip of this historizing. But historiology still has Dasein's historicality as its presupposition in its own quite special way.
This can be made plain, in the first instance, by the suggestion that historiology, as the science of Dasein's history, must 'presuppose' as its possible 'Object' the entity which is primordially historical. But history must not only be, in order that a historiological object may become accessible; and historiological cognition is not only historical, as a historizing way in which Dasein comports itself. Whether the historiological disclosure of history is factically accomplished or not, its ontological structure is such that in itself this disclosure has its roots in the historicality of Dasein. This is the connection we have in view when we talk of Dasein's historicality as the existential
1 '... eine Entgegenwärtigung des Heute ...'
2 '... und in allem das Rätsel des Seins und, wie jetzt deutlich wurde, der Bewegung sein Wesen treibt.'