In this essay wish to point to an ambiguity in Heidegger's concept of the futuricity of Dasein and show how this ambiguity is to be found at the core of authentic temporality in Being and Time. This ambiguity is not accidental but, rather, resuits from the conflict between two ways of truth implicit in that work: that of praxis and that of poiesis. two meanings of futuricity which am pointing to in Being and Time can be called the simple future and the future past. latter designation is suggested by an article by David Carr in which he suggests that Heidegger's concept of futuricity expresses itself in the future perfect tense: I will have been . . .' It is my claim, however, that in Being and Time another futural movement is recognized as a movement into a future which is an unknown land, where all continuity is for a moment suspended. This futural movement is kairological,2 whereas the movement of Being-towards-death is chronological. latter sees Dasein's finitude in its mortality, the former in its natality. Heidegger's terminology in Being and Time, as Franco Volpi has shown, is a translation, a repetition (Wieder-holung), of Aristotelian terminology. A basic claim of this essay is that in Being and Time Heidegger is playing with a fundamental distinction that he derived from Aristotle, namely, that between praxis and poiesis (Zuhandenheit). It will be further claimed that this distinction lies at the heart of Heidegger's understanding of temporality and more specifically the question regarding futuricity. much discussed question of the relative priority of theory and practice in Being and Time ignores the fact that theory itself only arises for Heidegger from a breakdown-a failure-of one aspect of human practice, namely, that of poiesis.4 distinction between poiesis and theory (Vorhandenheit) is internal to the aspect of work which itself is contrasted with praxis.5 Praxis and poiesis are two orders of Dasein's being-in-the-world. Despite the fact that as a concept is only once discussed in Being and 7T-me, there is underlying that work a concept of order which, on that one occasion, Heidegger expresses as follows: The principle of order has its own content, which is never to be found by means of such ordering, but is already presupposed in it.6 In other words, every breakdown of an order reveals a more fundamental order (cosmos, world), which is always already there. Hence it is that, with the breakdown of the tool, the underlying order of the referential totality is opened up. Everything new is thus relative. It is a new opening up of what is always already there. This concept of order is poietic. Whether there is a praxical order in Being and Time is a question which lies at the root of my investigations. To aid this investigation it should be noted that there is in Heidegger's concept of order and indeed his discussion of various phenomena throughout Being and Time an implicit logic of failure: when the ordering of a process fails, through that failure is revealed a more fundamental order. But if there are different orders (and those of praxis and poiesis reflect different orders of truth), then might not the logic of failure operate differently in each? Indeed, believe this to be the case and would add for this reason to the logic of failure one of mutual effect: the nature of the ordering that fails modifies and is modified by the revealed order. If this is the case, the concept of order underlying Being and Time is poietic and not praxical. Heidegger's treatment of poiesis begins with the insight that things are first encountered as things with a purpose; they refer to some end beyond themselves. Furthermore, the thing, as tool, is in itself inconspicuous. Circumspection (Umsicht) is directed away from the tool. When the tool breaks or the work is otherwise impeded,' there occurs a rupture (Bruch) and circumspection crashes into the void (Die Umsicht stoft ins Leere). …