of being and nonbeing because only in this way could the truth of being appear in its difference. Heidegger says: “only when we turn thoughtfully toward what has already been thought (but presupposed and then forgotten) will we be turned to use for what must still be thought.”30 It is with this question that Heidegger begins Sein und Zeit.31
Before continuing with his interpretation of Aristotle’s Physics B 1, Heidegger summarizes what Aristotle has so far accomplished and outlines the importance of his confrontation with Antiphon. We have determined through epagōgē that natural beings are in movement. Not in the sense that they are at any given moment necessarily in motion (as regards to locomotion or alteration, etc.) but in the sense that being-moved is their way of being. It is this way of being that directs and makes possible the kinds of motion that beings undergo. This way of being is phusis. Phusis is the archē of beings that move according to their nature. Phusis is not motion but the archē of the motion in beings such that it lets them be the beings they are. The archē both directs and governs the emerging forth and lets that which directs and governs the upsurgence emerge into unconcealment. It is both Ausgang and Verfügung thought in their togetherness. The telos, that toward which a being reaches and in which it fulfills itself, directs the coming-to-be of a being. That “from which” and “out of which” a being emerges is the origin. But both the origin and the telos are essentially the same. Phusis is both. It is ausgängliche Verfügung. The archē holds a being in its togetherness and lets it come forth as a whole. The diverse moments and phases of the coming to be of a natural being do not contradict the meaning of being as ousia. Rather being-moved is the way in which natural beings fulfill their ousia. Therefore only by understanding kinēsis in the proper way can we understand the “nature” of phusis as the archē of the being-moved of natural beings.
Heidegger points to the beginning of Chapter III of Book II of the Physics in support of this seemingly circular reasoning. There Aristotle says:
Since phusis is the originating and governing over being-moved and thus over the upsurgence which bursts into the open, our methodos must not allow that kinēsis essentially is to remain in concealment. For whenever kinēsis remains unfamiliar, phusis also remains in unfamiliarity.” (Physics 200 b12–15; WBP 341)
Aristotle’s “method” requires both a comportment toward kinēsis and toward phusis. Unless we see what kinēsis is, that is, how kinēsis is in its