radically, and even points to the possibility of thinking of care in terms of ecstatic temporality through a retrieval of the Greek middle-voice form.53 Heidegger suggests that we should think care (Sorge), here associated with Umsicht (φρόνησις) or circumspection, as comparable to the way the middle voice operates in ancient Greek, as a movement and countermovement, as a recoil of being; in which case, he says, Bekümmerung would be die Sorge der Existenz, the care that belongs to existence.54 This probably marks the place of a major shift in Heidegger’s thinking that prepared the way for Sein und Zeit. The back-and-forth double play between fallenness and existence that is signaled by Heidegger’s invocation of the Greek middle voice also indicates a suggestion by Heidegger on how to read the relationship between facticity and existence, even in his later work. As care reveals being in the world, so the existential moment opens Dasein to the whole of being. But, the existential Gegen opens Dasein to a not-being that belongs to its very way of being. Heidegger suggests that Aristotle recognized this in his notion of στέρεσις, a notion of nonbeing and refusal that Aristotle says (against the Eleatics) belongs to being itself. Referring to chapter 7 of the Physics, Heidegger says that the basic category of στέρεσις dominates Aristotle’s ontology. Στέρεσις means lack, privation. It can also mean loss or deprivation of something, as in the example of blindness, which is a loss of sight in one who by nature sees. Στέρεσις can also mean confiscation, the violent appropriation of something for oneself that belongs to another (Met. 1022 b33). Finally, Aristotle often calls that which is held as other in an opposition of contraries a privation. Heidegger will point out in his later essay on Physics B1 that Aristotle understands this deprivation as itself a kind of εἶδος.55 Thus, στέρεσις is the lack that belongs intrinsically to being. According to Heidegger, with the notion of στέρεσις Aristotle reaches the pinnacle of his thinking about being. Heidegger even remarks that Hegel’s notion of negation needs to be returned to its dependency on Aristotle’s more primordial conception of the not.56
In the context of Heidegger’s discussion of privation and ontological lack, it becomes clearer why Heidegger introduces a discussion of death and the finality of factical life in this 1922 essay on Aristotle. Factical life is such that its death is always somehow there for it, something that always stands in sight for it as an obstinate and uncircumventable prospect of life. What Heidegger discovers here, then, is a kind of double movement, a movement and a countermovement, a dual movement of descent and recall that unfolds the span within which human life is. This doubling, middlevoiced κίνησις is the authentic mode of being of life.