William McNeill on φρόνησις.

The project of Destruktion, the “destructuring of the history of ontology” announced in Being and Time, would seek to retrieve and to open up an entirely other dimension of Being, a dimension foreclosed by the Greek beginning and yet awaiting us precisely as the unthought of that beginning and the tradition to which it gave rise. The destructuring would take as its guiding thread an understanding of the Being of Dasein—designating the being that we ourselves in each case are—as radically temporal, never simply present-at-hand, and essentially inaccessible to theoretical apprehension. Yet the critical resource for this analytic of the Being of Dasein was, for the early Heidegger, itself provided by Greek philosophy: it was Aristotle’s insight into the Being of the human being as action, praxis, and its authentic mode of self-disclosure, phronēsis, that led Heidegger to see the radically different kind of temporality pertaining to human existence in contrast with the theoretically ascertained time of nature as something present- at-hand. This provided a key insight into the essence of “truth” (alētheia) as unconcealment. Aristotle’s insight into this more primordial sense of alētheia or “truth” as the knowing self-disclosure of our radically temporal Being-in-the-world as praxis, as opposed to truth conceived as a property of logos, judgment, or theoretical knowledge, was a forgotten thread of Greek philosophy that could shed light upon the limits and foundations of the theoretical tradition that dominates the subsequent history of ontology.

While Heidegger, in the 1920s, certainly radically transforms Aristotle’s analysis of phronēsis, opening it up phenomenologically and exposing the radical, “ekstatic” temporality it implies, and showing how this originary and primordial temporality constitutes the horizon for every understanding of Being, there can be no doubt that, following Aristotle’s distinction between technē and phronēsis, he rigorously differentiates Dasein’s authentic self- understanding from any kind of “technical” understanding. The model for authentic self- understanding is the phronēsis that, for Aristotle, guides excellent or virtuous praxis; by contrast, understanding oneself in terms of a particular work—whether an already existing work, or a work to be produced—is inevitably an inauthentic self- understanding that projects Dasein’s Being upon the Being (or possible Being) of an entity within the world that has the character of something present- at-hand or ready- to-hand. Any ontological understanding of one’s own Being emerging from the horizon of technē is clearly problematically reductive. And yet, why, then—given the entire rigor and phenomenological persuasiveness of these analyses by which technē is decisively sidelined as a reductive and inferior mode of disclosure, responsible, as it were, for the entire cumulative sins of the Greek- Western philosophical tradition—why, then, does technē return so centrally as arguably the issue to be thought throughout Heidegger’s work from at least the mid- 1930s on?

From "Tracing technē".