In what follows I wish to comment critically on Heidegger's extraordinary lecture course at Marburg in the Summer semester of 1924. This course was entitled “Basic Concepts or Aristotelian Philosophy," which would seem to make the catalogue or concepts in Metaphysics Delta the center or its concerns. But instead it focuses for long stetches on Aristotle’s Rhetoric, and does so in a way unparalleled in any philosophical studies we have available. Indeed it is Heidegger’s special genius here to have recovered Aristotle’s Rhetoric for philosophy as such and to have gotten it back from the extreme periphery of Aristotle’s works Co which the tradition of philosophy, including Aristotle himself, had relegated it.Continued.
How was this recovery possible? And why was it possible for Heidegger but not for anyone else? In part the answer lies in Heidegger’s unique penetration behind the theoretical logos apophantikos, the proposition or declarative sentence (Aussagesatz), that had become philosophy's exclusive and unquestioned paradigm for all human discourse. Early on Heidegger saw what philosophy, even Aristotle's “more inceptive" philosophy, had largely forgotten, namely that theory's logos apophantikos was not the original and basic form utterance, but rather that it was somehow derivative and “multiply founded” (mehrfach fundiert). He saw, that is to say, that it was based in a layer or speaking that, in mm, was based in yet another layer of speaking which was its ultimate and original ground (Grund). This ground was the basis, the floor and soil at the bottom of it, as it were, der Boden not only on which it rested but in which it was embedded and from which it “grew." Thus Heidegger could reverse Aristotle’s own reduction and, with that, he reversed the priorities of all subsequent philosophy or language: the rhetorical enthymeme was not, as Aristotle had sought, to be based on the dialectical syllogism, which in turn was to be based on the demonstrative syllogism built of logoi apophanzikoi or propositions. On the contrary, as Heidegger saw it, theoretical speech’s detached propositions about an objectified reality merely lying on hand before us in static presence were an abstraction from what we say to each other in our engaged practical taking care of things (Besorgen) within in the world in which these things, and other people there with us in the world, meet up with us. As he saw it, science's apodeixis or demonstration was an abstraction from dialetic's dialegesthai or talking something through theoretically. And dialectic’s dialegesthai was, in turn, an abstraction from rhetoric's practical peithein or persuasion.
Accordingly, these lectures of 1924, in applying the method of Sein und Zeit's Destruktion, propose initially to take down the abstract conceptual talk of Aristotle’s metaphysics and to lay bare our original lived existence in the world in which his metaphysical concepts have their ground and basis. The movement here, the same as in Sein und Zeit, is back from a theoretical looking on and looking at things, and back to Dasein’s practical, concermed and worried being-there in the world among things. And as in Sein und Zeit the Areadnean thread to be followed in this “"step back" is our speech (Rede, logos). The logos ousias or conceptual definition of “what it was to be a thing,” arrived at in dialectic, its to ti en einai, is to be traced to the logos or argument we make to each other in getting things done in our every day existence, and it is precisely from Aristode's Rhetoric that we learn about this original logos. Hence we can say that even in 1924 it was Heidegger's project or a fundamental ontology - his project elaborated in Sein und Zeit of founding and grounding abstractions in original being as this meets up with us “in the world” - that allows him to penetrate the “obvious” primacy of theoretical language and to redeem the “obviously” inferior “mere” rhetoric.
Pp. 316-7