Michael Friedman on Heidegger's response to Carnap's attack in the journal Erkenntnis
It is noteworthy, finally, that Heidegger was aware of Carnap’s attack and, indeed, explicitly responded to it—in a draft of the original 1935 lecture course, Introduction to Metaphysics, that does not appear in the published version in 1953. Heidegger explains how, with the collapse of German idealism in the second half of the nineteenth century, the philosophical understanding of Being degenerated into a consideration of the “is”—that is, a logical consideration of the propositional copula. He continues in a memorable paragraph which is worth quoting in full:
Going further in this direction, which in a certain sense has been marked out since Aristotle, and which determines “being” from the “is” of the proposition and thus finally destroys it, is a tendency of thoughtPp. 21-2
that has been assembled in the journal Erkenntnis. Here the traditional logic is to be for the first time grounded with scientific rigor through mathematics and the mathematical calculus, in order to construct a “logically correct” language in which the propositions of metaphysics—which arc all pseudo-propositions—arc to become impossible in the future. Thus, an article in this Journal II, pp. 219 ff. bears the title “Uberwindung der Metaphysik durch logische Analyse der Sprache.” Here the most extreme flattening out and uprooting of the traditional theory of judgment is accomplished under the semblance of mathematical science. Here the last consequences of a mode of thinking which began with Descartes are brought to a conclusion: a mode of thinking according to which truth is no longer disclosedness of what is and thus accommodation and grounding of Dasein in the disclosing being, hut truth is rather diverted into certainty—to the mere securing of thought, and in fact the securing of mathematical thought against all that is not thinkable by it. The conception of truth as the securing of thought led to the definitive profaning [Entgötterung] of the world. The supposed “philosophical”
tendency of mathematical-physical positivism wishes to supply the grounding of this position. It is no accident that this kind of “philosophy” wishes to supply the foundations of modern physics, in which all relations to nature are in fact destroyed. It is also no accident that this kind of “philosophy” stands in internal and external connection with Russian communism. And it is no accident, moreover, that this kind of thinking celebrates its triumph in America. All of this is only the ultimate consequence of an apparently merely grammatical affair, according to which Being is conceived through the “is,” and the “is” is interpreted in accordance with one’s conception of the proposition and of thought.