Steven Galt Crowell on the later phase of Heidegger's way of thinking.
In the final phase of his thinking Heidegger follows out the logic of his project of deconstructing and overcoming metaphysics—seen now as the history of being (Seinsgeschichte)—to the point where its guiding terms, “being” and “truth,” are themselves deemed unsuitable for naming the topic that provokes a new way, another beginning, for thought, namely, Ereignis. This termis meant to suggest that “event” whereby “there is” the ontological difference between being and beings. Prior to both being and time, Ereignis grants or gives both (es gibt Sein, es gibt Zeit). Heidegger’s postmetaphysical thinking nevertheless still draws upon the “essential help of phenomenological seeing,” which, in counterpoint to the technological ordering of all reality that is the heritage of metaphysics, he cultivates explicitly in a series of essays devoted to recovering the poetic possibilities in mundane things.
Though its roots lie earlier, this last phase begins publicly with the 1947 “Letter on Humanism,” which marks Heidegger’s return to publication after the silence of the war years. Here Heidegger is at pains to distinguish his project from then-current existentialism. Refusing to assimilate his earlier work to a humanism that places man or “human existence” at the center of philosophy—as had Sartre’s interpretation of Being and Time—Heidegger insists that the task is to think being itself and to determine the human only on the basis of such essential thinking. In Heidegger’s view Being and Time already indicated the need to make this turn, but his subsequent thought failed, he now believes, because it remained too dependent on the “language of metaphysics.” In his emphasis on will and decision, for example, the disclosure of a normative meaningful space, or world, remained tied to the very metaphysical subjectivism Heidegger criticized in Nietzsche. As a result, the theme of language itself, first explored in the lectures on Hölderlin, emerges as central in Heidegger’s essays from the 1950s. To overcome metaphysics, to think the truth of being in a non- (or post-) metaphysical way, a new relation to language is required. In the “Letter on Humanism,” language is identified as the “house of being,” and the image of human being as language user is displaced by the image of human being as one who “dwells” in the house, one who is the “shepherd” of being. In subsequent essays Heidegger emphasizes the proximity of postphilosophical “thinking” (as the response of the thinker to the call or claim of language) and the primordial “saying” of poetry.
By the end of this phase, as can be seen in the 1962 essay on “Time and Being” and the 1964 essay “The End of Philosophy and the Task of Thinking,” Heidegger finally comes to reject all efforts at overcoming metaphysics. If the task of thinking is to think (the meaning of) being itself, this can only be done in light of that event (Ereignis) whereby “there is” being. Metaphysics, in contrast, always thinks being in light of beings, that is, as the being of beings. The very interest in overcoming this tendency (including Heidegger’s own earlier preoccupation with the ontological difference) is now seen to keep thought in thrall to beings. Hence, in a line that anticipates some of the themes of Derridean deconstruction, Heidegger argues that one should “cease all overcoming and leave metaphysics to itself.” Heidegger is thus led to abandon the metaphysical language he had sought to reappropriate for his “other” thinking. With pointed reference to the method of phenomenological seeing, which nourishes itself upon the clearing (Lichtung) that grants and enables such seeing, Heidegger argues that while metaphysics has always thought about what shows up in the clearing—namely, beings—it “knows nothing of this clearing itself.” More precisely, clearing must here be thought verbally as opening, and the philosophical term “truth” (aletheia) does no more than name it while remaining blind to its character. Hence, the clearing cannot be called the “truth” of being, and the “question of the aletheia, of the unconcealedness as such, is not the question of truth.” Reflecting on the matter of thought, then, leads Heidegger to replace the metaphysical terms of his earlier project—“being” and “time”—by the postmetaphysical “clearing” (Lichtung) and “presence” (Anwesenheit).