In his Winter Semester 1937–38 lecture course, Heidegger presents publicly parts of the fifth jointure of his Contributions to Philosophy entitled The Ones to Come. The basic question of this course is: why and how did the original Greek understanding of truth as ἀλήθεια, unconcealment, become the metaphysical understanding of truth as correctness? Plato and Aristotle understood truth no longer as unconcealment, but as correspondence between thinking and entities. Truth became the correctness of the judgment in which we say what entities are in their being. However, in the unconcealment of entities, being itself remains concealed. The history of metaphysics from Plato to Friedrich Nietzsche is determined by the guiding question of ontology: What are entities as entities? Because Plato and Aristotle failed to interpret and ground “ἀλήθεια” from its origin as the gifting refusal of the truth of being, metaphysics became obsessed with entities and neglected to think the clearing of being. The forgottenness of being in metaphysics is, at the same time, the abandonment of being, which in turn leads to the need or “distress” of modern times. This distress is the dislocation of being-there. Our existence has become uprooted and groundless. At the extreme point of the abandonment of being, we can experience this distress in its grounding attunement and heed its warning.
The task of this nonmetaphysical thinking is to bring the guiding question of metaphysics to the basic question of thinking, that is, what is the meaning of being? This question is basic, because it inquires back to the ground of metaphysics. It inquires after the truth of being, that is, the unconcealment of entities, the ground as abground (Abgrund). In the meditation on the first beginning that experienced truth and posited the truth of entities without asking about truth, as such, post-metaphysical thinking prepares for the other beginning that experiences the truth of being and asks about the origin of truth as unconcealment in order that thinking can be delivered or “owned over” (übereignet) to beyng. This preparation tries to overcome the forgottenness of being and nihilism by embarking upon the path of being-historical thinking.