This Winter Semester 1925–26 lecture course is a milestone on the way to Being and Time. It moves toward the interface where language is born. Heidegger wants to develop a philosophical logic that can discover existentials and their hermeneutically indicative sentences. In the first part of the course, he rehearses his own prior steps toward such a logic. After a discussion of Edmund Husserl’s critique of psychologism, he criticizes the neo-Kantian sense of judicial truth as validity. To get to the origin of truth, it is necessary to return to Aristotle’s prejudicative truth of νοῦς or simple apprehension. This truth of intuition binds Aristotle and Husserl together in a juxtaposition of Greek and German thinking.
Husserl’s principle of all principles is intuition, that is, the giving and having of an entity in its bodily presence. Heidegger shows that underlying intuition there is a more fundamental understanding of that intuition which at once understands itself. The primary form of simple apprehension is a having of something as something in the ways we can use it. We discover entities first as pieces of equipment, which are given in their in-order-to. The “as” of primary understanding is the original articulating of my getting around and dealings with the world. In this, we acquire the habits of our habitat that constitute our most immediate having. The “as” of primary understanding makes it possible for us to explicate in assertions the structure of our being. The “as” of primary understanding can thus become the hermeneutic “as.” Assertion is a demonstrative letting something be seen or uncovering. Heidegger can now distinguish between worldly assertions, which let entities be seen in their being, and categorial assertions or existentials, which indicate the being of being-there.
After the Christmas break, Heidegger abandons the original outline of his course. Instead of Aristotle’s question of truth, he discusses Immanuel Kant’s doctrine of schematism. This interpretation of Kant would ultimately result in his later book, Kant and the Problem of Metaphysics. Heidegger shows that the original self-affection of the mind or pure consciousness is time. Time gives itself unthematically as the constant precursory encounter that lets entities be. It lets entities be seen and makes our apprehension of entities possible. The making present of any entity as something is a comportment of being-there, for being-there is itself time. The present or now as making present is a basic possibility of the being of being-there, that is, existence. Here, at the end of the course, Heidegger introduces the existential vocabulary that would dominate Being and Time.