idealism, which starts first with a subject, which then in some manner supplies an object for itself. To start with an I-thou relationship as a relationship of two subjects would entail that at first there are two subjects, taken simply as two, which then provide a relation to others. Rather, just as the Dasein is originally being with others, so it is originally being with the handy and the extant. Similarly, the Dasein is just as little at first merely a dwelling among things so as then occasionally to discover among these things beings with its own kind of being; instead, as the being which is occupied with itself, the Dasein is with equal originality being-with others and being-among intraworldly beings. The world, within which these latter beings are encountered, is—because every Dasein is of its own self existent being-with others—always already world which the one shares with the others. Only because the Dasein is antecedently constituted as being-in-the-world can one Dasein existentielly communicate something factically to another; but this factical existentiell communication does not first constitute the possibility that one Dasein has a single world with another Dasein. The different modes of factical being-with-one-another constitute in each case only the factical possibilities of the range and genuineness of disclosure of the world and the different factical possibilities of intersubjective confirmation of what is uncovered and of intersubjective foundation of the unanimity of world-understanding and the factical possibilities of the provision and guidance of existentiell possibilities of the individual. But it is again not an accident that we elucidate for ourselves what world means in an ontological sense chiefly in terms of intraworldly beings, to which there belong not only the handy and the extant but also, for a naive understanding, the Dasein of others. Fellow humans are certainly also extant; they join in constituting the world. For this common concept of the world it is sufficient to point to the concept of the cosmos, for instance, in Paul. Cosmos here means not only the whole of plants, animals, and earth, but primarily the Dasein of the human being in the sense of God-forsaken man in his association with earth, stars, animals, and plants.

World exists—that is, it is—only if Dasein exists, only if there is Dasein. Only if world is there, if Dasein exists as being-in-the-world, is there understanding of being, and only if this understanding exists are intraworldly beings unveiled as extant and handy. World-understanding as Dasein-understanding is self-understanding. Self and world belong together in the single entity, the Dasein. Self and world are not two beings, like subject and object, or like I and thou, but self and world are the basic determination of the Dasein itself in the unity of the structure of being-in-the-world. Only because the "subject" is determined by being-in-the-world can it become, as this self, a thou for another. Only because I am an existent self am I a possible thou for another as self. The basic condition for the