The subject of this paper is Heidegger’s understanding of world and world-formation [Weltbildung] in his lecture The Fundamental Concepts of Metaphysics (GA 29/30) and his references to the idealistic philosophy of Schelling, the ancient thought of Aristotle and Heraclitus. I will put forward the following thesis: World is prevailing [Walten] and, as this prevailing, it is the being of beings as such as a whole in the projection of world that lets it prevail. In this paper, I will clarify how (...) the world prevails, how Dasein forms the world, and the significance of physis, logos and as-structure [als-Struktur] in this context. I will also show that Heidegger’s concept of world-formation can be thought together with his concepts of being-in-the-world and worldhood. Finally, I will discuss some of the difficulties in Heidegger’s understanding of the world and propose some solutions. (shrink)