According to Heidegger, "being-in-the-world is the basic composition (Grundverfassung) of Dasein" (MFL, 169/217). As such, it belongs to the essence (Wesen) of Dasein that insofar as "Dasein factically (faktisch) exists, then its existence has the structure of being-in-the-world" (MFL, 169/217). This means that being-in-the-world is not something which structures Dasein's existence only on certain occasions, but rather that "it must always already have been ontically experienced" (">BT, 86/59). The pertinent question that Heidegger asks with respect to this structure is whether knowing (erkennen) the world, in the sense of the perception of natural entities, is phenomenally sufficient to establish being-in-the-world as the basic composition of Dasein? More precisely put, the question is one of whether the "already being-alongside-theworld (Schon-bei-der-Welt)" (BT, 88/61) constitutive of Dasein's Being is phenomenally manifested as "just a fixed staring at something that is purely present-at-hand" (Ibid)?