In Being and Time, Heidegger says that Dasein's "bodily nature" (Leiblichkeit) implies "a whole problematic of its own", adding "we shall not treat it here". I will inquire into why Dasein's bodily nature was problematic for him. He hadn't given us any explicit answers to this question. However, in some of his texts (Metaphysische Anfangsgruünde der Logik and Zollikoner Seminare), we can find some clues about it. By following these texts, I will try to reveal that Heidegger is implicitly giving Dasein's bodily nature a double potision in his analysis of Dasein: one is that Dasein's bodily nature is based on "in-theworld-being", the other is that it has "neutral" Dasein diversified.
So I argue that this double potision makes Heidegger's "bodily nature" problematic. In addition, I will comfirm this double potision of Dasein's bodily nature, in a manner different from his, by describing the bodily situation, which Heidegger himself illustrates in Zollikoner Seminare. He pays much attention to the fact that we are offen absorbed in thinking about something while walking around. I will point out that this "while ing" includes both potisions of Dasein's bodily nature: walking around itself is based on "in-the-world-being" of Dasein, while we find out where we are in the world through our relation to each of the ready-to-hand (das Zuhandene) in our walking around.