海德格在1929年的〈什麼是形上學？〉，開始討論「無」，提到了「無自無」(Das Nichts selbst nichtet)。〈什麼是形上學？〉所說的無和老子所說的無的類似性，經常被注意到；但是，海德格存有思想所說的「有與無的共同隸屬」(Sein und Nichts gehören zusammen)和老子所說的有無玄同的思想結構上的共通性，卻未被重視與展開。筆者此文就道家的無與形上學的根本問題，在謝林、尼采、海德格的思想脈絡之中，加以探討。筆者的討論主要集中於《海德格全集》第42冊的Schellings Abhandlung ber das Wesen der Menschlichen Freiheit (1809)（《謝林的論人類自由的本質(1809)》）一書以及海德格講於1936-1940年之間的弗萊堡大學的「尼采講座」，並涉及海德格與日本京都學派學者九鬼周造、西谷啟治的交互影響，以此為背景，筆者重新討論海德格存有思想所說的「有與無的共同隸屬」和老子所說的有無玄同的思想結構上的共通性的問題。

Heidegger discussed the topic of ”Nothingness” (Das Nichts) on 1929 in his ”What is Metaphysics?”. He mentioned the ”Das Nichts selbst nichtet”. This thinking of Nothingness is similar with Laotze's ”Wu” (無). This similarity is often mentioned, but its deeper meaning in the background of the thinking of ”Sein und Nichts gehören zusammen” (Heidegger) and the Being and Nothingness belonging together in the darkness of Tao (Laotze) is disregarded. This article tackles this disregarded topic in two perspectives. First, I reexamine volume 42 of Heidegger's complete works ”Schellings Abhandlung über das Wesen der Menschlichen Freiheit (1809)” in order to illuminate the trend from Philosophy of reason and will (Heidegger discussed on Kant and Nietzche) to the philosophy of non-will (Heidegger's discussion on Schelling and himself). Second. I reexamine Heidegger's discussion on Nietzsche (Nietzsche, Erster Band, Zweiter Band, Pfullingen, 1961) and its influence on Kyoto school philosopher K. Nishitani. In these new background I exposits the intercultural communication between Heidegger and Laotze about ”Nothingness”.