  For Heidegger, then, the essential tension between “world” and “earth”—the dynamic back-and-forth whereby some things (or aspects of things) cannot emerge into the light of our intelligible worlds without others withdrawing into the background (which means that it is impossible for everything to take place in intelligibility all at once)—names the basic conflict in the structure of intelligibility, a conflict which is ultimately  responsible for the historical unfolding of what  is.[71] Once we realize this, we can see that Heidegger’s only other major reference to Van Gogh’s painting (in 1935’s The Introduction to Metaphysics) again follows the same basic sequence of phenomenological steps. This important passage turns once more on the double meaning of (the) “nothing” (which Heidegger again seeks to suggest with the subtly ambiguous locution, “nothing else”):