  In fact, however, we have no way of knowing exactly which paintings Heidegger saw at the 1930 exhibit of Van Gogh’s works in Amsterdam he later recalled having  visited.[88] The debate surrounding Heidegger’s interpretation of Van Gogh’s painting can be traced back to the fact that initially it is not even clear which painting Heidegger is referring to when he invokes an allegedly “well known painting by Van Gogh, who painted such shoes several times.”  (Here are links to three of them, dated  Spring 1887,   early 1887,  and June 1886.)   If Heidegger was aware that Van Gogh painted no fewer than five works  titled “A Pair of Shoes”  between 1886 and 1888, plus several other pairs of wooden farmer’s  clogs,  leather clogs, and paintings of  more than one pair of shoes,   then he does not seem to have thought this fact significant. The art historian who was closest to Heidegger, Heinrich Petzet, proposes that the “various versions [of Van Gogh’s ‘A Pair of Shoes’] each show the same thing,” and this might well be what Heidegger himself thought (if he ever even thought about it): Each of these paintings manifests the struggle between earth and  world.[89] Yet, there are lots of other differences between these paintings; anyone who studies them will quickly see that they are not even all paintings of the same pair of shoes. Given the subsequent fame of Heidegger’s essay, it is quite understandable that both art historians and phenomenologists would want to determine precisely which painting Heidegger was referring to in “The Origin of the Work of Art” so as to be able to evaluate his interpretation for ourselves. When the eminent art historian Meyer Schapiro took up the task of identifying the painting in the 1960s, however, the mystery over which shoes Heidegger was actually referring to exploded into a whole new controversy.