The Makings of History / Revisiting Arthur Ruppin
https://www.haaretz.com/1.5309866
Arthur Ruppin believed that the realization of Zionism demanded "racial purity" among the Jews.
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Belief in the theory that Ashkenazim were the definitive Jewish type in the modern era enabled Ruppin to accept German racial theory, and effectively remove the majority of Jews from the Semitic category. Indeed, in his view, the original, "healthy" Jews who were responsible for the virtuous aspects of the culture belonged, in racial terms, to the Indo-Germans.