humanizing and universalizing the Jew at the same time. Both men believed that by viewing Jewish religion through the prism of evolutionary theory they could construe Jewish difference in such a way as to counter the threat to assimilation posed by racial antisemitism. Jewish views of Darwinism and the Holocaust Mordecai Kaplan (1881–1983) and Hans Jonas (1903–1993) were two influential Jewish religious thinkers of the twentieth century who engaged seriously with scientific knowledge and, in particular, with Darwinism. The writings of two twentieth-century New York-based religious thinkers shared a common concern to find an alternative approach to the problem of evil in general and to the religious challenge of the Shoah in particular. For Kaplan, the founder of Reconstructionist Judaism, it was possible to draw upon his already well-developed, scientifically augmented (or inspired) revisions of the Jewish religion and the Jewish God. Kaplan's writings from the 1930s onwards manifest an interest in evolution in at least four different although related contexts. First, evolution, in the sense of development or change, is used as a justification for Kaplan's reconstructionist project; Judaism is a living organism transforming and adapting to its changing environment. Second, evolution is presented as a divine process or principle that brings order out of chaos, in the sense of the volution of the cosmos. Third, the biological evolution of mankind. The evolution of plant and animal life, including human life, by means of Darwinian natural selection was a given, as far as Kaplan was concerned, although there is no doubt that in his mind natural selection was inadequate to explain human evolution in its entirety—or, at least, those aspects of human evolution that Kaplan was most interested in, namely, the ethics of a community. This led him to develop his theory of "spiritual selection," which added a complementary—and competing—force for selection to the mix of evolutionary pressures that shaped human evolution, including natural selection and sexual selection. Fourth, Kaplan discusses evolution in relation to what we would now call Social Darwinism, that is, the application of a theoretical framework for organic biology to human society, and in particular the Nazi theory of race competition. Kaplan, as one might expect, is hostile to such ideologies, but his key reason is that they threaten to undermine his understanding of humans as partners with the divine in bringing meaning and order to the universe. For the philosopher of technology, Jonas, the