contingencies of the late Weimar era. The empathy Nielsen lends to his glosses on Jews seeking accommodation with the New Right is analytically effective. Two criticisms attend this positive review. First, a comprehensive sociological analysis of the Jewish Right is missing. What were its numbers and its sociopolitical depth? Were these conservative Jews a proxy for a larger social group and to what extent did these actors alter the broader contours of the Jewish-German dialogue? Quantifying this social group’s size, regional distribution, and political import would have helped readers grasp the argument’s parameters. Second, the book’s late entry into the long nineteenth century prompts ques- tions about previous decades of Jewish-German relations, such as why Jews harbored such positive attitudes toward the German state. The successes and failures of Jewish acculturation in previous generations inflect the storyat hand, hence a succinct overview, however brief, would have helped readers. That history only heightens the tragedy of twentieth-century Jews caught between Heimat and hatred. JAMES M. BROPHY UNIVERSITY OF DELAWARE doi:10.1017/S0008938920000205 The Mathematical Imagination: On the Origins and Promise of Critical Theory. By Matthew Handelman. New York: Fordham University Press, 2019. Pp. 278. Paper $28.00. ISBN 978-0823283828. Matthew Handelman’s book proposes the following narrative: Critical theory has been at odds with mathematics, to a large extent due to the Frankfurt School’s critique of the Enlightenment and instrumental reason. But in the Weimar Republic, a few intellectuals were inspired by mathematics to develop critical and/or Jewish-mystical theories of knowl- edge. Today, as digital humanities mathematize humanistic research, we might be inclined to follow the Frankfurt School thinkers and decry this as an anti-critical development. However, we may also follow the aforementioned Weimar-era thinkers and use mathematics to open up new forms of critical knowledge. The book opens with a chapter about the Frankfurt School (focusing on Theodor Adorno and Max Horkheimer, and to a lesser extent Walter Benjamin), who criticized mathematics as a form of thought detached from real materiality. As such, mathematics was seen as a tool for depoliticizing thought by making it formal and immaterial (in both senses of the word). The next three chapters counter this stance by studying the work of Gershom Scholem, Franz Rosenzweig, and Sigfried Kracauer, who used mathematics to develop new mystical-critical approaches. Scholem drew an analogy between mathematics and knowledge of the divine: both indicate an inexpressible world removed from our own (that of platonic pure forms and that of the divine, respectively). Yet just as the meaningless, formal symbols of mathematics can, precisely by their meaninglessness, produce knowledge of the platonic world of abstract mathematics, likewise, some forms of privative poetic language, which break meanings down, can produce knowledge of the divine. As modern mathematics produces this knowl- edge with its unhistoricized formalism, so knowledge of the divine can arise even as historical BOOK REVIEWS 475 https://doi.org/10.1017/S0008938920000369 Published online by Cambridge University Press