Until very recently, the idea of ancient Jewish sciences would have been considered unacceptable. Since the 1990s, Early Modern and Medieval Science in Jewish sources has been actively studied, but the consensus was that no real scientific themes could be found in earlier Judaism. This work points them out in detail and posits a new field of research: the scientific activity evident in the Dead Sea Scrolls and early Jewish pseudepigrapha. The publication of new texts and new analyses of older ones reveals crucial elements that are best illuminated by the history of science, and may have interesting consequences for it. The contributors evaluate these texts in relation to astronomy, astrology, and physiognomy, marking the first comprehensive attempt to account for scientific themes in Second Temple Judaism. They investigate the meaning and purpose of scientific explorations in an apocalyptic setting. An appreciation of these topics paves the way to a renewed understanding of the scientific fragments scattered throughout rabbinic literature. The book first places the Jewish material in the ancient context of the Near Eastern and Hellenistic worlds. While the Jewish texts were not on the cutting edge of scientific discovery, they find a meaningful place in the history of science, between Babylonia and Egypt, in the time period between Hipparchus and Ptolemy. The book uses recent advances in method to examine the contacts and networks of Jewish scholars in their ancient setting. Second, the essays here tackle the problematic concept of a national scientific tradition. Although science is nowadays often conceived as universal, the historiography of ancient Jewish sciences demonstrates the importance of seeing the development of science in a local context. The book explores the tension between the hegemony of central scientific traditions and local scientific enterprises, showing the relevance of ancient data to contemporary postcolonial historiography of science. Finally, philosophical questions of the demarcation of science are addressed in a way that can advance the discussion of related ancient materials. Online edition available as part of the NYU Library's Ancient World Digital Library and in partnership with the Institute for the Study of the Ancient World (ISAW).