The introduction presents Martin Buber’s early 20th century attempt to expose the existence of “Jewish mysticism,” and the later establishment of the academic study of Jewish mysticism by Geshom Scholem, and the revolution that occurred in the study of Jewish mysticsm in the 1980’s. The introduction outlines the genealogical study and critical examination of the concept and research field of Jewish mysticism that will be presented in the book, and explains that it seeks to expose the deep-rooted factors that have guided (and continue to guide) the identification of Kabbalah and Hasidism as mysticism, and how these influence the ways in which these movements are interpreted and studied. It discussed that two central claims that guide the discussion in this book. The first is that mysticism, in general, and Jewish mysticism, in particular, are not natural and universal phenomena that were discovered by researchers in the nineteenth and twentieth centuries. Rather, these are discursive constructs which served to catalogue, compare, and explain a broad range of cultural products and social structures not necessarily related to one another. The second claim that guides the discussion of the study of Jewish mysticism involves the theological assumptions that underpin the category of mysticism.