Nigal's thorough and provocative analysis of magical practices in Judaism offers the reader a startling array of data and discourse on the methods of practical mysticism from rabbinical times to the twentieth century.

The book is essentially divided into two parts. The first (chapters 1‒4) traces the history of Ba'alei shem, or wonder-workers, kefitsat ha derekh, gilgul (transmigration of souls—metempsychosis), dybbuks (souls of the dead), and exorcism. Nigal writes as a historian of ideas, mapping the changing formulations of similar ideas across historical and ideological boundaries. In the second part Nigal writes as a folklorist, comparing and contrasting stories as they develop from pre-hasidic literature to the hasidic story, and as they move between Christianity and Judaism. In his introduction, Nigal presents his overarching thesis regarding the hasidic story: ‘There is nothing new, because everything was already present in previous stories. The innovation in the hasidic story consisted of the recomposition of these elements and their appearance in new situations’ (p. xiii). Yet later on he states: ‘All that changed in the hasidic story is that the active central figure is no longer the early baal shem but the Baal Shem Tov, or a hasidic tzadik’ (pp. 170‒1). This later definition reflects his theory regarding the uniqueness of magical practices in hasidism. ‘Beginning with the Baal Shem Tov, the hasidic story contained the idea that the tzadik sees from afar, knows from afar everything that happens, and is even capable of acting from a distance, facts that presumably cancel the need for kefitzat ha-derekh’ (p. 48). This distinction is not only historical in nature, according to Nigal, but emerges as a difference between stories and practices of non-hasidic wonder-workers such as Rabbi Jonathan Eybeschuetz, who was a contemporary of the early hasidic tsadikim, and the hasidic masters after the Ba'al Shem Tov. The hasidic master is not merely a wonder-worker or adept in the recitation of magical formulas, but a man with superhuman powers whose proficiency affects the way the hasidic story develops (see e.g. p. 214).