This book illuminates important issues faced by Orthodox Judaism in the modern era by relating the life and times of Rabbi Yudel Rosenberg (1859–1935). In presenting Yudel Rosenberg’s rabbinic activities, this book aims to show that Jewish Orthodoxy could serve as an agent of modernity no less than its opponents. Yudel Rosenberg’s considerable literary output will demonstrate that the line between “secular” and “traditional” literature was not always sharp and distinct. Rabbi Rosenberg’s kabbalistic works will shed light on the revival of kabbala study in the twentieth century. Yudel Rosenberg’s career in Canada will serve as a counter-example to the often-expressed idea that Hasidism exercised no significant influence on the development of American Judaism at the turn of the twentieth century.