The Zaddik. By Samuel H. Dresner. With a preface by Abraham J. Heschel. Abelard-Schuman. 30s. Heinrich Graetz, the famous Jewish historian, writing of the Chassidic movement, described it as “a daughter of darkness.” It was, says Graetz, “born in gloom, and even today proceeds stealthily on its mysterious way.” The majority of modern writers in…