This fine biography focuses not only on the emergence of Kaplan's unique thought and approach to Judaism but on the larger thought-world of American orthodoxy from which his thinking emerged and with which it stood in continuing debate. The resultant study not only lays bare Kaplan's mind and personality but, equally important, reveals much about the nature of American Orthodoxy.

Jeffrey S. Gurock, Libby M. Klaperman Professor of Jewish History at Yeshiva University, is the author of When Harlem Was Jewish, 1870-1930 and The Men and Women of Yeshiva, both published by Columbia.Jacob J. Schacter is rabbi of the Jewish Center in New York City. Editor of the The Torah u-Madda Journal and Jewish Tradition and the Nontraditional Jew, he is also an author of numerous articles on early modern and contemporary Jewish life.