Rabbi Israel Salanter was arguably the most influential leader of nineteenth century non-Hasidic Orthodox Judaism. This book is a carefully researched biography and a detailed analysis of his thought and his religious-ethical program to revitalize Judaism. Salanter was a renowned Talmudic genius who, troubled by the breakdown of Orthodox Judaism in nineteenth century Eastern Europe, sought to reform the Jewish world from which he emerged. He introduced an ethical curriculum to fight corruption, spiritual malaise and non-religious forces, a program that still retains impact today. However, these reform measures were initially met with great resistance from the very rabbinic elite of which he was a respected member. Rabbi Israel fought the battle for Musar, as his innovations were called, by founding Talmudic academies and preaching to the masses. His difficult ethical program grew successful as his disciples began founding their own academies and experimenting with derivative Musar methods. As Rabbi Israel's influence grew in Eastern Europe, he left his native lands and traveled to very disparate regions of Western Europe. This book, an adaptation of the author's doctoral dissertation and originally published in 1953, follows Rabbi Israel's life through his travels and documents the successes of his students in his absence. Biographies of some of his most important disciples, such as Rabbi Isaac Blaser, Rabbi Jacob Joseph and Rabbi Joseph Yoizel Horowitz, complete the book's portrayal of Rabbi Israel's lasting legacy.