This book explores the life and thought of one of the most important but least known figures in early Zionism, Nathan Birnbaum. Now remembered mainly for his coinage of the word "Zionism," Birnbaum was a towering figure in early Jewish nationalism. Because of his unusual intellectual trajectory, however, he has been written out of Jewish history. In the middle of his life, in the depth of World War I, Birnbaum left his venerable position as a secular Jewish nationalist for religious Orthodoxy, an unheard of decision in his time. To the dismay of his former colleagues, he adopted a life of...