Eugen Rosenstock-Huessy, a Christian convert and a social philosophy scholar, had an intense conversation with the Jewish thinker Franz Rosenzweig in 1913. This "Leipzig Conversation" shattered Rosenzweig's understanding of the meaning of religion, but it also propelled him to embrace his innate Jewish faith. Three years later, they engaged in a correspondence that has emerged as an historic, stunning dialogue on Jewish-Christian thinking. Rosenzweig went on to write The Star of Redemption, a classic work of modern Jewish philosophical theology and to become one of the most important and influential figures of twentieth-century German Jewry. Rosenstock-Huessy took a different path—writing his Sociology, which pointed the social sciences in a new direction based on speech-thinking, and an enormous, rich body of work covering grammar and society, revolutions, Church history, and industrial law; teaching generations of European and American university students; and putting his faith into action. This is the first major collection of essays on these two close friends' "new thinking." Their dialogue mirrored Nietzsche's anti-transcendent reading of Judaism and Christianity, as well as his attack on idealism. But their dialogue also resurrected the redemptive cores of these faiths as sources for the rejuvenation of human society. This book brings to publication three essays by Rosenstock-Huessy on Nietzsche, and a translation of a chapter from his Sociology, clarifying the post-Nietzschean approach of the "new thinking." The Cross and the Star, a 50-year span of significant scholarship, vivifies the reasons for Rosenzweig's and Rosenstock-Huessy's influence on faith and society, and why their respective thought speaks directly and enduringly to the global human challenges of our time.