Calling for a fundamental rethinking of modern Judaism, the author of this study focuses on the transformation of Jewish practice in response to the civil rights, economic possibilities, and social challenges which came with Emancipation. The text explores the central role of practice in Judaism, tracing five key phenomena which have crucially influenced Jewish practice over the past two centuries: politics; explanation of the commandments; nostalgia; the unending quest for authority; and appeals to the sanctity of tradition.