The five daily prayers (ṣalāt) that constitute the second pillar of Islam deeply pervade the everyday life of observant Muslims. Until now, however, no general study has analyzed the rules governing ṣalāt, the historical dimensions of its practice, and the rich variety of ways that it has been interpreted within the Islamic tradition. Marion Holmes Katz's richly textured book offers a broad historical survey of the rules, values, and interpretations relating to ṣalāt. This innovative study on the subject examines the different ways in which prayer has been understood in Islamic law, Sufi mysticism, and Islamic philosophy. Katz's book also goes beyond the spiritual realm to analyze the political dimensions of prayer, including scholars' concerns about the righteousness and piety of rulers. The last chapter raises significant issues around gender roles, including the question of women's participating in and leading public worship. Katz persuasively describes ṣalāt as both an egalitarian practice and one that can lead to extraordinary religious experience and spiritual distinction. This book will resonate with students of Islamic history and comparative religion.