In this introductory, yet comprehensive book, Eric Geoffroy explains that Sufism is the inner dimension of Islam and has its source in the Koran and in the life and sayings of the Prophet Muhammad. Geoffroy discusses how Sufism was formed and how great masters have adapted its initiatic doctrines and practices to changing conditions within the Muslim world. Surveying the history of Sufism, this book covers its earliest days up until our own times and addresses Sufism's uneasy relationship with various forms of fundamentalism. Replete with many sayings from various Sufis throughout the ages, including Ibn Arabi, Rumi, Hallaj, and Ghazali, this book uniquely presents Sufism "as it is lived" by highlighting the importance of the spiritual master, the method, rites and conduct in daily life, as well as the role of the feminine in Sufism. This is Dr. Geoffroy's first book to be translated into English in its entirety.