A ramshackle lodge on one of Istanbul’s seven hills plays host to the amorous adventures of a Sufi master. Cloistered in mansions along the Bosphorus, female devotees from the upper echelon of Ottoman society flock to his lodge in order to escape the monotony of their family lives. The charismatic shaykh seduces them, they fall desperately in love with him and give their fortunes to support his lodge. When the guide has satisfied himself and exhausted the available financial resources, he moves on and the cycle begins anew. The scenario from the late Ottoman novel Nur Baba brings to mind stories of wayward priests, gurus, and shamans who misuse their posts to gain sexual gratification and material gain. Such images played an influential role in shaping how many intellectuals in the Middle East thought about the institutions and rituals of Sufism in the early twentieth century. In contrast to the now popular images of Sufis as peace-loving, ecumenical Muslims, important intellectuals in the early twentieth-century saw Sufi institutions and practices as detrimental to society and deeply at odds with modern notions of progress, justice and equality. In order to better understand such critiques of Sufism, this paper takes a deeper look at a piece of anti-Sufi literature and assesses responses to it in the late Ottoman public sphere. The Turkish novel Nur Baba (1922) by Yakup Kadri Karaosmano?lu (1889-1974) presents an unflattering yet complex appraisal of a Bektashi lodge on the Asian shore of the Bosphorus. Some contend that Karaosmano?lu’s book influenced the decision of Mustafa Kemal Atatürk and the Turkish Parliament to abolish Sufism in the early years of the Turkish Republic. Beyond the simple consideration of being pro or anti Sufi, the novel reveals insights about the shifting terrain of late Ottoman intellectual and religious landscapes and helps us understand the anatomy of what some intellectuals considered the dark side of Sufism. I argue that the book builds its critique based not on anti-religious or even anti-Sufi grounds but rather on questions of gender, class and a notion of rational religion. Using a variety of materials from the late Ottoman press and the first-ever Turkish motion picture which is based on the book, I demonstrate that Nur Baba offers a unique window onto early twentieth century intellectual history and contributed to a debate on the nature of appropriate religion that had far reaching effects in modern Turkey.