First paragraph: Ḥārith ibn Asad al-Muḥāsibī (d. 243/857) has not been the subject of a comprehensive study for half a century; the present book therefore arouses high expectations. The question of where to situate al- Muḥāsibī in the intellectual history of the third/ninth century is anything but settled; a new approach might be in order. But the reader is ultimately disappointed. The author has delved deeply into al- Muḥāsibī’s works, but he presents the results of his investigation in a rather apodictic way and largely omits engaging in a dialogue with previous research.