Theologie in der jemenitischen Zaydiyya: Die naturphilosophischen Überlegungen des al-Ḥasan ar-Raṣṣāṣ (Theology among the Yemeni Zaydiyya: The natural-philosophical reflections of al-Ḥasan ar-Raṣṣāṣ) by Jan Thiele (review)

It is something of a moot point whether the thought of the various rationalist strands of Islamic theology can be grouped sensibly under the rubric ‘philosophy’ together with that of figures, such as Avicenna and Averroes, who sit within the tradition known in Arabic as falsafa, which responded directly and explicitly to the Hellenistic philosophical heritage. ¹That the theological schools took positions on topics of properly philosophical concern (and therefore that studies dealing with them merit reviews in a journal of comparative philosophy) is less controversial. The formulation of Jan Thiele’s title, Theologie in der jemenitischen Zaydiyya: Die naturphilosophischen Überlegungen des al-Ḥasan ar-Raṣṣāṣ(hereafter, TjZ), loosely “Theology among the Yemeni Zaydiyya: The Natural-philosophical Reflections of al-Ḥasan arRaṣṣāṣ,” gestures at the distinction.

To provide some background, from the ninth century onward, the Zaydiyya, one of the three main branches of the Shi‘a, began to adopt the theology of the Mu‘tazila, the most rationalistic of the major Islamic theological schools. The two largest Zaydī communities of the day, one located around the southern shore of the Caspian Sea and the other in the mountains of northern Yemen, nevertheless followed distinct intellectual trajectories, particularly in regard to natural philosophy.

The Caspians fostered the teachings of the school of the Basrian Mu‘tazila known as the Bahshamiyya (p. 4). They advocated an atomist ontology, which held, roughly, that the world consists in a number of discrete, indivisible, identical particles, and in ‘accidents’ inhering in the particles (such as color, taste, location, and life), both of which present ‘attributes’ and ‘properties’ (in some or other relationship) by which they are perceived. This was accompanied by a quasi-occasionalist account of causality, considering that God, in the widest sense, and man, in a restricted sense, are the only real causal agents; all ‘natural’ events in the world (whatever other causal-type or quasi-causal-type relationships they may exhibit) are directly caused by God.

In Yemen, on the other hand, a group called the Muṭarrifiyya tended toward the doctrines of the Baghdadi Mu‘tazila, but, significantly, developed their own natural philosophy, according to which God had created the world from three or four ‘elements,’ and which admitted the causal efficacy of objects in the natural world (p. 6).

Following the political unification of the Yemeni and Caspian branches of the Zaydiyya in the early twelfth century, later accompanied by an attempt to harmonize the two intellectual traditions, Bahshamī theology became increasingly influential in Yemen as well (pp. 6–7). In this context, Ḥusām ad-Dīn al-Ḥasan bin Muḥammad ar-Raṣṣāṣ (1152–1188) (hereafter, R) was one of the major proponents of the teachings of the Bahshamī school. Thiele claims that the goal of TjZis to present the biography, impact, and theology of R in a wider perspective, concentrating on the ontological and cosmological theories that were the focus of his work (p. 10).

TjZ, a reworking of Thiele’s doctoral dissertation, consists of 225 pages, divided into six chapters. Chapter 1 (pp. 1–11) provides a short history of Zaydī studies in Europe and the Middle East, introduces R, and sets out the goals of the book. Chapter 2 (pp. 13–57) attempts a reconstruction of R’s biography and presents an inventory of his writings—extant, inextant, and those falsely attributed to him. Chapter 3 (pp. 59–74) provides an overview of R’s basic ontology, before chapters 4 (pp. 75–115) and 5 (pp. 117–299) examine, respectively, his thinking on causality and his exploration of the question of the doctrine of attributes and properties. Finally, chapter 6 (pp. 201...