The first chapter focuses on early Muʿtazilite and Ashʿarite theologians. It examines the birth and development of Ashʿarite occasionalism as a response to the Muʿtazilite theological project which aims to preserve the intelligibility of the world and God and, to this end, is ready to accept the idea of necessity in the world and, even, in God. The modus operandi of Ashʿarite theological project in this context remains to preserve the divine will and freedom. This, then, leads to construction of, what I call, a theology of possibility. It is within the larger context of this debate that occasionalist theory of causality emerges as the cornerstone of Ashʿarite theology of possibility. The chapter starts with an examination of early Ashʿarite and Muʿtazilite discussions about the relationship of the divine attributes to God. It then shows how these discussions led to the emergence of Ashʿarite occasionalism. Finally, it explores how the occasionalist perspective provided the basis for Ashʿarite convictions on other important cosmological and theological discussions.

The tenth chapter focuses on a contemporary approach to causality. Here, I offer a detailed survey of Said Nursi’s account of causality. Nursi’s neo-occasionalism makes original contributions to Ashʿarite occasionalist metaphysics of causation while integrating it with Ibn ‘Arabī’s theory of Divine Self-Disclosure. As such, his theory of causality suggests an interesting meeting point of kalām and Sufi metaphysics. He also defends and emphasizes the idea of disproportionality of cause and effect in an unprecedented way in the history of Islamic occasionalism. The chapter also analyzes Nursi’s treatment of free will and theodicy.

The eighth chapter focuses on the thought of Jurjānī to understand later developments in the occasionalist tradition. Jurjānī was one of the most important Ashʿarite theologians who transformed occasionalism from a theory of causality into the central axis of all theological thinking. The notion of possibility made central by Ashʿarite occasionalism became the modus operandi for thinking about questions from prophetology and eschatology to theodicy and free will. More importantly, Jurjānī develops a critical philosophy of science to appropriate and criticize Aristotelian-Ptolemaic-Avicennian natural philosophy/sciences. An examination of this attempt reveals the complex relationship of Ashʿarite occasionalism with medieval natural philosophy and sciences.

The third chapter introduces Ghazālī’s and Rāzī’s responses to Ibn Sīnā’s theological and cosmological challenges to the occasionalist worldview. Ghazālī’s response is heavily influenced by Ashʿarite theology’s emphasis on the divine will and freedom. In this discussion, Ghazālī harkens back to the earlier Ashʿarite tradition, offers novel applications of old arguments, and raises important challenges to Ibn Sīnā. Rāzī, on the other hand, formulates a list of arguments for the defense of Ashʿarite cosmology based on a discrete and atomistic model of the universe. Rāzī’s atomistic arguments can be seen as a novel development in the occasionalist tradition. Rāzī’s use of Euclidian geometry for and against atomism also led to emergence of an occasionalist philosophy of science marked by pragmatic and sceptic attitude towards dominant scientific models.