Islamic discussions on causality are frequently related to two main philosophical issues, namely, the nature of God as the causal agent par excellence and the creation or origination of the world. Islamic theologians and philosophers both built their different conceptions of causality upon Greek sources, mainly Neoplatonic—such as the Arabic version of the Liber de causis (Taylor 2012), some texts derived from Plotinus’s Enneads known as the Plotiniana arabica (d’Ancona 2010), and some Neoplatonic commentators on Aristotle’s works (Wisnovsky 2002). From the Neoplatonic sources, metaphysicians such as al-Kindı-, al-Farabı-, and Ibn Sına- developed the notion of primary causality which was essential to argue for the existence of a First Cause (al-‘illa al-u-la-) or God as responsible for the origination or creation of being (Taylor 2012). Nevertheless, the Aristotelian tradition was also quite influential: from Aristotle’s Physics and Metaphysics the Islamic tradition took the characterization of the four causes as something essential for their comprehension of the natural world and of the moving heavens. Aristotle’s conception of causality, however, was controversial for some theologians, mainly al-Ghazalı- and the Ash‘arites, given that it explained natural phenomena without appealing to the necessity of a creator.