 The pivotal position of Avicenna in the history of Islamic philosophy emerges in all clarity if we consider that the three approaches to Aristotle’s Metaphysics considered here (classification, commentary, adaptation), as well as the main schools of thought of the formative period (the Kindian, on the one hand, and the Farabian-Baghdadian, on the other), ended or began to wither with the rise of Avicenna’s metaphysics. Although the text of Aristotle’s Metaphysics continued to circulate in Arabic after the eleventh century, the metaphysical works of Avicenna gradually superseded the Metaphysics as the text to be copied, commented upon, and evaluated (either favorably or critically), until Avicennism replaced Aristotelianism by incorporating it. Likewise, in the post-Avicennian tradition, issues regarding Avicenna’s distinction between essence and existence, and the primacy of the former over the latter, are widely debated, and the prerogatives of an Avicennian philosophical theology over Islamic dialectical theology, or kalām, to be the discipline more properly entitled to speak about God, hold pivotal importance.