 Sadr al-Din Muhammad b. Ibrahim b. Yahya Qawami Shirazi (ca. 1571–1636) is arguably the most significant Islamic philosopher after Avicenna. Best known as Mulla Sadra, he was later given the title of Sadr al-Muta’allihin (Master of the theosists) for his approach to philosophy that combined an interest in theology and drew upon insights from mystical intuition. He considered philosophy to be a set of spiritual exercises and a process of theosis, a pursuit of wisdom whose goal was to acquire wisdom and become a sage, and hence become godlike. He championed a radical philosophical method that attempted to transcend the simple dichotomy between a discursive, ratiocinative mode of reasoning and knowing, and a more intuitive, poetic and non-propositional mode of knowledge. He became famous as the thinker who revolutionized the doctrine of existence in Islamic metaphysics. By critiquing an Aristotelian metaphysics which assumed that the basic stuff of reality was constituted by substances, he initiated a (Neoplatonic) process metaphysics of change, founded upon and moved by acts of being. A keen thinker who wrote works in philosophy, theology, mysticism, and scriptural exegesis, he attempted a wide-ranging synthesis of approaches to Islamic thought and argued for the necessity of the method of understanding reality through a mixture of logical reasoning, spiritual inspiration, and a deep meditation upon the key scriptural sources of the Twelver Shi‘i tradition in Islam. Having a holistic approach to philosophical inquiry, his understanding of the pursuit of wisdom included scriptural hermeneutics and exegesis as well as theological reasoning. A key figure of a group of thinkers whom Nasr and Corbin referred to as the “School of Isfahan”, he played a major role in intellectual life during the revitalization of philosophy under the Safavid Shah ‘Abbas I (r. 996–1038 AH/1588–1629 CE) and later on in life was the most important teacher at the philosophical seminary known as Madrasa-yi Khan in his hometown of Shiraz. Since the early 19th century, the thought of Mulla Sadra has become the dominant philosophical paradigm in the Shi‘i seminary in the Islamic East and was also widely influential in South Asia.