Mulla Sadra, also known as Ṣadr ad-Dīn Muḥammad Shīrāzī, was a prominent Persian philosopher, mystic, theologian, and scholar who lived in the 17th century. He played a pivotal role in the Iranian cultural renaissance during that period. As a leading figure of the Illuminationist school of Philosophy, he skillfully integrated various philosophical traditions from the Islamic Golden Age into what he termed “Transcendent Theosophy” or al-hikmah al-muta’āliyah. Mulla Sadra’s philosophical insights brought about a significant shift from essentialism to existentialism in Islamic philosophy, though his existentialism should not be equated with Western existentialism. His work ambitiously united Avicennism, Illuminationist philosophy, Sufi metaphysics, and the theology of the Ash’ari school within the framework of Twelver Shi’ism. His major work, “The Transcendent Philosophy of the Four Journeys of the Intellect,” provided a fresh perspective on Peripatetic philosophy and emphasized the idea of Unity of Existence.