Ibn Taymiyya is commonly characterized as a fundamentalist advocate of "sola scriptura" despite the findings of new research which demonstrate his participation in the "Avicennan-turn" of post-classical Islamic thought. The text, edited and published here in Arabic and English for the first time as The Defense of Ibn Taymiyya, is an important record of how, just a few decades after Ibn Taymiyya's death, he was accused of Avicennism and defended from that accusation by one of his last living disciples. Ibn Qadi al-Jabal's Defense shows the reader another side of Ibn Taymiyya's thought, fully articulate in the metaphysics of post-classical Islamic philosophy, and suing for respectability within its intellectual circles. It is a scholarly apologia with a literary flair, making vivid reference to personal tutelage under Ibn Taymiyya himself, citing literary documents for his distinct theological theses while observing Mamluk conventions of respectability. Among its findings is the importance of Fakhr al-Din al-Razi and his interpreters for establishing Ibn Taymiyya's intellectual horizons, as this publication aims to both provoke and answer enduring questions about Ibn Taymiyya's status in the history of Islamic theology and philosophy.