This monograph provides an examination of the philosophical school of Siyyid Muhammad Husiyn-i Tabatabai, commonly known as Allamih Tabatabai. It is the first study to elucidate his philosophy of religious language through the lens of David B. Burrell’s Wittgensteinian/grammatical Thomistic philosophy. After outlining his life, career, oeuvre, and outreach, the monograph reveals a grammatical orientation in his work, evidenced by his concept of ‘focal meaning’, his idea of itibariyyat (‘mental constructs’), and his via media proposal that mediates between affirmative and negative theology, between divine transcendence and immanence, and, eventually, between a wholly other reality and the limits of human knowledge and language. The author’s innovative reading of Tabatabai aims to bridge Islamic and Western philosophical traditions and lays the groundwork for a new comparative agenda for the philosophy of religion. The methodological approach elucidates and applies concepts such as depth-grammar versus surface-grammar (a Wittgensteinian distinction), analogy, metaphor, and literal language. This work will appeal to scholars, students and general readers interested not only in Tabatabai’s thought but also in the philosophy of religion and related areas such as intercultural philosophy, interfaith relations, and the role of language in the study of traditions.