The 13th-century Dominican friar and theologian whose Summa Theologiae attempted to synthesize Aristotelian philosophy with Christian doctrine — producing an intellectual framework that the Catholic Church declared its official philosophy in 1879 and that continues to underpin Catholic moral theology, natural law theory, and the philosophy of religion.
Aquinas died at 49, leaving the Summa Theologiae unfinished. His secretary asked him why he had stopped writing. He said: 'I cannot go on. All that I have written seems to me like straw compared to what I have seen.' The remark is reported; it may be apocryphal. What is not apocryphal is that a 13th-century friar's unfinished synthesis of Aristotle and Christian theology is still the official philosophy of the world's largest religious institution. The question of why ideas persist — and whose interests their persistence serves — is where reading Aquinas seriously begins.