The Thomistic Theological Synthesis of Islamic and Jewish Philosophy: Analysis of Aquinas’ Arguments Based on Direct References to Avicenna, Averroes, Maimonides and Avicebron in Summa Theologiæ

This study systematically identified and enumerated Aquinas’ direct references to the two most frequently quoted Islamic and Jewish philosophers, Avicenna, Averroes, Rabbi Moyses, and Avicebron, in Summa Theologiæ (ST), analyzed Aquinas’ argumentative responses to their philosophical positions, and based on Aquinas’ alignment or divergence with the cited and attributed philosophical thought, categorized them according to agreement, partial agreement/disagreement, and disagreement. Furthermore, the study compared these arguments vis-à-vis their locus in ST, Aquinas’ stance, and philosophical and denominational origins. This investigation introduced a novel data-driven methodology that integrated traditional textual and philosophical qualitative analyses with a structured quantitative assay and rigorous cross-examination of data, yielding precise qualitative and quantitative findings and filling the extant gap in Thomistic scholarship. The results demonstrated that Aquinas’ engagement with these philosophers was strategically selective. Aquinas’ direct reference-based arguments were most prevalent in ST I, followed by ST Supplement and ST I–II. Conversely, ST II–II and ST III featured minimal engagement. Avicenna and Averroes were the principal focus of Aquinas’ arguments, whereas Rabbi Moyses and, marginally, Avicebron received less attention. The correlational pattern identified herein originates in Aquinas’ realization of Aristotelian peripatetic philosophy and Abrahamic scriptural theology. Aquinas’ attainment of knowledge from divergent philosophical traditions represents a critical element of Thomistic theological synthesis, strengthening ST’s philosophically expansive yet doctrinally consistent character. Furthermore, it attests that Aquinas’ philosophical theology, as a scientific discipline, has matured in profoundly dynamic interactions with Islamic and Jewish traditions, remaining influential over the past 750 years since the composition of ST.