Biblical Inspiration & Islamic Instrumental Causality: Thomas Aquinas on prophecy and the two authors of Sacred Scripture

Scripture, according to the Christian tradition, has two authors: God as the principal author and the Holy Fathers as instrumental authors. Thomas’s biblical inspiration is accomplished through instrumental causality—the theory of causal motion where the power of a principal agent works hiddenly through a lower cause to achieve an end beyond the lower cause’s natural powers. However, Thomas formulates a new account of instrumental causality by integrating Islamic causal accounts within Greek and Christian ones. After confirming that Thomas accounts for biblical inspiration with instrumental causality, I will show how Thomas’s Commentary on the Sentences of Peter Lombard explains his theory of instrumental causality pertaining to the sacraments and how it neatly fits biblical inspiration. Finally, I will demonstrate that Thomas’s formulation of instrumental causality is novel incorporating Islamic influences through Arabic sources including: the Arabic Liber de Causis, Averroes’s two sources of motion, and Avicenna’s modes of efficient causation. The paper will thereby conclude that Thomas’s explanation on how Scripture comes to be is beholden to philosophical thinkers of the Arabic tradition.