Determinism, regularity and contingency: Thomas Aquinas and the assimilation of Aristotelianism regarding the autonomous order of nature

Abstract

This article studies the assimilation, in the cosmology of Thomas Aquinas, of the necessitarianism of Aristotle’s physics. It analyzes the rejection of determinism by Aquinas regarding the mode of action of the first principle, and his acceptance of the Aristotelian theory of natural regularity and necessary causal concatenation of second agents as a sufficient explanation of physical dynamism. It also highlights Aquinas’ defense of the autonomous character of nature with regard to its procedural aspects, as it is capable of self-preservation due to the formal structure with which it has been created, and his limitation of divine intervention and tutelage regarding the maintenance of the physical order.

Keywords: Thomas Aquinas, Aristotle, medieval physics, determinism, voluntarism, 13th century.