Abstract

This article explores Thomas Aquinas’ concept of causality, as well as his rejection of Democritus’ materialist view — which proposes a linear and mechanical chain of events. Aquinas’ proposal of a hierarchical causality, where all secondary causes depend on the First Cause or God, is also exposed. For Aquinas, causality is not a blind sequence of events, but a dynamic network of ordered interactions. Each being acts within an ontological hierarchy, where there is a first cause that continually sustains the order and existence of the universe. Aquinas distinguishes various degrees of causal autonomy among beings. A stone, with purely passive causality, responds to external forces according to the laws of physics, while an animal, such as a cat, exhibits greater autonomy, guided by its soul that gives it a center of action. The cat’s behavior is more unpredictable than that of the stone, since it is determined by its intrinsic nature. At the top of this hierarchy is the human being. Endowed with reason and will, the human being represents the highest expression of causal autonomy among composite beings. Humans do not act solely by instinct, but have the capacity to deliberate on good and evil and shape their lives based on freely chosen values. This freedom is not absolute, since the human, as a secondary cause, also acts under the design of the First Cause and consciously collaborates with the divine purpose. Causality in Thomas Aquinas is therefore more than a natural explanation of events; it is an ontological relationship that unites all beings with the divine order, with God as the First Cause and source of all being and movement. Humans uniquely integrate matter and spirit in the cosmos and possess a rational and moral capacity that distinguishes them from other living beings. This autonomy allows them to consciously participate in the divine plan and transcend material causality, a view that can be enriched by quantum superposition, which suggests that a being's potential (or capacity to be) is actualized by form, analogous to the actualization process that occurs in the universe according to divine order. Finally, Thomistic philosophy differs from pantheism in asserting that the universe, although unified, does not have an intrinsic self- sufficient purpose, since it depends on the creative will of God. There is an ontological distinction between Creator and creation.