Saint Thomas Aquinas: Philosophy, Theology, and Existence of God

Relations Between Reason and Faith

Saint Thomas Aquinas argued for the unity of truth, asserting that both reason (derived from sensory data) and faith (based on divine revelation) offer independent paths to understanding. While truths of faith are accepted without question, truths of reason (philosophy) can be explored through human intellect. Some truths of faith can be demonstrated rationally, such as the preambles of faith. Reason, faith, and theology converge, with theology illuminating natural theological truths. Philosophy and reason are erroneous only when their conclusions contradict faith.

Demonstration of the Existence of God

While accepting God's existence as revealed by faith, Aquinas offered five proofs based on sensory experience:

1. Motion/Change: All movement stems from an initial unmoved mover (God).
2. Efficient Causality: Every effect has a cause, leading to a First Cause (God).
3. Contingency: Contingent beings rely on a necessary being (God).
4. Degrees of Perfection: Varying degrees of perfection point to an infinitely perfect being (God).
5. Order and Cosmic Design: The order and purpose in the world suggest a first intelligent designer (God).

Creation of the World

Aquinas distinguished between essence (potentiality) and existence (actuality). In God, essence and existence are identical, signifying necessary and perfect existence. Other beings are contingent, their existence not inherent in their essence, but created by God.

Theory of Knowledge and Anthropology

Aquinas viewed humans as a composite of body (material) and rational soul (form). Knowledge acquisition involves an abstraction process where the soul extracts forms from sensory data, utilizing memory, senses, and agent intellect.

Ethics and Politics

Human actions aim towards happiness, the ultimate good achievable through the rational soul. Knowledge of God is the highest aspiration. God's eternal law governs the world, reflected in natural law, which guides human conduct through inherent inclinations. Positive law should derive from natural law, promoting the common good. The political order must be subordinate to the moral and divine order.