St. Thomas Aquinas: Faith, Reason, Metaphysics, and Ethics
St. Thomas Aquinas
1. Relationship Between Faith and Reason
The Thomistic approach rejects the theory of double truth, upholding the unity of truth. Aquinas recasts this relationship from the Augustinian tradition, with three key aspects:
- Clear Distinction: Faith and reason are autonomous powers, each with its own field of knowledge and methods.
- Joint Ventures: Some truths are accessible through both faith and reason (preambles of faith or rational theology), while others are revealed through faith (revealed theology). Fideism alone is insufficient; some theological truths are reasonable, though not all humans can grasp them.
- Contradictions Impossible: True contradictions between faith and reason cannot exist. Faith serves as an external criterion to guide and correct reason, maintaining its autonomy without succumbing to Averroism. Reason, while subordinate to faith, is a vital faculty for understanding revealed truths.
2. Metaphysics
Aquinas’s philosophy reconciles Aristotelian thought with Christian doctrine. His metaphysics incorporates:
- Aristotelian Principles: Substance theory, hylomorphism, act and potency, and the four causes.
- Non-Aristotelian Principles:
- Essence-Existence Distinction: A fundamental concept. Essence defines what a thing is, while existence actualizes it. All beings except God possess both essence and existence. God’s essence is to exist, making Him ontologically superior and the necessary ground of reality.
- Principle of Participation: Creatures imitate God, the exemplary cause, deriving their existence and perfection from His absolute perfection.
- Principle of Exemplary Causality: Creatures are linked to God as their creator.
- Principle of the Degrees of Being: A hierarchical view of nature, where beings closer to God possess greater perfection.
3. Theology: The Five Ways
Aquinas offers five a posteriori arguments for God’s existence:
- First Way: The Unmoved Mover: Everything in motion is moved by something else, leading to an unmoved mover, God.
- Second Way: The Uncaused Cause: Every effect has a cause, leading to an uncaused cause, God.
- Third Way: Contingency and Necessity: Contingent beings require a necessary being, God, for their existence.
- Fourth Way: The Degrees of Perfection: Limited perfections point to a pure perfection, God, as the source of all being.
- Fifth Way: Teleological Argument (Design): The order and purpose in the world indicate an ordering intelligence, God.
4. Anthropology and Theory of Knowledge: Theory of Abstraction
Thomistic anthropology posits a substantial union of body and soul (immortal, created by God). The soul has various powers:
- Lower Powers: Shared with animals (appetitive and cognitive).
- Higher Powers: Unique to rational creatures (appetitive and cognitive, including understanding).
The soul is immortal, retaining its intellectual powers after separation from the body. Human knowledge has two levels:
- Empirical: Concrete and singular.
- Rational: Universal and common.
Aquinas’s theory of abstraction explains the transition from empirical to intellectual knowledge:
- The senses perceive specific forms.
- Memory retains concrete images.
- The agent intellect abstracts universal forms from particulars.
- The patient intellect forms concepts from these abstracted forms.
Understanding involves abstraction and generalization, starting with universal concepts and then applying them to concrete particulars.
5. Ethical and Political Thought
Thomistic ethics is teleological, aiming at happiness (beatitudo) through the development of human capacities. True happiness lies in knowing God, attainable fully in eternal life. Natural law guides humans toward this end, comprising three types:
- Eternal Law: God’s divine order governing all creation.
- Natural Law: Rational creatures’ participation in eternal law, based on human inclinations:
- Self-preservation.
- Procreation and family.
- Knowledge, truth, and social living.
- Positive Law: Human-made laws, subordinate to natural law, ensuring peaceful coexistence.
Aquinas’s political theory emphasizes the state’s role in facilitating human flourishing and achieving true happiness. The state must ensure that positive law aligns with natural law, reflecting God’s ultimate authority.