St. Thomas Aquinas: Reconciling Faith and Reason
Life and Work: Reason and Faith
St. Thomas Aquinas argues that truth is singular but can be understood through two distinct paths: reason and faith. Reason draws from sensory data, while faith is based on divine revelation. Both are independent yet complementary. Truths of faith, studied by theology, surpass human reason and must be accepted as divine emanations. Conversely, truths of reason, explored in philosophy, are accessible and demonstrable through the human mind. Some truths, like immortality and creation, are demonstrable by reason but also revealed by God, merging faith and reason. Theology employs reason to understand truth (natural theology). Philosophy serves theology, and since truth is one, any philosophical or rational conclusion contradicting faith is deemed incorrect.
Essence and Existence
To address creation, Aquinas distinguishes between essence (the nature of a being as potentiality) and existence (its actuality). In God, essence and existence are inseparable; His nature implies existence. Other beings are contingent; their essence doesn’t necessitate existence. They gain existence through God’s creative act. Essence represents the potential for being, while existence actualizes it.
The Existence of God
God’s existence is a foundational revelation. However, since human knowledge begins with the senses, God’s existence isn’t self-evident and requires rational demonstration, derived from observing creation. Aquinas presents five ways:
- 1st Way: The Argument from Motion: Based on Aristotle, this cosmological proof observes that everything in motion is moved by another. This chain of movers cannot be infinite, necessitating a First Mover, unmoved by anything else – God.
- 2nd Way: The Argument from Efficient Causality: Also from Aristotle, this argument posits that everything has an efficient cause distinct from itself. This causal chain cannot be infinite, requiring a First Cause (uncaused cause) – God.
- 3rd Way: The Argument from Contingency: Contingent beings exist but can cease to exist, implying a time when nothing existed. Their existence necessitates a Necessary Being, whose existence is not contingent – God. Inspired by Maimonides.
- 4th Way: The Argument from Degrees of Perfection: Beings exhibit varying degrees of perfection (goodness, truth, etc.). These degrees imply an absolutely perfect being as the ultimate standard and cause of all perfections – God. Inspired by Plato and Aristotle.
- 5th Way: The Argument from Design (Teleological Argument): The universe displays order and purpose, even in non-intelligent beings. This implies an intelligent being directing all things toward an end – God.
Anthropology
Aquinas asserts the soul’s immateriality and intellect. In humans, the intellect is united with a material body, a concept known as hylemorphism. This union dictates that knowledge begins with sensory perception. The intellect abstracts universal concepts from particular sensory data. This abstraction bridges the gap between individual perceptions and universal concepts. Sensory perceptions leave “phantasms” in memory, which the intellect uses to form universal concepts. The intellect knows individual beings indirectly by recognizing them within the abstracted universal concept.
Ethics
Aquinas’s ethics is theocentric. Human actions aim at an ultimate end: happiness, achieved through the rational soul’s exercise (knowledge and virtue). Since God is the supreme good, a life dedicated to knowing God is the most perfect and happy. God’s law for the universe is the eternal law. However, humans, unlike other beings, are free and guided by moral law, not just physical laws. The part of eternal law pertaining to humans is natural law (universal, clear, immutable), a set of moral standards based on human nature. Humans can discern their inclinations and deduce rules of conduct. These inclinations include “substance,” “rationality” (knowing truth and living in society), and social living, regulated by legal rules. Positive law must align with human nature and aim for the common good.
Politics
The state’s ultimate goal is the common good, achieved through positive law. This includes peace, morality, and necessary goods. The common good justifies civil authority. Unjust laws, those not serving these objectives, do not bind citizens as they contradict natural law.