The Philosophy of St. Thomas Aquinas: Faith, Reason, and the Existence of God
The Epistemological Question of Knowing God
Can We Know God?
St. Thomas Aquinas addresses the question of whether it is possible to know God. He argues that the existence of contingent things in nature, things that may or may not be, points to a necessary being. Since something cannot come from nothing, these contingent things must originate from a pre-existing necessary being, which is what we call God. Aquinas views this as evidence for God’s existence. He defines contingent as that which exists but could not exist, and necessary as that which exists and could not be otherwise.
The Relationship Between Philosophy and Theology
The Confluence of Reason and Faith
For St. Thomas, philosophy and theology intersect. While philosophy relies on reason, it converges with the truths of faith. These truths, known as preambles of faith, include the existence of God as the creator of the world. Aquinas’s position can be summarized as follows:
- Reason and faith are distinct, differentiated by their content and methods.
- There is no contradiction between reason and faith.
- There is a zone of confluence between reason and faith.
Aquinas identifies three types of truths:
- Articles of faith (dogma): Truths accessible only through faith, such as the Trinity.
- Natural truths: Truths about the natural world, accessible through reason.
- Preambles of faith: Truths accessible through both faith and reason, such as the existence of God.
The Five Ways to Demonstrate God’s Existence
Aquinas presents five ways to demonstrate God’s existence through reason:
- Motion/Change: Everything that moves is moved by another. This chain of movers cannot be infinite, so there must be a first unmoved mover, which is God.
- Efficient Cause: Everything has a cause. This chain of causes cannot be infinite, so there must be a first uncaused cause, which is God.
- Contingency: Contingent beings could not exist if there was a time when nothing existed. Therefore, there must be a necessary being, which is God.
- Perfection: Beings are more or less good, true, and just based on their proximity to a perfect being, which is God.
- Teleology/Purpose: Natural bodies act for a purpose. This purpose is given by an intelligent being, which is God.
The Life and Work of St. Thomas Aquinas
From Aquino to Paris, Rome, Bologna, and Naples
Born in Aquino to a noble family, St. Thomas Aquinas studied at Monte Cassino, the University of Naples, and later in Cologne with Albert the Great. He became a Dominican friar and taught at the Universities of Paris, Rome, Bologna, and Naples. He died at the age of 50 en route to the Council of Lyons. His short life spanned a period of ideological and political-religious tensions in the Late Middle Ages.
The Christianization of Aristotle
Initially met with suspicion, Aquinas’s interest in Aristotle led him to develop a philosophical and theological system that reconciled Aristotelian thought with Christian theology. This synthesis, known as Thomism, aimed to demonstrate the compatibility of reason and faith. Aquinas argued that Aristotle’s philosophy, which posited a prime mover or God, could be used to support Christian beliefs. He believed that God reveals himself through both the Bible (revealed theology) and reason (natural theology). Aquinas saw Aristotle’s philosophy as a partial path to truth, limited by its lack of Christian revelation. His goal was to show that there is only one truth, accessible through both faith and reason.
The Role of Faith in Understanding
Does Faith Help or Hinder Reason?
Aquinas believed that faith enhances reason. Faith helps us understand the relationship between God and humanity, including the concept of the soul as a spiritual principle connected to the body. This understanding avoids Cartesian dualism and promotes a deeper understanding of ourselves. Faith, as a supernatural gift from God, can strengthen human intelligence and understanding.