Five Rational Proofs for God's Existence

Reason and Faith in Aquinas

B: Since Thomas was convinced that faith and reason are harmonized and complementary, he argued that some truths of faith are accessible to reason. For example, we can come to the knowledge of God using only the light of reason. This aligns with what Thomas termed "rational or natural theology." He first proposed a question, then provided opposing arguments. Next, Thomas presented his argument, serving as his defense. In the body of the article, he offers his solution, in this case, the five ways. Finally, he concludes by responding to the opposing arguments. Thomas solved the problem of the relationship between reason and faith, stating that there are two kinds of theology: natural and supernatural. Natural theology is based on reason, while supernatural theology is based on divine revelation and presupposes faith. The five ways are examples of natural theology: proving God's existence using reason alone. These are rational ways to know God's existence. St. Thomas outlines five ways: 1) motion, 2) efficient causes, 3) contingency, 4) degrees of perfection, and 5) teleology.

Aquinas' Five Ways

C:

1. The Argument from Motion

The senses tell us that things are moving. Whatever moves is moved by another. This chain cannot proceed infinitely. There must be a prime mover, unmoved by anything, which we call God.

2. The Argument from Efficient Causes

In the world, there is an order of efficient causes. Nothing can cause itself, as it would precede itself, which is impossible. This chain cannot proceed infinitely. There must be a first efficient cause, which we call God.

3. The Argument from Contingency

Things exist and cease to exist; they are contingent. If everything were contingent, there would have been nothing at some point. Since something exists now, there must be a necessary being, which we call God.

4. The Argument from Degrees of Perfection

We find things more or less good, true, or noble. These degrees imply a maximum, a being that is the cause of all goodness, truth, and nobility. This being we call God.

5. The Argument from Design

We see things in nature acting with purpose. Things without awareness cannot tend towards an end unless directed by an intelligent being. This intelligent being, who directs all natural things, we call God.