Does God exist? How can we know? Well, according to Saint Thomas Aquinas, reason can explain everything; it can prove His existence.
I have known him since I was in college because he was one of the patron saints of our school, a Dominican institution.
But I learned about his contribution only when my professor in professional education asked us to simulate a panel discussion about him.
That was when I got to explore what he stood for. Let us talk about it.
Saint Thomas Aquinas Was a Dominican Priest
In 1244, Aquinas joined the Dominican Order, which is a Catholic community founded by Saint Dominic in the 13th century.
Saint Dominic was a Spanish priest who started the Dominican Order to preach truth through study and simple living.
As a Dominican priest, he spent much of his life teaching at universities, writing books, and debating with other scholars.
Doctor of the Church
The Catholic Church gave Aquinas the title “Doctor of the Church” in recognition of his profound contributions to theology and philosophy.
Only a few saints in history have received it. In fact, as of writing, only 38 saints have been officially recognized as Doctors of the Church.
Saint Thomas Aquinas Wrote Books on Theology and Philosophy
Aquinas wrote some of the most influential books in Christian history, including the Summa Theologica and the Summa Contra Gentiles.
The Summa Theologica is a massive collection of questions and answers about faith, covering everything from the existence of God to the nature of humans, morality, and even the role of angels.
On the other hand, the Summa Contra Gentiles was written for missionaries and was designed to explain Christianity to non-believers.
Saint Thomas Aquinas Believed That Reason Could Prove Religion
Aquinas said that certain truths about God can only be known through faith because they are mysteries.
But the basic fact of God’s existence can be proved by reason.
Founder of Thomism
Thomism was a system of thought that Aquinas developed to explain how faith and reason work together.
It was built upon Aristotle’s philosophy, which he thought was helpful for understanding the natural world.
Natural law says that some moral truths are built into human nature and can be known through reason.
Its key idea is that reason can lead us to certain truths about God, while faith gives us higher truths that reason alone can’t reach.
Saint Thomas Aquinas’ Five Ways to Prove God’s Existence
Aquinas came up with five logical arguments that try to prove God’s existence through reason, commonly known as the Five Ways.
Motion
Everything around us is constantly moving, but nothing moves on its own. Something has to start the motion.
If you trace it all back, there has to be a first mover, something, or someone, that set everything into motion without being moved itself.
Aquinas believed that the first mover is God.
Efficient Cause
Everything has a cause, like how a tree comes from a seed, and that seed came from another tree. Nothing just pops into existence on its own.
If you trace the chain of causes backward, you can’t go on to infinity because then there would be no first cause, and nothing would exist now.
So, there must be a first cause, something that didn’t need to be caused by anything else. Aquinas said it was God.
Possibility and Necessity
Many things in life come and go: People are born, live for a while, and die.
Everything seems to have a beginning and an end. That means our existence is possible, but not guaranteed.
Now, if everything were just possible, not necessary, then there could have been a time when nothing existed at all.
A person who believes in nothing is called a nihilist. Nihilists reject all meaning, values, or truth.
But if there was ever truly nothing, then nothing would exist now because something can’t come from nothing.
So, there must be at least one being that has to exist, something that doesn’t come and go. Aquinas said that this necessary being is God.
Gradation
We compare things by their qualities. When we do that, we measure them against some ultimate standard.
This standard must come from something that is perfectly good, true, and beautiful. He said that the perfect being is God.
Design
Even non-thinking things, like plants or planets, act in ways that seem directed toward a goal. This order can’t be by chance.
They can’t work toward a goal unless they are directed by something intelligent. Aquinas said this intelligent designer is God.
Saint Thomas Aquinas Developed Aristotle’s Natural Law
Aquinas developed Aristotle’s natural law, which is the belief that we are born with a sense of right and wrong.
For instance, we know that it is wrong to kill, not just because religion says so, but because reason tells us that it is harmful.
He believed that God created the world with order, and we have the ability to understand that order through our minds.
Using our reason is part of how we live out our purpose as human beings.
