What is God? Understanding the Four Causes

Part 2: What Is a Cause? Understanding the Four Causes

To ask What is God? is not like asking What is a cloud? or What is gravity? God is not just one being among many, a bigger part of the universe. He is something more foundational: the cause of all that exists. But what do we mean by cause?

Before we can think clearly about God, we need to think clearly about causality. Fortunately, St. Thomas Aquinas gives us a rich framework to do just that, building on the work of Aristotle, who first explored the question deeply.

What Is a Cause?

In everyday speech, a cause is just “what made something happen.” But in classical philosophy, the concept is much more refined. According to Aristotle, and adopted and developed by Aquinas, there are four causes that explain why a thing is the way it is.

These four causes are not competing explanations. They are four different dimensions of explanation that work together.

Let’s take a simple example: a table.

	Table	Statue
Material Cause	The wood it is made of	The bronze or marble used
Formal Cause	The design or structure	The shape of the figure
Efficient Cause	The carpenter	The sculptor
Final Cause	To serve meals	To honor someone or something

These four causes can be summed up like this:

1. Material – What something is made of

2. Formal – What makes it the kind of thing it is

3. Efficient – What brought it into being

4. Final – The purpose or goal for which it exists

In the case of a statue, the bronze is shaped (material) according to a form (design), by the hands of a sculptor (efficient), for the sake of remembering someone (final).

Why This Matters for Talking About God

You might be wondering—what does this have to do with theology?

Everything.

If we say that God is the cause of all things, we need to ask what kind of cause we mean. In fact, Aquinas will argue that God is the First Cause in all four senses, but especially as the First Efficient Cause and the Ultimate Final Cause.

God as the First Efficient Cause

Aquinas teaches that God is the first efficient cause. That is, He is the One who brings all things into being. He doesn't do this at the beginning of time only, but in every moment.

Nothing causes itself. Everything that begins to exist must be caused by something else. But this can’t go on forever. There must be a first cause, not dependent on anything else. That cause is God.

This is not a “God of the gaps.” Aquinas is not saying we invoke God when we run out of scientific explanations. He’s saying that even if we understood every physical process in the universe, those processes themselves would still need a cause. God causes not just the beginning, but the very act of being.

God as the Final Cause of Everything

Even more profoundly, Aquinas says that God is also the final cause of all things. That is, everything is ultimately ordered toward Him.

Why does the sculptor carve the statue? To remember someone. Why does the universe exist? To glorify God. And not in a self-centered way, but in the way a beautiful piece of music glorifies its composer. All creation exists to reflect and share in the goodness of God.

As Aristotle said,

“The end is the first cause in the order of intention, but the last in the order of execution.”

In simpler terms: the purpose comes first in the mind, even if it comes last in reality. God creates with a purpose, and that purpose is Himself.

What Makes God Different

Of course, we must be careful. God is not just another efficient cause like a carpenter or a sculptor. He is not one more part of the chain. He is the source of the chain itself.

And unlike material causes, God is not made of anything. He is not a composite. He does not have parts. He is pure actuality- something we will explore more deeply later.

But the language of causality still helps us. It gives us a way to think, not about what God is made of, but about what it means for Him to be the source of all that exists.

The Power of Finality

Modern science often neglects final causes. We ask how things work, but not why they exist. Aquinas reminds us that purpose is not an afterthought. It is fundamental.

To be human is to seek purpose. And to ask “What is God?” is to ask the ultimate question of purpose.

If God is the first cause, then He is not only our origin. He is our end.

Coming Next: How Do We Talk About God?

We’ve begun to understand that God is the cause of all things. But how can we speak about God without reducing Him to creaturely categories?

In Part 3, we’ll explore the language of analogy, the dangers of speaking too little or too much about the divine, and why saying “God is good” means something far deeper than we usually imagine.