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"God is the first mover, Himself unmoved."
Thomas Aquinas
Imagine you’re sitting in a park, watching someone roll a ball down a hill. You know that the ball didn’t start rolling by itself—someone had to give it a push. That’s a simple way to understand what Thomas Aquinas was talking about when he explained his idea of motion. He wasn’t just talking about things physically moving, though; he was talking about any kind of change, like how a fire makes a piece of wood hot or how a seed grows into a tree. In every case, something causes the change.
Aquinas believed that nothing could change or move by itself. For example, a stone won’t just decide to roll on its own, and a fire won’t just appear out of nowhere to heat a piece of wood. Everything in the world needs something else to get it going. But here’s the big question: if everything is moved or changed by something else, what started it all? If you keep tracing back through all the causes—like following a chain of dominoes—you eventually have to reach the beginning. If there wasn’t a first cause, then nothing would have started moving or changing in the first place.
This is where Aquinas said there must be something, or someone, who started everything but wasn’t started by anything else. He called this the “first mover,” and he believed this is God. God, he said, doesn’t need anyone or anything to make Him exist. He’s eternal, unchanging, and the reason why anything else exists at all. Without this first mover, the whole chain of causes and effects we see around us wouldn’t make sense.
Think of it like a line of falling dominoes. The last domino only falls because the one before it tipped over. And that one only tipped over because the one before it did. But if there was no one to push the very first domino, none of them would fall. For Aquinas, God is like that person who gives the first push—He gets everything started.
Now, some people don’t agree with this idea. They might say, “What if the chain of causes and effects has always existed? What if there’s no need for a first mover at all?” Others think that science, like the Big Bang theory, might explain how everything started without needing God. But Aquinas believed that no matter what science discovers, there still has to be something that explains why anything exists at all. For him, that something was God.
I think this is such an interesting idea to think about, especially when you look at the world and wonder why it’s here. For Aquinas, it all came back to God being the source of everything. He’s the one who set it all in motion, the one who keeps it all going, and the one who gives it meaning. It’s like looking at a beautiful painting—once you realize someone painted it, you can start to appreciate not just the painting but also the artist who made it. That’s what Aquinas wanted people to understand: the world is like a masterpiece, and God is the artist behind it all.
So, the next time you see something moving, growing, or changing, think about how it all started. It might just lead you to some big questions about life, the universe, and who made it all happen. And those are some of the best questions to ask.