St. Thomas Aquinas’ 5 Arguments for the Existence of God

Long before Jesus, Christianity, and the likes of St. Thomas Aquinas, the Greek philosopher Aristotle came tragically close to determining the existence of God through his own conjectures and determinations. But, as he did not have the benefit of divine revelation, his findings were incomplete.

Fast-forward 1500 years and we see St. Thomas Aquinas produce a set of similar arguments that, with the benefit of Christianity, shows us a much fuller picture of why God must exist. Patrick spent a segment of The Patrick Madrid Show discussing and expanding upon these arguments for the edification of his listeners.

  1. Motion – Locomotion is the concept of an object moving through space. We live in a world of locomotion. Even when we lie asleep, our body is in motion: our cells, atoms, molecules, and cells are constantly moving to keep us alive. When we die, we cease to be in motion. Motionlessness is a symptom of being either unanimated or inanimate. But, as animate beings, we know that there must be an “animating principle”.

Essentially, just as there is something that makes dead or inanimate things not move, there must be something that makes alive or animate things move. What causes a body’s cardiovascular, respiratory, and neurological systems to function? That life-giving principle is the soul, whether others choose to call it that or not. As Christians, we know it as the soul.

And ultimately, tracing all the dominoes back through human and universal history, someone had to be the first mover to set it all in motion. Billiards balls on a table don’t move unless a player hits them with the cue. A caboose doesn’t move along a track without being pulled by the cars and engine in front of it. Human beings aren’t set in motion with our souls without a creator.

  1. Efficient Causality – This is a fancy way of saying that nothing comes into existence on its own. Everybody and everything is here because of the actions of someone or something else. Plants grow when seeds are placed in fertile soil, and they are exposed to a sufficient amount of rain and sunlight. Structures are built when beings take objects around them and arrange them in such a desired fashion.

Our existence is a result of the physical union of our parents; their existence, a result of their parents. And so on and so on all the way back to what must have been the first human beings. Our heritage cannot, by the definition of efficient causality, go on forever. There had to be a “first cause”, the one who made something out of nothing at the beginning of time.

  1. Possibility & Necessity – Everything in the universe is either necessary or contingent (unnecessary for the existence of any and everything). Nothing that is contingent is able to have existed for all time because at one point in time, that thing did not exist. And vice versa: by not having existed for all time, it is contingent. And, by the second proof, we’ve learned that things can only exist by the means of something already existing.

So, if everything is contingent (not having existed forever), then there should be nothing now. The universe should not exist. But, as we can see, there are things. There are galaxies, stars, planets, plants, animals, people, and many other wonderful and frightening things. So, that means there must be at least one necessary thing to have made all of us contingent things exist. That necessary being is God.

  1. Gradation – The argument of gradation is based on the idea of the differing degrees of perfection. While the ideas of beauty and perfection are often thought of in subjective terms, the concept of perfection in a vacuum insists that there is a point of finality when approaching a degree of goodness.

Some things tend toward perfection and others away from it. A straight line can be recognized as straight because you can compare it to your idea of a perfectly straight line. A crooked line can be seen as imperfect or failing to match the standard by the same method of comparison.

That method, however, is impossible without an ultimate standard of good. How do we know to compare things to others in that way without a mental capacity for understanding that there is ultimate perfection against which all other things are measured?

  1. Intelligent Design – Why do certain chemicals bind in a certain way? How do fractals exist in a natural form? Who implemented the laws of gravity and motion? Who implemented any of the laws of nature for that matter? Why is there some degree of order in the world? Why are human beings and other animals perfectly suited to be this planet’s inhabitants?

Analyzing nature and creation, we can see that there are a set of constant and immutable rules to which the world and the universe around it complies. In other words, we can observe the world function according to a grand design.

Tune in to The Patrick Madrid Show weekdays 8am – 11am CT

John Hanretty serves as a Digital Media Producer for Relevant Radio®. He is a graduate of the Gupta College of Business at the University of Dallas. Besides being passionate about writing, his hobbies include drawing and digital design. You can read more of his daily articles at and on the Relevant Radio® app.