The Terminus of Causality

why the universe requires a first cause, why that first cause is the Christian God, and why it matters

In the pursuit of philosophical truth, perhaps the most fundamental question we can ever ask is: why does anything exist at all?

This question isn’t just for philosophers and theologians sitting in ivory towers. This is a question billions of intelligent people have wondered. It’s a question that shapes everything we think and do. And it’s a question that you, Reader, should also be asking.

Whether you’re sitting under a starry night sky and marveling at the glory of it all, contemplating the miracle of birth, or reading a physics textbook, we all—at one level or another—wonder about the origin of everything. Those who do not have lost the child’s urge for curiosity. They no longer ask the deepest, biggest questions. This is a fatal problem because we aren’t mindless, brainless automatons. We are intelligent creatures with intelligent motives and intelligent actions. The second we cease being curious and questioning our deepest assumptions, we lose our independence.

It is the glory of God to conceal a matter, but the glory of kings is to search out a matter.

- Proverbs 25:2 (NASB95)

So……why does anything exist?

Among the many approaches to this question (some good, most terrible), one line of reasoning stands as both ancient, enduring, and incredibly powerful: the concept of a First Cause—what Aristotle called the Unmoved Mover. This post explores that concept in detail, formally known as the Terminus of Causality, or the point at which all chains of explanation must finally come to rest.

Casual Chains & Contingency

Let’s begin with a simple observation: things that begin to exist have causes. Trees grow from seeds. Houses are built by builders. Babies are born from parents. Storms arise from the convergence of air fronts. Each of these relationships forms what philosophers call a causal chain—a series of events (or entities) where each step depends upon a previous step.

Adopting this mental framework isn’t exactly optional. It’s how everyone, including you, interprets reality…..whether you realize it or not. Let me show you how:

Humans everywhere, at every stage of life, in every situation, have always asked why? Parents worldwide will smile when I ask them how many times they have told their child to do something—and instead of doing it, the child responds by asking why? You’ve probably seen that exact scenario play out a thousand times. Neither you nor your 5-year-old realizes that in doing so, they perfectly display one of their deepest assumptions: that there is, after all, an answer to the “why”. There is a reason why you told them not to run across a five-lane freeway. Perhaps they can’t see it, but they do see that there must be some reason behind the command.

However, this framework goes much deeper than a simple reason for not running across a freeway. How do you think we got science? We have science because men began asking what caused the little things: the apple falling from the tree, the heart continuing to beat, or birds soaring through the sky. Science is an enterprise of discovering causes in biology, chemistry, physics, astronomy, and beyond. We assume all things (events or entities) are caused because they are logically contingent: they could have been otherwise, or not have existed at all. Yet they are here. So how did they get here? What caused them?

Let me use the example of the apple falling from the tree. We see the apple fall from the tree and know the primary cause is gravity. But then we ask: what causes gravity? Well, we know the Earth’s mass causes gravity. Then we ask: what causes Earth’s mass? In other words, why is Earth’s mass exactly what it is? And how did it get there? Perhaps one might say the Big Bang caused it. Then we would ask, what caused the Big Bang? Some might say God, or others might say it caused itself (a contradiction in terms). This just keeps going further and further back.

Everything in the known universe functions this way. Therefore, from the most enormous black hole to the tiniest quark on Earth, the universe relies upon this transcendent law of contingency.

Incidentally, this proves a second point crucial to understanding the future arguments in this post: Since the universe is contingent upon something outside of itself—in other words, the cause for its existence is not necessary or held within itself—it must have had a beginning. There’s no way around this conclusion. Everything contingent exists solely because something else made it so. It possesses no self-sufficiency in itself.
This can also be demonstrated through the Principle of Sufficient Reason (PSR). The PSR states the following:

Everything that exists has an explanation of its existence, either in the necessity of its own nature or in an external cause.

The Principle of Sufficient Reason

Since the universe does not possess an explanation of its existence within itself, it is necessary to conclude that the explanation of its existence is held in an external cause. This makes it impossible for the universe to be eternal, since being eternal would require non-contingency.

From this, it’s reasonable to infer that the universe began.

But back to the original issue of casual chains: you can see that the further we go, the more apparent the problem becomes. How long will it be before we hit something that was never caused, and yet caused everything else? Will we ever actually hit that Something? Thus, the crucial dilemma arises: can these causal chains continue forever?

The Problem of Infinite Regress

Imagine a row of dominoes, each falling because the one before it toppled. The falling of one domino is explained by the motion and subsequent impact of the previous domino. But what would happen if the chain stretched backward infinitely? Could the entire sequence of toppling dominoes be explained away by an infinite regress of causes?

The answer, not surprisingly, is no—for two reasons:

First, there is an actual physical contradiction within the above scenario. If the chain of dominoes has been falling one after another for eternity past, it never would have reached the present point. To get to any point, you must begin somewhere. If you never start, it’s physically impossible (in our understanding of time) for any specific point to be reached.

Second, we already accepted that everything must have a cause. An infinite series of contingent causes still requires an explanation for the cause of the series itself. Each domino is dependent on another domino; none of them possess the power within themselves to begin the chain reaction. None of the dominoes possess the power of existence within themselves, since they are the objects being affected—in other words, they are in motion. Whoever or whatever caused the dominoes to begin their infinite toppling must either be entirely outside of the motion, or be inside it but unaffected by the motion in any way, shape, or form. Obviously, none of the dominoes fit either of those profiles.

To explain the existence of the causal series, we must reach something or someone that is not part of the chain. We must reach something that does not require a cause. Something that exists necessarily, not contingently. If it existed contingently upon something else, we wouldn’t have reached the First Cause—we would have just reached another step in the chain. Whatever this thing would be, it must possess within itself the cause or reason for its own being.

This is the terminus of causality—the point at which explanation itself rests. Not because we’ve given up, but because we’ve finally found solid ground.

The Nature of a First Cause

What must this Terminus of Causality, this First Cause, look like?

• It must be uncaused: if it had a cause, it would not be the First Cause. It would simply be a part of the chain of causal contingency we’re trying to explain.

• It must be independent: it cannot depend upon anything outside itself.

• It must be necessary: it cannot fail to exist. If it failed to exist, reality would collapse solely because this First Cause is the source of everything.

• It must be eternal: since time as we know it is a causal chain, this First Cause must be outside time and initiate it.

• It must be immaterial: all matter is part of the contingent universe, and therefore, since this First Cause isn’t contingent upon anything, it must be outside of matter.

• It must be immensely powerful: it must have the capability to bring everything in reality into being.

• It must be personal: perhaps the most surprising thing is that this First Cause must be intelligent and capable of willing. More on this in a moment.

The Personal Agent Problem

We need to stop here to establish a fundamental point. Many will say that this First Cause, while necessary, doesn’t need to be a personal, intelligent entity. Instead, it could be a timeless, impersonal force: a metaphysical law or a principle of logic, perhaps.

Unfortunately, that’s impossible. Only a personal agent can initiate a finite effect from an infinite cause.

Let me explain. If the First Cause were a mindless law or impersonal force, its result—the universe—would be produced as soon as the conditions were right. When would the conditions be right? They would be right the instant the First Cause came into being. However, we know that the First Cause is eternal. Thus, an impersonal First Cause would necessitate that both the cause and the effect (the universe) are infinite.

But the universe is not eternal. It began.

So we are forced to ask: what caused the First Cause to cause that effect at that particular moment?

There is only one obvious conclusion, which we have no option but to resort to. The First Cause must be a personal, intelligent entity capable of willing actions. You see, impersonal causes cannot make choices. They cannot delay, and they cannot create new conditions or set new parameters. They function like a machine: unconscious and automatic. They act when they must. So if the cause were impersonal, the universe would have always existed. But we know that it didn’t always exist.

If, instead, the First Cause is a personal being—a mind with will—it could freely initiate a new effect, such as the universe, at a specific moment. This aligns perfectly with what we observe: a universe that began to exist a finite time ago, despite being caused by an eternal source. And by the way, this isn’t just philosophy. Science supports these conclusions. The supermajority of professional scientists agree that the universe began. They have different reasons why: Creation, the Big Bang, a multiverse generator. etc., but for the most part, they all agree. And those who challenge this conclusion are faced with several serious issues. For example, we know that the universe is constantly expanding and, to the best of our knowledge, has been expanding for its entire existence. If you had a time machine and were able to speed back into history, you would see the universe shrinking smaller and smaller until eventually……it would cease to exist. The universe expanding now necessitates that it began at some point.

From First Cause to Yahweh

Having followed the logic of causality to the very end, we find ourselves face-to-face with the First Cause—an uncaused, independent, necessary, eternal, immaterial, immensely powerful, and personal force. We have a word for an entity that possesses these attributes: a being.

So who is this being? Some suggest the First Cause is an abstract force, an alien intelligence, a multiverse generator, or something completely unknown and foreign to us. But such suggestions collapse under scrutiny. When we ask what kind of being could ground all of reality?, we find that only the Christian God as described in Scripture fits the profile.

Let’s examine why.

1. The First Cause must be immaterial, immortal, and unchanging. In order for it to begin time and cause all matter to exist, it must be outside of both time and matter itself. A physical or natural force can’t be the First Cause because all physical and natural forces are bound by laws and conditions. The First Cause also needs to be unchanging—what philosophers call a pure actuality. This essentially means it cannot be changed or caused in the way the universe can. It has to be a solid, rock-hard, unmovable foundation holding all of reality.

   The Bible describes Yahweh as all of those things. He is eternal (Psalm 90:2; 1 Timothy 1:17), unchanging (Malachi 3:6), and beyond creation (Genesis 1:1, John 1:1-3). None of this is coincidental. This is the Bible showing us the philosophical necessity of God’s existence.

2. The First Cause must be personal. Like I mentioned above, some will describe the First Cause as an impersonal force or principle upon which the universe rests. However, we know this is impossible. Impersonal entities don’t have the ability to choose anything: they just act automatically when the conditions are right. If the First Cause was indeed an impersonal force, the effect (the universe) would also have to have existed eternally. But we know that the universe is not eternal. It began. So the First Cause must be able to choose, to freely cause the universe at a particular moment. This implies personhood—will, intention, agency.

   Again, we see this all over the Bible. God is personal (Genesis 1:1; Genesis 18:20-21; Exodus 33:11; John 3:16). The Book yet once again anticipates our philosophical objections and answers them perfectly to demonstrate that God is the First Cause.

3. The First Cause must be all-powerful. To create time, space, matter, & energy, to bring reality into existence, and to fine tune the laws & constants of the universe—all from ex nihilo (out of nothing)—requires power far beyond comprehension. The cause must not be powerful in a limited or finite sense, but absolutely and completely sovereign over all possible realities.

   The God of the Bible is omnipotent (Jeremiah 32:17; Genesis 1:1; Isaiah 40:26; Colossians 1:17; Romans 8:28). There is nothing He cannot do. This isn’t just religious exaggeration and poetry: it’s exactly what the First Cause demands.

4. The First Cause must be necessary and self-existent. The universe is not necessary. It’s contingent—it could have not existed. But the First Cause must exist by its very nature, or else it wouldn’t exist at all. It cannot derive existence from something else, because it isn’t contingent upon any other entity. It is necessary.
   
   This attribute eliminates all finite or created gods from other religions. Pagan deities are contingent—they are born, die, or emerge from chaos. Did you know that only the biblical God claims self-existence? “I AM WHO I AM” (Exodus 3:14). This is literally the first books of the Bible, written millennia before ancient philosophers developed these intricate theories, giving us a perfect case for God being the First Cause—or, as Aristotle called it: the Unmoved Mover. Only the God of Scripture claims the kind of necessary, uncaused, eternal being that logic demands.
   
   “For as the Father has life in himself, so he has granted the Son also to have life in himself.” (John 5:26)

5. The First Cause must be intelligent. The universe is finely tuned, governed by invisible, immaterial rules, structured according to the laws of math, and obviously ordered with life in mind. To give you an idea of how impossible it is that this happened by chance, let’s take a look at the odds of just one of these things: fine tuning. Fine tuning is “the observation that the fundamental physical constants and laws of nature appear to be precisely set within narrow ranges, allowing for the existence of life as we know it.”
   
   Mathematicians have worked out that the odds of the universe randomly exploding into being and landing on all the right parameters for fine tuning are more than 1 in 10000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000.
   
   That’s right.
   
   What you’re looking at is a 10 with 120 zeroes after it.
   
   And remember…..that’s the conservative estimate! Some scientists think that the odds are much greater, around 1 in 10 with one thousand zeroes after it. This is what that would look like:
   
   100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000.
   
   To put this into perspective, the exact number of molecules in the entire universe is around 10 with eighty zeroes after it:
   
   1000000000000000000000000000000000000000000000000000000000000000000000000000000000.

   
   As you can see, is quite literally a mathematical impossibility that something intelligent didn’t exactly tune the laws and constants of physics specifically for life. Thus, we see that the First Cause must be not only powerful and personal, but intelligent—a mind capable of designing reality. Once again, the Bible comes through for us. God is wise, all-knowing, and omniscient (Proverbs 3:19-20; Psalm 147:5; Hebrews 4:13; Job 37:16; 1 John 3:20).

6. Finally, let’s examine some common alternate explanations for the First Cause:

   • A multiverse generator: It’s still contingent. Any “multiverse generator” would itself require explanation and cannot be self-existent if it is composed of parts or change. And who would have started the generator running in the first place? Since it has generated a given amount of multiverses, it must have begun at some point.

   • Quantum fields: Still material and governed by laws. Fields fluctuate, and fluctuations are events—contingent ones. Keep in mind that the First Cause must be unchangeable and impossible to manipulate. Also, this explanation doesn’t make any sense whatsoever to begin with.

   • An alien intelligence: While this is probably the most logical alternative explanation, it’s still contingent. Anything embodied, limited, or emergent (i.e., aliens) is not necessarily existent within itself.

   • An unknown force: This one is so ridiculous it deserves nothing more than to be laughed at. The Bible has presented a candidate for the First Cause. This candidate (God) fulfills every requirement and demonstrates perfectly that nothing but God can be the First Cause. If you ignore this and pretend like it’s still impossible to know what the First Cause is, you’re just dishonest. There’s no other answer.

In conclusion, we have followed the line of causality as far as reason and common sense will permit us. We have shown that everything which begins to exist must have a cause, that the universe itself began to exist, and that anything contingent—anything which depends on something else—cannot exist infinitely into the past or into the future without an ultimate source. That source must be necessary, uncaused, eternal, immaterial, personal, and powerful beyond comprehension.

Science cannot give us an answer to this. According to the scientific community, time, matter, and energy themselves came into being at the Big Bang—an event with no natural cause. Philosophy cannot bypass it. An infinite regress of causes is not just implausible; it is logically incoherent. It has to stop someplace. There must be a First Cause: someone or something that exists solely by the necessity of itself. Something or someone that does not receive existence from any external source—but rather from an internal source. It also must be personal, making it impossible that this entity is anything but an intelligent deity.

However, this is not just a deity. It must be a Mind. A willful Creator. A source of reason, beauty, power, and moral authority.

It must be Yahweh.

It must be the God of classical theism. The God who revealed Himself to Moses as “I AM,” who exists necessarily, whose being depends on nothing else, whose creative power spoke the cosmos into being, created man from dust and woman from man, breathes life into every newborn, and sets His moral law within us.

This is no arbitrary leap or “God of the gaps” hypothesis. The attributes required of a First Cause—eternality, necessity, omnipotence, immateriality, timelessness, and personal agency—match precisely the God described in Scripture.

There is only one terminus of causality that fits both the philosophical requirements and the existential hunger of mankind. There is only one foundation solid enough to ground all being, all beauty, and all truth.

And this, all men call…..God.

- Thomas Aquinas