Does Change Prove God Exists?

Imagine a cheeseburger appears on the table in front of you. You ask where it came from. I say, "Nowhere. It just popped into existence." You wouldn't take me seriously. Nobody would. We all operate with a basic conviction that things don't just appear out of nothing. Something has to account for them.

Now take that intuition and push it somewhere unexpected. If things can't come from nothing, then how is any change possible at all? And if change requires explanation, what kind of explanation could possibly be ultimate enough to ground all the change we see around us?

That's the argument from change, and it's one of the oldest and most powerful arguments for the existence of God. It traces back to Aristotle, was refined by Thomas Aquinas, and has been developed in the contemporary literature by philosophers like Edward Feser. To understand it, we need to start with a puzzle that's older still.

Parmenides and the Impossibility of Change

Parmenides of Elea, a Greek philosopher of the 5th century BC, held a view that sounds absurd on first hearing: change is impossible. Not that things stay fundamentally the same despite surface-level variation, but that any change whatsoever is a logical impossibility.

His reasoning is surprisingly hard to dismiss. Start with the principle that something can't come from nothing. That seems obvious enough. Now consider a real case of change. I'm a brown-skinned man. There is no red in my skin right now. Red does not currently exist on me. And yet, if I spend too long in the sun, I can become red. I get sunburnt. Red, which did not exist, now exists. Where did it come from?

Forget the biological mechanisms for a moment. The question isn't about melanin and UV radiation. The question is metaphysical: how can something that didn't exist come to exist? That seems to be exactly the kind of "something from nothing" we just said was impossible.

Parmenides formalizes this: something can't come from nothing; change is the bringing about of something from nothing; therefore, change is impossible.

The obvious objection is empirical. We see change everywhere. Samuel Johnson famously responded to a similar philosophical claim by kicking a stone and declaring, "I refute it thus." But Parmenides has a reply: your senses and your reason are in conflict, and your senses can deceive you. When you dream, your senses deliver a fully convincing experience of a world that doesn't exist. So when reason proves that change is impossible and your senses say otherwise, you should side with reason.

There's also a self-refuting quality to the argument. If Parmenides asks you to change your mind about whether change is real, he's presupposing that change is possible. You read his argument. That's a change in you. He's asking your mental state to go from "change is possible" to "change is impossible," which is itself a change. The argument seems to undermine itself.

But the deepest response comes from Aristotle, and it's this response that opens the door to the argument for God.

Aristotle's Solution: Act and Potency

Aristotle noticed that Parmenides' argument depends on a particular picture of what change involves. On that picture, brown exists, then brown ceases to exist and is replaced by red. But if that were right, we wouldn't really have change at all. We'd have one thing being annihilated and another thing being created. Brown doesn't change into red. Brown is eliminated, and red appears.

Aristotle says that's not what happens. Change involves a substratum, something that persists through the change. In the sunburn case, my skin is that substratum. Brown doesn't change into red. My skin changes from brown to red. The skin endures; its color changes.

More importantly, the substratum must have the potential for the change. My skin can turn red because it has the capacity to do so. Could my skin turn white? No, because it doesn't have that potential. The redness, in a sense, already exists in me as a potency, a real but unrealized capacity. So change isn't the creation of something from nothing. Change is the actualization of a potential. The red was always possible. The sun made it actual.

This distinction between actuality and potentiality is the key to everything that follows.

The Argument from Change

If change is the actualization of a potential, an immediate question arises: what does the actualizing?

Consider a dung beetle named Sisyphus. He needs to roll his ball from the beach to his home at the mountain summit. The ball has the potential to be at the summit, but that potential doesn't actualize itself. Something merely potential, by definition, isn't actual. It can't do anything, because doing things requires actuality. The beetle has to push it. Something actual has to make the potential actual.

But then the beetle himself was once merely potentially pushing the ball. Something had to actualize him, too. And whatever actualized the beetle needed actualizing. You get a chain of actualizers, each one requiring something prior to bring it from potency to act.

Can this chain extend infinitely? Think of the old story John Locke relates about a Hindu philosopher who was asked what holds the Earth up. An elephant, he said. And what holds up the elephant? A turtle. And the turtle? "It's turtles all the way down."

The problem with turtles all the way down is that a turtle standing on nothing doesn't add support to anything above it. The support has to come from the ground at some point. Only then can anything be held up. Adding more turtles to infinity doesn't help if there's no foundation. You'd just have an infinite number of falling turtles.

The same logic applies to actualization. If every actualizer in the chain is itself merely potential until something else actualizes it, then an infinite chain of such actualizers never introduces any actuality into the system. You'd have an infinite number of potentialities, and nothing would ever become actual. But things do become actual. Change is real. So there must be something at the foundation of the chain that doesn't itself need to be actualized, something that is purely actual, with no unactualized potential.

This is worth pausing on, because it distinguishes the argument from change from the more familiar Kalam cosmological argument. The Kalam argues that there can't be an infinite regress of causes stretching back in time. The argument from change is different. Even if you grant an infinite series of causes, the argument still works. Imagine an infinite line of billiard balls, each causing the next to move. Even if this chain has no beginning, every ball in the chain must be actual in order to cause anything. And to be actual, each one requires something to actualize its potential to exist. The argument isn't about the impossibility of infinite series. It's about the fact that potentiality can never be the ultimate explanation for actuality, no matter how many links you add.

So something purely actual must exist: something with no potential that needs actualizing, no capacity that hasn't been realized, no gap between what it could be and what it is. Since potentiality is what limits actuality (if you have the potential to be something, you lack that actuality), a being of pure actuality would be a being of unlimited, infinite actuality. And this, the argument concludes, is what we call God.

The Objection from Imagination

The argument depends on the law of causality: no potential can be actualized unless something already actual actualizes it. Normally, nobody questions this. But because it appears in arguments for God's existence, some philosophers have tried to undermine it.

The most famous attempt comes from David Hume. Hume argues that whatever is imaginable is possible. Unicorns don't exist, but we can imagine how they would be possible, and that's enough to establish their possibility. Now, Hume says, picture an empty space. Then picture a pterodactyl popping into existence in that empty space. You've just imagined something beginning to exist without also imagining its cause. So an object can begin to exist without a cause.

There are several problems with this. First, conceiving of something beginning to exist without simultaneously conceiving of its cause is not the same as conceiving of something beginning to exist without a cause. I can imagine a house without imagining the builders, but that doesn't mean I've imagined a house that was never built. I've simply left the builders out of my mental picture.

Second, the philosopher G.E.M. Anscombe raises a sharper challenge: how do you know you're actually picturing a pterodactyl coming into existence from nothing? Maybe what you're really picturing is a pterodactyl that was somewhere else and teleported to this location, like an alpha particle. Or maybe you're picturing particles that oozed through space like gas and assembled at this spot. You might be seeing the second half of a causal process and mistaking it for uncaused origination. You can't tell, from the mental image alone, that there's no cause.

Third, the law of causality is overwhelmingly supported empirically. We always find that things which come to be are caused by something. In cases where the cause is mysterious, we don't conclude there was no cause. If someone dies of a bullet wound and we can't find the shooter, we don't decide the bullet appeared in the victim without a cause. We conclude we just don't know who did it. If uncaused events were genuinely possible, we should expect to see things popping into existence all the time. But we never do.

The Objection from Quantum Mechanics

A more scientifically sophisticated objection appeals to quantum mechanics. Some philosophers and scientists claim that quantum field theories show particles can come into existence and go out of existence at random from the quantum vacuum. Two features of this are supposed to threaten causality: the particles seem to come from "nothing," and they seem to appear randomly, without any determinate cause.

On the first point, the quantum vacuum is not nothing. It is a sea of fluctuating energy governed by physical laws. Virtual particles arise from energy fluctuations in this field. Calling it a "vacuum" is misleading if it suggests an absence of anything whatsoever. Furthermore, even the physical laws themselves aren't nothing. Consider an invented creature called a "shmomerath." Shmomeraths have never existed, will never exist, and no one has ever conceived of them. There are no Platonic forms or ideas in anyone's mind corresponding to them. Could it be true that shmomeraths are venomous? It seems deeply odd to say that a claim could be true with nothing in reality corresponding to it at all. If that's right, then physical laws require something real to ground them. Even if you could somehow eliminate the quantum vacuum, you wouldn't eliminate all causes, because the laws governing the process would still need a ground.

There's a further point that often gets overlooked. Mathematical equations can't capture causation. Consider F=ma. If force increases and mass stays constant, acceleration increases. But does the equation say that force causes acceleration? There's no room in the equation for causation as such. It describes a correlation, not a causal mechanism. In quantum mechanics, all we have are mathematical formalisms. So even if a cause exists, the equations aren't the kind of thing that could reveal it. The absence of causation from the mathematics doesn't entail the absence of causation from reality.

On the second point, the claim that particles appear randomly is supposed to mean they appear indeterminately, without any cause determining that they will appear. But as the philosopher E.J. Lowe has argued, a cause can produce its effect indeterminately. A cause doesn't have to determine its effect with certainty in order to be a genuine cause. Indeterminacy in the effect is compatible with causation.

Alternatively, there may be hidden variables. Perhaps quantum indeterminacy only appears indeterminate because we lack access to the underlying deterministic structure. The philosopher Alexander Pruss has constructed a scenario to show this is at least logically possible. Imagine that at each point in space there exists a real entity (call it a monad), a dimensionless point totally disconnected from all other points, containing a complete record of every particle that will come to be or cease to be at that location. The monad causes the particles to appear and disappear according to this record. The scenario is not plausible, but it doesn't need to be. It only needs to be logically possible in order to show that hidden variables can't be ruled out. And if hidden variables are possible, then quantum mechanics hasn't demonstrated genuine uncaused events.

What the Argument Establishes

The argument from change doesn't rest on any particular scientific theory, and it can't be refuted by one. It starts from the most basic feature of our experience, that things change, and follows the logic wherever it leads. If change is real, and change is the actualization of a potential, and no potential can actualize itself, and an infinite chain of merely potential actualizers never introduces actuality, then something purely actual must exist. The objections from imagination and quantum mechanics, while worth taking seriously, don't ultimately succeed in undermining the causal principle on which the argument depends.

Whether you find the conclusion compelling or not, the argument deserves a careful hearing. It asks a question that most people never think to ask, not what caused this or that particular change, but what makes change as such possible. And its answer, a being of pure, unlimited actuality, is at minimum one of the most fascinating proposals in the history of philosophy.