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Why Science Can’t Do Away with God

Modern science assumes it can explain the material world without an appeal to a Creator, but Thomas Aquinas shows us why it can’t.

It’s a common belief that science has buried God. This belief assumes that modern science explains all the features of the material world without an appeal to God, and every new advance of natural science is seen as one more nail in the divine coffin.

But arguments for God’s existence are grounded in philosophical premises about material reality that natural science presupposes. In other words, these premises must be true in order for empirical scientific methods even to work. And since science presupposes these features, it cannot possibly explain them and thus cannot explain away the need for God.

So, what are these features?

Change, being, and non-being

One is change. If you were to conduct an experiment to find out the degree of heat needed to turn natural rubber into a lump of goo, you would subject different pieces of the same rubber to different temperatures. Now, the rubber turning into a lump of goo is an instance of change. Without the assumption that change is real, the experiment would be futile. Not only does science presuppose the reality of change, it also presupposes the fundamental features of material beings necessary for change to be possible.

Someone who didn’t presuppose that change is possible was the ancient Greek philosopher Parmenides. In his view, the only thing other than being is non-being. As it relates to the above experiment, this would mean that anything other than the state of being natural rubber—such as the state of being a lump of goo—is non-being, or nothingness.

Parmenides reasoned that, if change were to occur, what would come into being would come either from what is (being) or what is not (non-being). Since there would be no change if being came from being (a state of being a lump of goo coming from a state of being natural rubber), and since something (a lump of goo) can’t come from nothingness (no lump of goo), Parmenides concluded that change is an illusion.

Being-in-potency

In response, another Greek philosopher—Aristotle—rightly pointed out that Parmenides failed to distinguish between something coming from what-is-not in an absolute sense (non-being) and something coming from what Aristotle called “deprivation” or “being-in-potency” (Physics, 1.8). By these he meant a lack of something for which a thing has potential—a mode of being that is a middle ground between non-being and actual being.

For example: it’s accurate to say the piece of natural rubber is neither a dog nor a lump of goo. But the deprivation (“is not-ness”) in each case is different. Given the kind of thing rubber is, it cannot become a dog; but it does have potential to become a lump of goo. Therefore, the being-in-potency for a lump of goo inheres in the rubber, even though it’s not actually a lump of goo. Therefore, being-in-potency is a sort of middle ground between nothingness and actuality.

What this tells us is that things have a potency for being actualized in some way. Philosophers would say these things have an inherent directedness to a particular outcome, or range of outcomes, as an end or goal. This “built-in” potency is nothing more than Aristotle’s understanding of final causes: the “that for the sake of which” something exists (Physics, 2.3). Philosophers refer to this as immanent teleology (Greek, telos, “end” or “goal”).

Substantial forms

You still with me?

Okay, for a material being to be inherently directed to some state of actuality (or range of actual states) is for it to have what philosophers call substantial form—that intrinsic “principle of being which together with matter constitutes the essence of a body” (Henry Koren, An Introduction to the Philosophy of Nature, 45). Aristotle called it a thing’s formal cause.

Again, consider the piece of natural rubber. It has the potency to become a lump of goo (and not granite or steel) only because it’s the kind of natural substance it is. But for natural rubber to be a particular kind of thing—to have an essence or nature—is just to have a substantial form.

Substantial form goes hand in hand with immanent teleology (or final causality). To affirm the latter is to affirm the former, and to deny the latter is to deny the former.

Efficient causality

Although “being-in-potency” provided Aristotle a way to explain change without falling prey to Parmenides’s critique, the explanation of change is not complete until one includes a changer—what philosophers call an efficient cause.

Consider, for example, how the experimenter begins his experiment with the goal of melting the piece of rubber. He recognizes that the rubber has the inherent potential to become a lump of goo. But in order to actualize that potential, he must use something that can generate heat, such as fire, since the rubber cannot melt itself. If it could, it would be simultaneously a potential lump of goo and an actual lump of goo, which is a contradiction.

Therefore, whatever is changed must be changed by something outside itself. This is just another way of stating an Aristotelian maxim: whatever is moved is moved by another (Physics 7.1). And whatever causes the change or motion is its efficient cause.

The need for an efficient cause also reveals the tie between substantial form and immanent teleology. For example, the experimenter must use something that can generate heat—fire, say—to melt the piece of rubber. He can’t use a piece of ice.

What this tells us is that fire is an efficient cause of heat because it has a directedness to the effect of heat given its substantial form. We can express this as a formulation: if efficient cause A by nature brings about effect B, then B is the final cause of A (see Edward Feser, Scholastic Metaphysics: A Contemporary Introduction, 92). To affirm one is to affirm the other.

Explanations & presuppositions

Matter’s being-in-potency (material cause), matter’s being-in-potency for a particular state of actuality (teleology or final causality), substantial forms (formal causality), and efficient causes (efficient causality) are all inextricably linked in explaining the structure of material beings and the change that they undergo. And such a framework is what makes science possible.

As mentioned above, if the scientist didn’t think that change was possible in our rubber experiment of turning rubber to goo, there would be no reason to perform the experiment at all. Moreover, if natural rubber didn’t have the inherent potential to become a lump of goo; and fire, say, didn’t have the inherent tendency to produce heat that could actualize the potentials inhering in the piece of rubber; then the experimenter would have no reason to think that the same results would occur in repeated experiments and thus would have no ground for formulating a scientific law about the relationship between natural rubber and heat.

The experimenter must assume that each piece of natural rubber has the same kind of substantial form with its inherent potentials. He must also assume that fire of similar magnitude will generate its specific effect (heat) each time the experiment is conducted.

In other words, the scientist must assume that the tightly woven fabric of substantial forms, matter’s being-in-potency for a particular state of actuality, and efficient causality is real. Science has no choice but to accept this explanatory framework for material reality, because without it, there would be no classification, induction, or gathering of experiences into certain laws—that’s to say, there would be no natural science.

If these features of material reality are necessary for natural science to even be possible, it follows that natural science cannot in principle explain them. To say that natural science could explain these features would be akin to saying that reason can demonstrate the principle of non-contradiction. But reason can’t do this, because any demonstration of reason necessarily relies on the principle.

Similarly, the basic methods of science cannot possibly explain change and the fundamental features of material beings that make change possible, because such aspects of the material world are incarnate in the very methods of natural science.

Sketched pathways to God

How does the theistic philosopher ground the premises of his arguments in those features of material reality that science presupposes? Let’s look at brief sketches of some of the arguments.

Take, for example, St. Thomas Aquinas’s First Way: the argument from motion, which is an argument from change or the actualization of a potency (Summa Theologiae I:2:3). We start with the sense-experience of motion/change and then employ the Aristotelian principle that whatever is moved (changed) is moved by another. Since there cannot be an infinite regress of moved movers wherein every mover in the series is dependent upon all the other movers for its moving power, we conclude that there must be a first mover that is not moved. Since motion (that is, change) is the actualization of a potency, and the first mover is unmoved, then the first mover is pure act and void of all potency. Such an unmoved mover is what we call God.

Efficient causality is another feature that serves as a starting point for theistic arguments. The most common example is Aquinas’ Second Way (ST I:2:3). He starts with the common-sense observation that in the world there is an order of efficient causes (e.g., fire melts natural rubber and causes a lump of goo). And since there can’t be an infinite regress of caused causes where every cause is at every moment dependent upon other causes for its causal power, Aquinas concludes that there must exist a first cause that is not caused, or an uncaused cause. He calls such a reality ipsum esse subsistens (ST I:4:2): subsistent being itself. This is what he calls God.

Aquinas’s Third Way (ST I:2:3) uses the corruptibility and generation of material beings as its starting point, which is intrinsically bound up with the form-matter composition. For something to corrupt is for matter to lose its substantial form. And generation is nothing more than matter taking on a new form. For example, when the scientist melts the rubber and it becomes a lump of goo, the matter loses the substantial form of rubber-ness and takes on the new form of lump-of-gooey-ness.

For Aquinas, all of reality cannot consist of corruptible beings; otherwise, all things would have gone out of existence at some point in the infinite past, which is absurd. Therefore, Aquinas concludes, some being must exist that has no tendency to corrupt or to go out of existence. But something that doesn’t have the tendency to corrupt is something that is not a composite of form and matter. This is what Aquinas calls a necessary being.

Aquinas then reasons that if such a being has its necessity derivatively (and not absolutely), there would be a series of necessary beings with derived necessity. And since such an ordered series cannot regress infinitely (like the series in the First and Second Ways), Aquinas concludes that there must exist an absolutely necessary being. Such a being is what he calls God.

Theistic arguments can also proceed from the feature of immanent teleology, or final causality. Aquinas’ Fifth Way is one example (ST I:2:3). He starts with the datum that things without intelligence, such as natural bodies, always, or for the most part, act for an end.

What Aquinas puts forth here is the principle of finality described above: whatever has a potency has a potency for a particular state of actuality or range of actual states. Recall that the fire has an inherent tendency to generate heat and not the smell of lilacs.

For Aquinas, the only way a natural body can point to—or be directed to—such an end is if an intelligence directs it, like an archer directs an arrow to its target. The reason for this is that if an end or goal is to be a cause in the sense of a final cause, then it must exist. How could the oak tree that the acorn will become cause the acorn to grow if the oak tree was sheer nothingness? Nothing can cause only nothing. So, if the final cause is to be a cause at all, it must exist.

But if the end or goal doesn’t exist in reality, then the only other place for it to exist is in a mind. This is why Aquinas says, “Whatever lacks intelligence cannot move toward an end unless it be directed by some being endowed with knowledge and intelligence” (ST I:2:3). When this principle is applied to all natural things, Aquinas concludes that there must exist a supreme intelligence by which all natural things are directed to their ends. Such a being is what he calls God.

Acknowledge your limits

It’s common sense that the practitioner of a particular discipline of thought should know the boundaries and limitations of his method. Such knowledge is necessary lest he undermine his credibility by pontificating on matters to which his discipline isn’t privy. A mechanic who is only a car mechanic has no place commenting on quantum mechanics. Similarly, a scientist—as a scientist—has no place pontificating on matters that pertain to the philosophy of nature and consequently the philosophy of God.

But this is precisely what an atheistic scientist does when he says that natural science can explain everything about the material world without an appeal to God. To criticize him for making such a claim is not philosophical snobbishness. It’s merely a recognition that the features of material reality that the philosophy of nature uncovers are more fundamental than what modern empirical science can tell us about. And since natural science grounds its premises in these features, it cannot pontificate on the claims of natural theology.

The claim that modern science has buried God is made in the name of intellectual credibility. But how can one claim intellectual credibility when one fails to understand the limitations and presuppositions of one’s discipline?

Not only has science not buried God; on its own, it can’t even find a shovel.

Sidebar:

Another Type of Theistic Argument

The form-matter composition of material substances serves as a starting point for another type of theistic argument that is a bit different from Aquinas’s Third Way. The claim is that whatever is composed of form and matter cannot continue in existence for an instant without the sustaining power of a divine cause. That’s to say, no material substance has “existential inertia.”

The rationale behind this claim is that neither of the inherent principles that make up a material substance—form and matter—can account for its continued existence. Matter has no tendency to stay in existence on its own, since without substantial form it is pure potency and merely an abstraction (philosophers call abstracted matter without form prime matter).

Likewise, substantial form has no tendency in itself to stay in existence, because apart from matter it too is merely an abstraction until it informs matter to make a concrete thing. And since a thing cannot give what it doesn’t have, it follows that neither matter (as the material cause of a substance) nor the substantial form (as the formal cause of a substance) can impart a tendency to remain in existence to the material substance that they compose. And since there are no other principles inherent within a material substance, it follows that no material substance can remain in existence on its own.

What this implies is that at every moment a composite substance of form and matter exists, it requires a cause outside itself to sustain it in existence—what philosophers call an existential cause. And since there cannot be an infinite regress of existential caused causes ordered in such a way that every cause in the series relies on other causes for its existential causal power, there must exist an existential cause that is not caused (an uncaused existential cause). Such a reality is what some such as Aquinas would call God.

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