I have been doing a read through St. Thomas Aquinas’ Summa Theologica recently, along with Brian Davies’ newly published commentary on the text–Thomas Aquinas’s Summa Theologiae: A Guide and Commentary (2014). I’ve also decided to blog some of my thoughts and notes along the way, in order to discuss a few of the differences between Christian theology and metaphysical naturalism. In this post, I will be discussing some of the implications of Aquinas’ theology for the possibility of there being empirical evidence of God’s existence, particularly with regards to how Aquinas describes God as the object of the study of his sacred science (part I, question 1, article 7), and Aquinas’ Five Ways of demonstrating God’s existence (part 1, question 2, article 3).
I am frequently asked by Christian theists and apologists what evidence or arguments I would find persuasive for God’s existence. One of the pet peeves that I have with many theological arguments, however, is the unfalsifiability of their core premises. Take the apologetic moral argument, for example. This argument can take a variety of forms, but consider the rather simple formulation of it advanced by theologian William Lane Craig:
1. If God does not exist, objective moral values and duties do not exist.
2. Objective moral values and duties do exist.
3. Therefore, God exists.
Now, even skipping over the meta-ethical question of how one defines “objective moral values and duties,” as well as the rather controversial fact claim being made in p2, I see little reason for an argument like this to be persuasive. The reason why is that I see no way of testing or falsifying p1. Whether objective moral values and duties can or cannot exist without God is a question of how we define and conceptualize morality. It is not a premise that can be tested against empirical data and observation.
All an apologist needs to do, therefore, to grant this argument apparent soundness, is to define moral ontology as requiring God’s existence, and then to deduce that the existence of objective moral values and duties (a premise that I am only granting for the sake of argument) thus proves God. But such arguments reduce to little more than armchair speculation. They start with arbitrary definitions of morality and then deduce conclusions, rather than inferring conclusions from demonstrable evidence. Because of this, it is very easy to use an argument like this to create specious “evidence” for God’s existence, when all one is really doing is cooking up arbitrary premises that are then inserted into a formally valid syllogism. But, even if valid, such a syllogism is not sound, if one does not accept the premises, and I see no reason to accept p1, particularly because I see no way of testing or falsifying it.
Empirical Evidence and Falsifiability
What is great about empiricism as an epistemology, however, is its ability to falsify certain kinds of predictions and claims based on demonstrable evidence. Empirical evidence is based on sensory experience and observation, and there are many kinds of religious predictions that can be tested by our senses.
Take, for example, the apocalyptic claim that Jesus would return on May 27, 2012 in order to usher in the end times of scripture. What is great about a claim like this is that it is empirically testable. All you have to do is wait until May 27, 2012, look outside, and if the world is still doing fine with no signs of apocalyptic cataclysm, then the claim has been falsified. It’s that simple.
(Note also that, if such an apocalyptic prediction proved to be true, and the world really did come to an end, this kind of empirical evidence would be far more powerful proof of God’s involvement than mere ontological arguments, which simply define God into existence with arbitrary and untestable premises.)
In fact, one of the reasons that I doubt the truth of Christianity, as a religion, is because many NT scholars agree that both the historical Jesus and the apostle Paul predicted an impending end of the world within a generation of their own lifetimes (for a basic summary of this conclusion, see John Loftus’ “At Best Jesus Was a Failed Apocalyptic Prophet”). And yet, the 1st and 2nd centuries CE have come and gone, without any sign of Jesus’ return or the apocalypse. The first generations of Christians, therefore, including Jesus and Paul, must have been mistaken.
Can God Be Empirically Observed?
When it comes to empirically testing God’s existence, however, many theologians and apologists retort that God is not an object within space-time that can be empirically observed. For example, theologian David Bentley Hart (The Experience of God: Being, Consciousness, Bliss, pg. 30) argues:
“[God] is not a ‘being,’ at least not in the way that a tree, a shoemaker, or a god is a being; he is not one more object in the inventory of things that are, or any sort of discrete object at all. Rather, all things that exist receive their being continuously from him, who is the the infinite wellspring of all that is.”
What Hart is getting at is that “God” is not just an object within the universe, but is instead the immanent source of being, upon which all contingent things are dependent. Thus, to argue that God’s existence could be falsified through empirical observation within space-time, theologians maintain, is to misunderstand the theology of God’s existence.
When it comes to Judeo-Christian religious traditions, there is some scriptural support for this idea. For example, John 1:18 states, “No one has ever seen God, but the one and only Son, who is himself God and is in closest relationship with the Father, has made him known.” And 1 Corinthians 2:9 (alluding to Isaiah 64:4) claims that the things revealed by the spirit are, “What no eye has seen, what no ear has heard, and what no human mind has conceived—the things God has prepared for those who love him.” Then again, Genesis 32:30 states that Jacob saw God “face to face,” but perhaps this is just an anthropomorphized metaphor for God. Regardless, for the purposes of this discussion, I will assume Hart’s description that God is not discrete object, which is observable within space-time, and is thus beyond direct empirical observation.
Is “Nonoverlapping Magisteria” a Good Argument?
If God cannot be empirically observed, does that mean that the existence of God is beyond the realm of empirical evidence?
On the one hand, I think there are many theists (and even certain agnostics) who would like this to be the case, because it would safely gerrymander the question of God’s existence (or religious questions more broadly) into a category that could never be empirically falsified. Take, for example, agnostic Stephen Jay Gould, who was famous for espousing the view that science and religion belong to “nonoverlapping magisteria.” In other words, Gould argued that religion deals with questions that science cannot answer, and vice versa. For example, Gould (“Nonoverlapping Magisteria”) states:
“The lack of conflict between science and religion arises from a lack of overlap between their respective domains of professional expertise—science in the empirical constitution of the universe, and religion in the search for proper ethical values and the spiritual meaning of our lives. The attainment of wisdom in a full life requires extensive attention to both domains…”
Well, how awfully convenient! If religion deals with questions like “ethical value,” which, as discussed above (as well as in my essay “Are All Norms Moral Norms?”), are normative questions that are notoriously difficult for empirical science to answer, then it looks like religion is off the hook for having to provide empirical evidence. Moreover, no amount of empirical evidence could ever falsify religion. How mightily convenient for theists, especially when they are trying wiggle out of giving demonstrable evidence for God!
For a critique of the view that science and religion simply “answer different questions,” I recommend philosopher Stephen Law’s “Has Science Buried God?.” Here is what Law argues regarding whether empirical science can validate religious claims:
“It takes only a moment’s reflection to realise that the unobservable is not off-limits to science. Science has a well-established track record of confirming and refuting beliefs about things that can’t be observed.
Take electrons, for example. We can’t observe electrons themselves. But we can observe their effects. The theory that electrons exist has observable consequences. If the theory about electrons is true, then we should expect to observe certain things – such as these bubbles in a bubble chamber – that are unlikely to be observed otherwise. If these effects are observed, then the theory is strongly confirmed. The key to understanding how claims about unobservables can be observationally confirmed or refuted is to realise that unobervables can have observable effects.”
Here, I agree strongly with Law. Even if God cannot be empirically observed directly, there can still be empirical proof of God’s existence through his effects.
Thomas Aquinas on Knowing God through God’s Effects
Here is also where Thomas Aquinas and Summa Theologica enter the equation. It turns out that Aquinas makes a very similar argument to the one that Law makes above, when describing the methods of his sacred science. In part I, question 1, article 7, Aquinas argues:
“Although we cannot know in what consists the essence of God, nevertheless in this science we make use of His effects, either of nature or of grace, in place of a definition, in regard to whatever is treated of in this science concerning God; even as in some philosophical sciences we demonstrate something about a cause from its effect, by taking the effect in place of a definition of the cause.”
In other words, even if you cannot see God, you can still see effects of which you can logically infer God is the cause. Inferring a cause through its effect is, after all, something we do regularly, as Law discusses above.
Empirical Effects of God
Perhaps the most obvious kind of effect that God could cause, which would lead to the logical inference of his existence, is a miracle. The Cambridge Introduction to the Philosophy of Religion (pg. 208) defines a “miracle” as follows:
“An event (ultimately) caused by God that cannot be accounted for by the natural powers of natural substances alone. Conceived of this way, miracles don’t violate the laws of nature but rather involve the occurrence of events which cannot be explained by the powers of nature alone. When dead bodies come back to life it is a miracle because the molecules that make up the corpse lack the powers necessary to generate life.”
Here is why miracles are a great form of evidence: they are empirically demonstrable. If the Red Sea were to suddenly part, in order to allow a group of people to pass through it, then this would be phenomenon that we could empirically observe. Turning water into wine involves demonstrable empirical change. People’s whose physical illnesses were suddenly healed, after a miracle worker placed his or her hands upon them, would provide empirical evidence for medical miracles, and so on.
I should note, too, that miracles would not be the only kind of empirical effect that God could use to provide evidence of his existence. Prophecies made under controlled conditions (in order to eliminate ex eventu prophecies), which had successful results, would also be empirical evidence of divine involvement. Likewise, successful prayer studies could provide empirical evidence of God’s existence. As Law continues to explain:
“What about the belief that there’s a God who answers our prayers? Is that scientifically testable? Yes, it is. There have been two huge multi-million dollar, double-blind scientific experiments involving prayers for heart patients, both of which found the prayers had no medical effects. One study was run by a scientist who believes in both God and the power of prayer and who was clearly disappointed by the results, so you can’t dismiss these studies on the grounds of bias.
What these large-scale studies revealed was not just an absence of evidence of the power of prayer to produce such medical results. They also revealed evidence of the absence of any such power. That’s scientific data strongly supporting the view that prayer doesn’t have that sort of medical effect.”
And so, I do not think it is true at all that there can be no empirical evidence of God’s existence. Miracles, prophecy, and answered prayers would all provide excellent empirical evidence of divine involvement. It just so happens that none of these phenomena have been verified by a successful study. Instead, we only hear of such things through hearsay, or ancient religious texts, which are notoriously unreliable forms of evidence. But that does not mean that such empirical evidence could never be provided, in principle.
However, I also want to discuss Aquinas’ Five Ways to assess the kinds of empirical evidence that he offers, and why I find his arguments to be unpersuasive.
Defining the Hypothesis of “God”
First, I will lay down a minimal attribute of God that I consider essential to any successful argument for his existence: agency. God is not an impersonal, non-mental, or non-rational concept, but instead one that implies that there is a willful intelligence behind our universe. God’s miracles, for example, are purposeful events, which are directed towards achieving certain ends. This kind of intentionality reflects the actions of an agent making conscious decisions.
For this reason, I agree with theologian Randal Rauser’s definition of the ‘minimal’ conception of God:
“Theism is minimally the position that the ultimate cause of everything that contingently exists is an agent cause. Thus, God is minimally the ultimate agent cause of everything that contingently exists. So if you believe that God exists as defined then you are a theist. If you believe no God exists as defined then you are an atheist.”
A key aspect of agency is that it involves what philosophers call teleology, or goal-orientated behavior. Not all forms of teleology, however, reflect the actions of an agent.
Platonic vs. Aristotelian Teleology
To specify the kind of teleology that I am looking for–for proof of God’s existence as an intelligent agency– I will use a helpful distinction drawn by philosopher André Ariew in “Platonic and Aristotelian Roots of Teleological Arguments.” Ariew distinguishes between two types of teleology, and their relevance to theological arguments for God’s existence: “Platonic teleology” and “Aristotelian teleology”. As Ariew (pg. 8) explains:
“Insofar as Aristotle’s teleology pertains to explanations of natural items, it is misleading to cast off Aristotle’s teleology as reading purposive behavior into natural events. This perception of Aristotle’s teleology is the result of conflating Aristotle’s naturalistic teleology with Plato’s … Plato’s natural teleology is and Aristotle’s is not creationist, anthropomorphic, and externally evaluative … Aristotle’s natural teleology is and Plato’s is not naturalistic, immanent, and functional.”
Ariew (pgs. 8-9) goes on to identify two distinct types of teleology in Aristotle’s writings:
“Teleological explanation in Aristotle pertains broadly to goal-directed actions or behavior. Aristotle invokes teleology when an event or action pertains to goals … [W]e can distinguish two distinct conceptions of teleology in Aristotle’s writings and at least two sub-categories:
I. Agency-centered teleology:
i. Behavioral. Activities undertaken for the sake of something, which may be either a state or further action.
ii. Artifactual. Activities undertaken for the sake of producing an object of a certain sort (artificial).
II. Teleology pertaining to natural organisms.
i. Formal. Biological developmental processes that occur for the sake of self-preservation or preservation of the species (form).
ii. Functional. Parts of organisms that are present for the sake of the organism possessing them.
I and II are distinct notions of teleology … Agent-specific teleology (I) is purposive, rational, and intentional, and represents external evaluation. The goal is the object of an agent’s desire or choice … Teleology pertaining to natural organisms is distinct: non-purposive (though seemingly so), non-rational, non-intentional, and immanent — that is, an inner principle of change. The goal is not an object of any agent’s desire.”
For an intelligent agent–such as God–the first type of (I) “agency-centered teleology” is the kind of evidence that I am looking for. This type of teleology is akin to William Paley’s teleological argument for God, which maintains that the universe reflects a willful process of design that points to an intelligent creator–particularly in the complexity of biological structures. However, Paley’s argument has long been refuted by the discovery of evolution by natural selection, which instead proves that complex biological structures are merely formal and functional, and are actually the result of (II) “teleology pertaining to natural organisms.” As such, complex biological structures do not point to the teleology of any rational agent.
Aquinas’ Five Ways
Now let’s take a look at Thomas Aquinas’ Five Ways, to see if any of them point towards (I) agency-centered teleology. Out of the five, Aquinas’ 5th way would seem to be the most likely candidate. In Summa Theologica, part 1, question 2, article 3, Aquinas argues:
“The fifth way is taken from the governance of the world. We see that things which lack intelligence, such as natural bodies, act for an end, and this is evident from their acting always, or nearly always, in the same way, so as to obtain the best result. Hence it is plain that not fortuitously, but designedly, do they achieve their end. Now whatever lacks intelligence cannot move towards an end, unless it be directed by some being endowed with knowledge and intelligence; as the arrow is shot to its mark by the archer. Therefore some intelligent being exists by whom all natural things are directed to their end; and this being we call God.”
Sometimes, Aquinas’ 5th way has been equated with Paley’s teleological argument for God. However, other interpreters of Aquinas do not see it that way. As Brian Davies (Thomas Aquinas’s Summa Theologiae: A Guide and Commentary, pg. 47) explains:
“Though some readers of it seem to have thought otherwise, however, the Fifth way is not an “argument from design” in Paley’s sense. It does not appeal to vast cosmic evidence of design not produced by any human being while produced by a nonhuman designer. Nor is it saying that the world is a single, huge designed object. Rather it is noting that some, and only some, things in the world “act for the sake of an end.” Aquinas is saying that, forgetting about anything we might know about human behavior, there are some things in the world that can be thought of as goal-directed in their activity, and his argument is that the goal-directed activity of these things has to be due to a directing (nonhuman) intelligence of some kind.”
The kind of teleology that Aquinas describes above is elaborated upon by Christian philosopher Edward Feser. In Aquinas: A Beginner’s Guide, Feser states:
“A struck match generates fire and heat rather than frost and cold; an acorn grows into an oak rather than a rosebush or a dog; the moon goes around the earth in a smooth elliptical orbit rather than zigzagging erratically; the heart pumps blood continuously and doesn’t stop and start several times a day; condensation results in precipitation which results in collection which results in evaporation which in turn results in condensation and so forth. In each of these cases and in countless others we have regularities that point to ends or goals usually totally unconscious, which are built into nature and can be known through observation to be there whether or not it ever occurs to anyone to ask how they got there. In particular, one can know that there are these ends, goals, purposes in nature whether or not it ever occurs to anyone to consider the purposes, or even the existence, of a designer of nature.”
However, I do not find Aquinas’ 5th way to be a very persuasive argument for God’s existence. While Aquinas may be correct that there are uniform patterns in nature, it does not follow that these patterns are similar to how “the arrow is shot to its mark by the archer.” That kind of teleology reflects the design of a rational agent. The natural patterns that Feser described above, however, are not the same.
As philosopher André Ariew (“Platonic and Aristotelian Roots of Teleological Arguments,” pg. 17) explains:
“Aquinas exemplifies the melding of two teleologies whereby regularity of pattern is offered as evidence of design. As Ron Amundson so aptly puts it, “In Aquinas’ time it was easy to move from always acts for an end, and thence to achieves the best result” (Amundson 1996: 16). The distinguishing Aristotelian feature is the move from ‘always acts the same’ to ‘acts for an end’. The extra inference is Platonic and explains why the end ‘achieves the best result’.”
As Ariew explains, the kind of teleology that Aquinas provides in the 5th way only points towards (II) “teleology pertaining to natural organisms,” and does not provide the (I) “agency-centered teleology” that would point towards a rational agent–such as God. As such, I do not find Aquinas’ 5th way to be a very persuasive argument for God’s existence.
The first three of Aquinas’ Five Ways do not fare much better. For the 1st way, Aquinas states:
“The first and more manifest way is the argument from motion. It is certain, and evident to our senses, that in the world some things are in motion. Now whatever is in motion is put in motion by another … But this cannot go on to infinity, because then there would be no first mover, and, consequently, no other mover; seeing that subsequent movers move only inasmuch as they are put in motion by the first mover; as the staff moves only because it is put in motion by the hand. Therefore it is necessary to arrive at a first mover, put in motion by no other; and this everyone understands to be God.”
First, for a rebuttal to the kind of successive addition argument that Aquinas is using above, to argue that an infinite regress would be impossible, I recommend philosopher Graham Oppy’s “Time, Successive Addition, and Kalam Cosmological Arguments.”
However, even if Aquinas were correct that an infinite regress is impossible, and that there must be a first mover, this is not a persuasive argument for God’s existence. The reason why is that such a first mover does not need to be a rational agency. If something impersonal and non-rational was the first mover of motion in the universe, I think it would very strange to call such a thing “God.” I need evidence of (I) “agency-teleology” to believe in God, and Aquinas’ 1st way provides for it even less than his 5th way.
For the 2nd way, Aquinas states:
“The second way is from the nature of the efficient cause. In the world of sense we find there is an order of efficient causes. There is no case known (neither is it, indeed, possible) in which a thing is found to be the efficient cause of itself; for so it would be prior to itself, which is impossible. Now in efficient causes it is not possible to go on to infinity, because in all efficient causes following in order, the first is the cause of the intermediate cause, and the intermediate is the cause of the ultimate cause, whether the intermediate cause be several, or only one. Now to take away the cause is to take away the effect. Therefore, if there be no first cause among efficient causes, there will be no ultimate, nor any intermediate cause. But if in efficient causes it is possible to go on to infinity, there will be no first efficient cause, neither will there be an ultimate effect, nor any intermediate efficient causes; all of which is plainly false. Therefore it is necessary to admit a first efficient cause, to which everyone gives the name of God.”
As an initial observation, I think that Aquinas’ argument that nothing can be the efficient cause of itself may be a case of special pleading, since Aquinas does not seem to have a problem with God as the “first efficient cause,” which apparently has no other efficient cause then itself. I suppose you could say that God is “uncaused,” but why is there nothing else that could be the same? Seems a bit like a double-standard to me…
Likewise, as Graham Oppy (Arguing About Gods, pg. 99) points out:
“The most obvious difficulty with this argument is that it is invalid. The strongest conclusion that could be drawn … is that there are first causes, that is, that there are causes of existence that are not themselves caused to exist. There is nothing in the premise that justifies drawing the conclusion that there is exactly one first cause.”
Regardless, though, Aquinas’ 2nd way has the same problem as the 1st. Even if we buy his argument about a “first efficient cause,” it does not follow that this would be an agent cause. What we need is evidence of a rational agent, not merely that there might be a first efficient cause. If the first efficient cause is impersonal and non-rational, then I see no reason to call it “God.”
For the 3rd way, Aquinas states:
“The third way is taken from possibility and necessity, and runs thus. We find in nature things that are possible to be and not to be, since they are found to be generated, and to corrupt, and consequently, they are possible to be and not to be. But it is impossible for these always to exist, for that which is possible not to be at some time is not. Therefore, if everything is possible not to be, then at one time there could have been nothing in existence. Now if this were true, even now there would be nothing in existence, because that which does not exist only begins to exist by something already existing. Therefore, if at one time nothing was in existence, it would have been impossible for anything to have begun to exist; and thus even now nothing would be in existence — which is absurd. Therefore, not all beings are merely possible, but there must exist something the existence of which is necessary. But every necessary thing either has its necessity caused by another, or not. Now it is impossible to go on to infinity in necessary things which have their necessity caused by another, as has been already proved in regard to efficient causes. Therefore we cannot but postulate the existence of some being having of itself its own necessity, and not receiving it from another, but rather causing in others their necessity. This all men speak of as God.”
This argument is a bit more complex, but what Aquinas is getting at is the idea of contingency. To simplify and explain Aquinas’ argument, I will quote Graham Oppy’s summary in Arguing About Gods (pp. 103-104):
“The core of the Third Way appears to have much the same kind of structure as the first two ways. However, there is an interesting–and much discussed–supporting argument for the claim that there are necessarily existent beings that is not paralleled by supporting arguments for the claim that there are things in a process of change, or things whose existence has an efficient cause. According to standard translations, the argument of the Third way is something like this:
1. There are contingent things.
2. If an existent thing is contingent, then there was a time when it did not exist.
3. (Therefore) If everything is contingent, then there was a time when nothing existed.
4. Something that does not exist can be brought into existence only be something that already exists.
5. (Therefore) If there was a time when nothing existed, then nothing exists now.
6. Something exists now.
7. (Therefore) Not every existent being is contingent.
8. A necessary being may or may not owe its necessity to something else.
9. The series of necessary beings that owe their necessity to something else does not regress to infinity.
10. (Therefore) There is a necessary being that does not owe its necessity to something else.”
All of that is quite a mouthful, but it still provides no persuasive evidence for God’s existence. Even if there must be a “necessary being,” which owes its necessity to nothing else, it does not follow that such a thing would be a personal, rational agent. As such, Aquinas’ 3rd way still provides no evidence for (I) “agency-centered teleology.”
What I will say about the first three of Aquinas’ Five Ways, along with the 5th way, is that they are based on empirical evidence. Motion, causation, contingency, and uniformity are things that we can generally infer from the empirical observation of our universe. However, they do not reflect the kind of behavioral and artifactual goal-orientation that is characteristic of a rational agent.
We can identify such rational goal-orientation in miracles, however. For example, if a limb were to regrow after someone prayed to a specific god (and only that god), we could infer that the action was behavioral and undertaken for the sake of some rational purpose. If the Red Sea were to part, specifically to allow a group of people to pass through, we could infer that the action was artifactual, in that the it achieves a very precise effect and not other effects. If a man turned water into excellent wine for a wedding, we could infer both that the action was behavioral and done for a certain purpose, and we could even link the miracle to a specific agent–the man performing the miracle.
The same is true of prayer studies. If a successful study were conducted showing that praying to a specific god cured illnesses–and only praying to that specific god, with other religions having no such effect–that would be excellent empirical evidence for some sort of rational, intelligent intervention. It would reflect the activity of an intentional agent specifically answering only certain kinds of prayers. However, as philosopher Stephen Law pointed out above, no such successful studies exist. It is not that such evidence couldn’t exist, in principle, but we simply live in a universe that reflects no such divine intervention from a rational agent.
We only have Aquinas’ 4th way left to discuss, and, strangely, I think that it might carry more weight as an argument for the existence of God. For the 4th way, Aquinas argues:
“The fourth way is taken from the gradation to be found in things. Among beings there are some more and some less good, true, noble and the like. But “more” and “less” are predicated of different things, according as they resemble in their different ways something which is the maximum, as a thing is said to be hotter according as it more nearly resembles that which is hottest; so that there is something which is truest, something best, something noblest and, consequently, something which is uttermost being … Now the maximum in any genus is the cause of all in that genus; as fire, which is the maximum heat, is the cause of all hot things. Therefore there must also be something which is to all beings the cause of their being, goodness, and every other perfection; and this we call God.”
This argument appeals to the gradation of normative properties–such as something being “good” vs. “better” vs. “best.” Aquinas argues that, since the maximum of any genus is the cause of all in that genus, then God–the maximum of goodness–must be the cause of goodness in things.
Now, why do I think that this may be a stronger argument? The reason why is that I do tend to view normative properties–such as “good” and “bad”–as reflecting the preferences and desires of rational agents. As I argue in my earlier essay “Normative Ethical Subjectivism,” for example, I think that all such normative properties are dependent upon the preferences of judgemental subjects. When I say that something is “good” or “bad,” therefore, what I really mean is that it is preferable or non-preferable according to the standards of some arbitrative observer. Likewise, as I argue “Teleological Vs. Deontological ‘Oughts’,” I think that the only kind of normative imperatives that can be valid are those that refer to teleological goals. I also recently discussed these kinds of “hypothetical imperatives” in my essay “Are All Norms Moral Norms?”
The problem with Aquinas’ argument, however, is that I do not buy his premise that “goodness” is an objective quality of an object that we can “observe” apart from an arbitrative subject. There is no such thing as as something that is “good”–in essence–in my metaphysics. As Brian Davies (Thomas Aquinas’s Summa Theologiae: A Guide and Commentary, pp. 43-44) points out:
“The observational premise of the Fourth Way might strike some readers as not being any such thing. For do we observe that some things are more or less good, true, noble, and so on? … To understand the Fourth Way one needs to realize that Aquinas regularly takes being, truth, and goodness to be related in a serious way. For him, something that has being is always to some extent good.”
And here I simply disagree with Aquinas. I do not think that “being” is always to some extent “good.” Instead, I think that things are only “good” if they serve the preferences of some arbitrative subject. And, I see no such normative values in nature apart from what humans assign them.
Regardless, we are back to how we define and conceptualize normative properties–like morality–just as I discussed at the beginning of this essay. And, as I explained above, I do not find theological arguments that rest on these kinds of issues to be persuasive, because they are not empirically testable. Instead, these arguments boil down to how define certain kinds of ontological properties. I do not take it as a valid premise that we “observe” goodness in nature, like Aquinas, apart from human preferences, because of how I define normative value. There is no way to resolve this dispute, but to offer new definitions, and that is not the kind of empirical evidence that I am looking for with God.
As such, I do not see the gradations of “goodness” in being as something that needs to be explained by God, or anything else, to begin with, leaving the 4th way as another ineffective proof of God’s existence.
We saw above that there is good reason to think, theologically-speaking, that there could be empirical evidence of God’s existence. Even if God cannot be empirically observed directly, theologians like St. Thomas Aquinas have agreed that we can still study a cause through its effects. This kind of logic has likewise been used by atheists for years, such as philosopher Stephen Law. If I were to see empirical evidence of God’s effects, then I would be far more inclined to believe in God’s existence.
However, to discern the existence of a rational agency as a cause–such as God–there needs to be evidence of (I) “agency-centered teleology.” This kind of teleology is behavioral and artifactual, rather than the formal and functional features of (II) “teleology pertaining to natural organisms.” As I also argued above, the teleological argument that Aquinas makes in his 5th way is an unpersuasive argument for God’s existence, since Aquinas conflates the (II) Aristotelian teleology seen in the uniformity of natural processes with the arbitrative and agency-centered characteristics of (I) Platonic teleology.
Aquinas’ 1st, 2nd, and 3rd ways are not persuasive, because they do not provide evidence of (I) Platonic teleology, either. Simply because there must be a first mover to put things in motion, or a first efficient cause to start other efficient causes, or a necessary being upon which contingent things are dependent, does not prove that any of these “first movers” or “first causes” or “necessary beings” are rational agents.
Aquinas’ 4th way depends on an ontological understanding of normative properties, such as “goodness,” that I simply do not agree with. Such a dispute, however, cannot be solved empirically, but solely through how we define normative properties. And, as I explained above, any argument for God that boils down to how we define ontological attributes like this will not persuade me. If you want to convince me that God exists, you will have to show me empirical evidence.
Such empirical evidence could exist and be provided. I have argued that miracles would be a perfect example. However, I have also argued in my essay “History, Probability, and Miracles” that we currently have no succesful study for such phenomena. Philosopher Stephen Law has pointed out the same about prayer studies above. Empricial evidence for such rational agency simply does not exist, and instead we only observe a universe governed by impersonal, non-rational, and non-mental forces, just as metaphysical naturalism predicts. But, if such empirical evidence did exist, I would be far more inclined to believe in the existence of God.
But, at the very least, let’s stop pretending–as many religious apologists do–that there could be no evidence that would ever persuade an atheist of God’s existence. Let’s also stop claiming that religion answers “different questions” that science cannot. There are many kinds of religious claims that could be empirically verified–miracles, prophecy, and answered prayers are just a few.
The arguments of theologians like Thomas Aquinas, however, simply do not provide such empirical evidence, because they do point towards any rational agency–like God. But that doesn’t mean that there is no evidence that could ever persuade me of the existence of such a rational agency, in principle .
 Other theological arguments–beyond appeals to the evidence of miracles, prophecy, and answered prayers–that I think would provide logically valid evidence for God’s existence (which is not to say that I think they are sound) include:
- Irreducible complexity in biological structures: Although evolution explains quite nicely the apparent design of biological structures (as I explain here), if there were genuine irreducible complexity in biological structures, I think that this would provide evidence for intelligent design. Such evidence would suggest the artifactual intentionality of Platonic teleology, which would go much further towards suggesting the existence of God as a rational agency than the mere Aristotelian teleology appealed to in Aquinas’ 5th way.
- Cosmic fine-tuning: If it could be demonstrated not only that the universe had an “unmoved mover” or “first efficient cause,” but further that this initial force had designed the universe in a specific way, then I think that this evidence would suggest the artifactual intentionality of Platonic teleology. There is no evidence of such fine-tuning, however, that cannot be explained as illusory by current cosmological models (as I explain here). As it stands, simply arguing that there is an “unmoved mover” or “first efficient cause” (if such a thing exists at all) does nothing to suggest that this initial force would be a rational agency, like God. I have also discussed the arguments of philosopher André Ariew (“Platonic and Aristotelian Roots of Teleological Arguments”) above, who explains that Aristotelian teleology alone does not demonstrate that our cosmos was intelligently designed.