Alexander Pruss says arguments for the existence of God can be separated into the following categories.
- Purely logical.
- Partially empirical.
The purely logical arguments are the ontological arguments. (I propose a pseudo-ontological argument here.)
The partially empirical arguments can be broken out into categories of their own.
- Very specific data point (such as miracles = argument from miracles)
- Less specific data point (such as complex life = arguments from design)
- Very general data point (such as change, contingency, etc = cosmological arguments).
Most of my work has been on the latter most category, starting from some general fact of experience (say, contingency), deducing this or that metaphysical conclusion from it (that not everything can be contingent), and then reasoning from that conclusion to the existence of God (that everything contingent depends upon subsistent existence itself, which is God).
Aquinas’s arguments are empirically general, as well. His argument from change, for example, begins with an experience (i.e. “that change occurs”) that no non-philosopher would think to deny, and that cannot be overturned by further empirical discovery. Aquinas then analyzes change as the reduction from potentiality to actuality — an analysis that must hold less we deny the reality of change altogether and collapse into the absurdity of Parmedeanism. From there a further conclusion can be reached via the principle of non-contradiction: that because nothing can be both potential and actual in the same aspect, whatever is moved from potential to actual must be moved by something already actual. The critical and often overlooked aspect of Aquinas’s argument from change is to interpret it metaphysically and existentially; that is, when concerning what moves any potential thing to have actual existence at any moment. In other words, the causal property under examination just is the actual existence (or esse) of a thing which itself need not exist, because of the real distinction between what that thing is, and that the fact that it is. With me so far?
Finally, we rule out an infinite regress of causes in the order of existence, which in the type of causal series under consideration — specifically, what’s known as a per se causal series where the members of the series do not possess the causal property in question in virtue of what they are, but rather in virtue of something else — we can conclude to a first (read: primary) member, or that which does possess the causal property in question in virtue of what it is. If we deny a primary member in a per se causal series we deny the existence of the series altogether – a contradiction of fact results.
Think about it this way. If everything which exists (call this The Totality of Reality) received existence from something beyond itself, then The Totality of Reality would receive existence from something beyond itself. But by definition there is nothing beyond The Totality of Reality. Anything which exists is included in The Totality of Reality. So not *everything* can receive existence from beyond itself, otherwise The Totality of Reality would be dependent upon something beyond itself to exist. But since there is nothing that could grant existence to The Totality of Everything, nothing would exist. In other words, The Totality of Reality would be something which exists only conditionally (that is, only if conditions beyond itself were fulfilled), but since we’re talking about The Totality of Reality this means it could never have its conditional requirements for existence fulfilled because there is nothing beyond The Totality of Reality to fulfill them! Thus, to deny a primary member in the order of existence is to deny that anything exists at all, which is a contradiction of fact. (Some have argued it is also a logical contradiction to say nothing exists, but we needn’t go that far.)
In short, not everything can have a cause of its existence, because beyond everything (and whether everything includes a finite or infinite collection is irrelevant) there is nothing that could cause anything.
So there must be something — at least one thing, though perhaps multiple things — which exist in virtue of what they are and not in virtue of something beyond itself. Something which stands independently and is not in need of a cause because whatever this something is must be identical to existence itself; if not, then it would need existence imparted to it.
But so say something is identical to existence itself is really to say there is something which is “pure actual existence existing through itself.” Why so? Simply because if there were any element, factor, part, or dimension (etc) to this reality that was different from “pure existence existence through itself” then, by definition, that element, factor, part, or dimension (etc) would NOT be “pure existence existence through itself” and would therefore be contingent and in need of a cause. But anything in need of a cause in the order of existence cannot be the primary member in the causal series concerning existence, for reasons stated earlier. So only that which is “pure actual existence existing through itself” can be the primary member in the most fundamental causal series of all — that is, the causal series upon which all other causal series piggy back, because every other possible causal series (whether involving motion, heat, you name it) must first assume the existence of the series in question and the members thereof.
Furthermore, because this bedrock reality must be a pure act of existence, existing through itself, and is not susceptible to differentiating features, it must be uniquely unique. It is one and only one. Since to have multiple instantiations of something requires the possibility of differentiating features (otherwise the proposed multiple instantiates are actually the self-same reality), but pure actual existence existing through itself is not susceptible to differentiating features, since anything that is different from pure actual existence existing through itself is by definition NOT pure actual existence existing through itself and thereby a caused, contingent, or dependent reality. Apologies for the abstract language, but hopefully the point is clear: There is, and can only be, one God.
At this point you might think I’ve gone too quick in calling pure actual existence God, and perhaps you’re right. But that’s only because we haven’t run a complete analysis on what it means to be pure actual existence existing through itself — an analysis I run in my eBook How to Think About God — showing how pure actual existence existing through itself leads ineluctably to omnipotence (the ability to bring about all logically possible realities), omniscience, omni-benevolence, trans-physicality, and all the rest. I will not strain the reader’s patience with a repeat of that analysis here, but instead will simply gesture in the direction of my eBook for anybody who’s interested in following the argument all the way through. I’ve already gone into more detail than I’ve planned, but what can I say? I get excited about this sort of thing.
Two related videos, linked below.
Back to our original point, then.
I don’t think all arguments for God’s existence are good – but I will not discuss the bad arguments. Instead I am simply interested in evaluating arguments that I think do serve some useful purpose and getting straight on what that purpose is (and isn’t) and what our expectations should (and shouldn’t) be.
Though I consider myself broadly a Thomist, I tend to be more sympathetic to theistic friendly arguments many Thomists are critical of. Again, you can click the link at the beginning of this article to see what I think of contemporary ontological arguments. My position is that with recent developments in the logic of possibility, at least some of these “possible cause” arguments are sound, though they aren’t exactly “purely logical” anymore, since we do begin with some general fact of experience. Because of this, I say Thomists should be more willing to re-evaluate these pseudo-ontological arguments even if they have been skeptical of previous Anselmian and/or Cartesian formulations, as I have been, as well. I will, however, say the family of ontological arguments are next to useless apologetically when engaging with laymen. Unless they’re trained philosophers, people will probably think you’re peddling voodoo.
But let’s discuss arguments from miracles and complexity.
Thomists are not necessarily committed to miracles happening, but since most Thomists are Christian, it would be rare to find a Thomist who denies the occurrence of miracles, especially since Christianity hinges upon the resurrection. But I suppose it is theoretically possible to be a Thomist and reject God’s miraculous intervention into the world. However, Thomists do not frequently argue from the occurrence of miracles to God, rather they establish a metaphysics which inevitably includes God and then show how miracles fit nicely into this account. I agree with this. The fact that miracles have seemed to occur and that we have considerable evidence in their favor — especially for the Resurrection, though I would add Fatima, as well — these are the sorts of occurrences I might expect if God exists, but not at all the occurrences I would expect if God did not exist. Theism thus offers better explanatory power and scope, whereas naturalism struggles mightily with attempting to explain away a multitude of well-evidenced miracle accounts. (Obviously the naturalist can explain some away, but I would argue he cannot explain all away.)
What I am hinting at above is often called a “cumulative case” where one makes an inference to the best explanation. For more on that approach, see my post on The Case for Religion (and Especially Catholicism).
On a popular level, arguments from miracles seem to sway people who are not resistant to God but are often laughed at by recalcitrant skeptics and cynics. Then again, I am not sure any argument, however plausible, is provided a fair hearing from people who have a deep pre-commitment to the non-existence of God. (That is often more a psychological issue than a philosophical one, I’m afraid.) But arguments from miracles are more concrete than the abstract philosophizing, so it doesn’t surprise me to see more people responding to miracle accounts than metaphysical demonstrations. I do, however, and from a philosophical perspective, believe it is better as a matter of procedure to “do your metaphysics” before making the case for any particular miraculous occurrence, especially since a person’s prior philosophical commitments will drastically affect how they interpret the evidence on the ground for any purported miracle, including the resurrection. Probably I would not have thought to give the historical case for Christ a fair hearing until I first convinced of God’s existence, but once I was convinced of God’s existence and goodness, the historical case was more than adequate to convict me, if only because it is so befitting of an all-good, all-loving God in response to a world suffused with sin. The point is worldview considerations carry tremendous weight into interpreting empirical claims.
My evaluation of very specific empirical arguments for God and specifically arguments from miracles is these are best served as part of a confirmatory-cumulative case after the prior metaphysics of Classical Theism has been established.
Let us now then proceed to less specific data points, such as arguments from complexity. The argument from design has seen many iterations, from Paley to Behe. Some put Aquinas’s 5th way into this category, but that is a serious misunderstanding. Aquinas’s 5th way is a metaphysical argument grounded in essentialism and teleology, not complexity. So, let’s put that one aside. (I am also putting aside the metaphysical argument from compositeness, which I believe does move one from complexity to absolute simplicity and therefore classical theism.)
Design arguments in the contemporary literature (see here, here and here) are typically launched either from biology or cosmology. The latter would include much of the so-called Intelligent Design movement, especially our friend Dr. Michael Behe. The former would include any philosopher and/or scientist who argues from physical fine-tuning to transcendent creative intellect. These launching points are importantly different because if one proceeds from irreducibly complex molecular machines, say, to intelligent designer, there is still enough room to plausibly (though I don’t think probably) suggest something or someone other than God as the responsible intelligent agent. Aliens, perhaps. In other words, you can’t move in an ironclad deductive process from irreducible complexity to the God of classical theism — at most, you just get some general inference to intelligent agency, whatever that is. Hence why Behe does not say “God did it” and that, coming from a scientific perspective, we can leave who the intelligent designer is/was completely open to further investigation. I think that is right, but that does not mean it is insignificant. That intelligence had any role to play is a serious existential threat to naturalistic neo-Darwinian theory, even if it doesn’t immediately conclude to Classical Theism.
Arguments from physical fine tuning leave considerably less room concerning who or what such an intelligent agent could be. (Generally, such arguments hold that it is either astronomically improbable, if not impossible, for the exceedingly delicate fine-tuning of the physical universe to be explained by anything other design, whether necessity or chance), For if we’re talking about an initial physical set up, it is hard to see how anything within the realm of physical reality could be responsible without inviting vicious circularity. Hence, if we are going to invoke intelligence at all to explain physical fine-tuning, that intelligence will have to be transcendent, which essentially gets you to God, even if not classical theism, per se. Again, not insignificant, even if it is not the complete account.
What do I make of these arguments? Well I take them to be pretty good so far as they go. The problem is most people put too much stock in their apologetic or metaphysical role. Behe — for example, and contrary to many of his critics — is insistent that his arguments should be seen as entirely empirical/scientific, and that he holds no particular philosophy of nature, nor is he trying to “prove” God’s existence or the truth of any religion. That people blast his position based on assumptions Behe not only doesn’t hold but would reject is just berating a strawman. So, when seen in their proper context, I am sympathetic with Behe’s critiques, and don’t believe his challenges — though admittedly limited in scope — have yet been effectively met. (See not only my previous podcasts with Behe, but his recent book Darwin Devolves, for more.)
Same with physical fine-tuning arguments. Understand their limited utility and be willing to accept that the underlying evidence could change, even if that seems exceptionally unlikely. This is why it’s essential to get your metaphysics straight before wading into these otherwise probabilistic arguments which hinge upon more specific empirical observations which could (in principle, anyway) be overturned by future discovery, whereas something so general as our experience of change or that contingent things exists is not a starting point that can be sensibly denied. Hence the metaphysical arguments launching from the most general aspects of human experience offer more confidence and security in their conclusion — and provides a more robust conclusion at that, given that they deliver the full suite of divine attributes — than the former.
In summary, I believe the partially empirical arguments which proceed from the broadest aspects of experience are the most philosophically demonstrative and metaphysically significant. (Such a category would include much of what Aquinas is up to, along with contemporary contingency arguments.) They are the most confident in their deliverances and render the most conceptual content in their conclusions. As a class, ontological arguments suffer from issues of symmetry breaking as regards the initial possibility premise, which I attempt to tilt in favor of theism by the argument linked above – that, I believe, is about the strongest we can make them. But again, their apologetic utility is slim.
Arguments based on more specific observations, whether physical fine tuning or irreducibly complex molecular machines are always somewhat less sure in their deliverances because the empirical facts could in principle change, even if we don’t believe there is a realistic probability of that happening. Still, it must be acknowledged as a potential shortcoming, at least for those looking for the strongest possible arguments. However, these shortcomings are often balanced out in a practical sense by the otherwise obvious attractiveness and intuitive nature that these arguments provide, whereas the more technical metaphysical demonstrations of Aquinas frequently fly over people’s heads because of their abstract form of argumentation.
As far as apologetic conversations go, I have found it helpful to let people decide where they’d like to engage, often by listing some or most the reasons I think God exists and more specifically how I see God as the best (if only possible) explanation for why anything contingent exists, why the universe began to exist and appears finely tuned for the emergence of intelligent life, why consciousness is irreducible to physical processes alone, why historical details support the Resurrection of Christ, and so on and so forth. In other words, why God provides the simplest and most powerful explanation of our human experience.