How to Argue that God Exists

Written by: Michael Lucana

This is an exploration of Saint Anselm of Canterbury’s Ontological Argument, an argument which aims to prove the existence of God. The goal of this article isn’t to prove whether or not Anselm got it right, but to get a better understanding of what it means to have a philosophical dialogue about faith by breaking down how Anselm tries to get us to agree with him. I will try to stay away from using overly technical philosophical vocabulary where I can, but there are many aspects of Anselm’s argument that will require more than just broad and sweeping generalizations.

I have to admit, I’ve always found Saint Anselm’s Ontological Argument quite compelling. Not necessarily because I buy into it, mind you, but more because of how much it aspires to. Here is an argument that tells you without reservation that not only does God exist, but that it can be proven. Any way you slice it, that’s a pretty damn bold claim to make right there. Even if I don’t agree with the argument right away (more on that later), I just gotta know, how did you come to that conclusion? Let me in on the secret of your headspace Anselm, enlighten me.

And I’m not the only one who’s found the Ontological Argument compelling either. Ever since Anselm came up with it, back in the 11th Century, it has resurfaced again and again, taking on different forms, but ultimately amounting to the same thing, proof that God necessarily exists. In fact, even today you can find numerous videos online that will show you, using some version of the Ontological Argument, that yes God exists. By that same token, you will also find many videos that will argue the opposite and that there’s something just not right with Anselm’s argument.

So what am I going to do here? Am I going to show you that actually yes, Anselm’s reasoning is super bulletproof against any objections? No. Am I going to show you that Anselm was wrong? Not really. I’m just going to show how Anselm thought he was right, how he argued for the claim, “God exists.” And showing this really involves trying to understand the reasoning that Anselm used to get to his conclusion.

You Gotta Have Faith?

Anselm’s Ontological Argument can be found in a short work entitled Proslogion. The way Anselm presents it at the start of this work, he already believes in God, he’s already got faith. But now he’s trying to use his understanding to rationally work out his beliefs.

This…seems circular at first sight. After all, if I already have faith, that is, if I already believe that God exists, then can you really trust the conclusion I come to, that God exists? We would rightly be suspicious of someone’s conclusion that x was the case if they had started their argument with “I believe that x is the case.”

But when we actually get to inspecting Anselm’s Ontological Argument, we are going to find that, he doesn’t argue from the premise that he believes that God exists. Actually, he starts by arguing from the premise that God does not exist. Basically, he’s going to try to argue for the existence of God from what he believes to be an atheistic vantage point.

The Passage in Question

Alright well, let’s take a look at the passage in question, the one that all the hubbub is about. It’s the second chapter of the Proslogion. It’s an incredibly short chapter, so short that I included the whole thing below:

Truly there is a God, although the fool has said in his heart, There is no God.

AND so, Lord, do you, who do give understanding to faith, give me, so far as you knowest it to be profitable, to understand that you are as we believe; and that you are that which we believe. And indeed, we believe that you are a being than which nothing greater can be conceived. Or is there no such nature, since the fool has said in his heart, there is no God? (Psalms xiv. 1). But, at any rate, this very fool, when he hears of this being of which I speak –a being than which nothing greater can be conceived –understands what be hears, and what he understands is in his understanding; although he does not understand it to exist.

For, it is one thing for an object to be in the understanding, and another to understand that the object exists. When a painter first conceives of what he will afterwards perform, he has it in his understanding, but be does not yet understand it to be, because he has not yet performed it. But after he has made the painting, be both has it in his understanding, and he understands that it exists, because he has made it.

Hence, even the fool is convinced that something exists in the understanding, at least, than which nothing greater can be conceived. For, when he hears of this, he understands it. And whatever is understood, exists in the understanding. And assuredly that, than which nothing greater can be conceived, cannot exist in the understanding alone. For, suppose it exists in the understanding alone: then it can be conceived to exist in reality; which is greater.

Therefore, if that, than which nothing greater can be conceived, exists in the understanding alone, the very being, than which nothing greater can be conceived, is one, than which a greater can be conceived. But obviously this is impossible. Hence, there is doubt that there exists a being, than which nothing greater can be conceived, and it exists both in the understanding and in reality.

Okay, well…there’s a lot to unpack there. Even I’ll admit that. If you read all that and instantly understood every aspect of it, that’s great. If that wall of text is just screaming to you “Go no further!” don’t, worry about it. I first read this argument over ten years ago and even I still have to tread carefully when I rehearse it, but there is a way to to get through it.

To begin with, we won’t immediately worry about the content of the argument, what the argument is trying to say. We’re not gonna worry about how to wrap our heads around “that which nothing greater can be conceived” just yet. If we don’t buy into theism, we’re not gonna get offended that we’re being called “fools” for doubting the existence of God. No, what we want to get clear about first of all is the structure of the argument, how it thinks that it’s going to show us that the conclusion it’s trying to get at is true.

Reductio ad Absurdem

The Ontological Argument is fundamentally a Reductio Ad Absurdem argument. What this means is that Anselm isn’t really going to try to convince us that the claim (God exists) he’s arguing for is correct straight away. What he’s going to do first is show us that holding the opposite view (God doesn’t exist) leads to a conclusion that is self-contradictory.

Typically a Reductio Ad Absurdem doesn’t need to much to get going. If I’m going to show that someone’s belief leads to a self-contradictory conclusion I really just need the following:

(P) The belief that is to be refuted. This is the claim that my opponent is holding and I’m going to show leads to a ridiculous conclusion.

(Q) Another belief that my opponent also holds that is true, or that we both agree is true at least. There doesn’t just need to be one of these, there can be a whole bunch of them, but at minimum at least one is sufficient to get us to where we want.

Conclusion: (P & not-P) A conclusion that is inferred from P & Q that is obviously absurd because it involves the belief that P is both true and not true.

Let’s take a look at a Reductio Ad Absurdem argument that has slightly lower stakes than the existence of a cosmic creator to get a firm grasp of it:

(1′) David believes that it’s not raining right now.

(2′) David also believes that when the grass is wet, it is because it is raining. This is something David and I can agree on at least.

(3′) Well, you know what, the grass is wet when I look out the window. David looks out the window and notices that yes the grass is in fact wet.

(4′) David then comes to the conclusion that it is both not raining (from 1) and it is also raining (from 2 ‘& 3’).

Okay, there’s something obviously wrong with that, right? I mean, it can’t be both raining and not raining at the same time. We both agree that wet grass is a sign of rain and there is currently wet grass so it must be raining. Clearly David is wrong in believing that it’s not raining. But he chooses to conclude that it is both raining and not raining. Most of us would immediately see it as absurd if anyone continued to insist that there was nothing wrong with maintaining the conclusion (4′) David had come to. Foolish would probably be one of the nicer things they would get called.

In the same way that David would get called a fool for sticking to his guns that it is both raining and not raining at the same time, Anselm thinks that the atheist who says to himself that “there is no God,” is bound for a similar sort of absurd conclusion. Now let’s take that wall of text that confronted us earlier and see how it it fits within the structure of a Reductio Ad Absurdem argument.

Breaking down the Argument

To begin with there are three premises that Anselm supposes can be agreed upon by everyone. They are the following:

(1) A definition of God: God is that than which nothing greater can be conceived. For brevity, let’s just say that God is Q. There is a lot to be said about why Anselm thinks this is a good way to define God, but for now let’s just take it for granted that when we’re talking about God, whether or not we think He exists, we’re usually thinking of an ultimate sort of being, one which surpasses any other being in power, knowledge, etc. Therefore, if it’s the ultimate being, it’s going to be greater than any other being we can conceive of.

(2) God’s existence in reality is conceivable. This just means that if we’re talking about God, we can imagine the idea of an ultimate being existing. Really, if we’re having a conversation about God, even a hypothetical God, we’re kind of already doing this.

(3) To exist in reality is better than existing in thought only. There’s two ways we can take this claim which Anselm thinks is also something that everyone can agree on.

The first way is, we can look at it as saying something like “It’s better to exist than to not exist,” which, I think most of us translate to, “a delicious beer is nice to think about, it’s much better if that beer is actually existing in reality and is here physically in my hands!”

That’s not quite what Anselm is getting at here. There’s another way of looking at this and it is through the lens of Platonic Metaphysics. Without going into too much detail we can spell it out this way:

“If something exists in my thinking only, like an idea of what social justice is, then it has some reality but of a very minimal sort because it’s only in my thoughts. But if I see justice being enacted in my society, then it not only has more reality but is better than if it had stayed in my thinking. But even further, Justice must be a real objective thing that exists everywhere and for all time, otherwise what standard of justice am I comparing the justice being enacted in my society to? So, the existence of Justice, this universal sense of it, must be superior to it merely existing in my thoughts. That must be real existence, and better even, because it never changes, because it is true Justice.”

That’s kind of Platonic Metaphysics in an incredibly compressed nutshell. It assigns a higher degree of existence to things which are universal in nature, like Justice, Equality, Goodness. They don’t have to be something we can see and touch either, because, as this mini-argument shows, to be truly real, to really matter, things don’t need to meet that requirement. In fact, according to Platonic Metaphysics, being real in the physical sense is actually kind of a step down. But that is a longer story. Now, with this in mind, we can kind of see in what sense Anselm thinks it’s better to exist than to not exist. We’ll have more to say about this particular premise later but for now let’s just accept it at face value.

(4) The Atheist’s Claim: God does not exist. Alright, so this is the claim that Anselm is going to try to show leads to an absurd conclusion. Even though it look like one claim, it’s actually a combination of sorts of two different claims:

(4A) God exists in the mind. The atheist is thinking about about God, or at least thinking about the concept of God. So the atheist is already kind of conceding that God, defined as Q, is something we can think about, make hypotheses about, etc.

(4B) God does not exist in reality. But, the atheist also claims, existing in the mind is as far as God gets to being real.

Alright, these are Anselm’s main premises. Next, let’s take a look at how he uses these to show that the atheist is self-contradictory in their belief.

Inferring to Absurd Conclusions

(5) If God existed in reality, He would be greater than if he only existed in the mind. This inference follows from (3) and (4). It’s merely saying “Hey, of course it would be better to exist in reality than to exist in thinking only. But I don’t think God exists in reality, only in my mind, so I guess if He really did exist in reality, he’d probably be greater than I thought.”

(6) It is conceivable that there is a being greater than God. This inference follows from our newly created claim (5) and (2) from our original list of premises. This is where we start to get a sense of where Anselm is intending to trip up the atheist. Why? Because the atheist has already claimed not only that it would be better to exist in reality, but that God, being just limited to being thought about, doesn’t fit into the category of things which exist in reality. In fact, God is one step below reality. But this means of course, if we’re sticking to Platonic Metaphysics, that there’s now gotta be something else, something which has more reality than God since we just brought God down a notch. Platonic Metaphysics is a pyramid of sorts, and something’s got to be on top.

(7). It is conceivable that there is a being greater than that which has been defined as Q. Back in (1) we had defined God as Q, but apart from that claim we had also come to infer in (6) that if God wasn’t at the top of the metaphysical pyramid, something else must be. From (1) and (6) we end up with the conclusion that there must be something greater than that which we have already defined as that than which nothing greater can be conceived. But this is absurd.

The chart I created above roughly conveys the atheist’s alleged absurd line of thinking that Anselm is trying to map out. Green items are our original unchallenged premises (1-3), the yellow item (4) is the premise that is also assumed but we want to challenge. The grayish items are the new inferences (5-6) that are made from the unchallenged premises. The red item (7) is the absurd conclusion that is derived from what came before it. When we trace our way backwards, we find that the only premise that could have caused the absurd conclusion is the one we marked as yellow (4) , the claim that “there is no God.”

Since we had broken down (4) into two smaller claims, we can take a look them individually and see very quickly that it is (4b) that led us to the absurd conclusion. Right away, we’re supposed to conclude, along with Anselm that (4b) must be false if we are to avoid absurdity, and just like that, (4b) is transformed into it’s opposite, “God does exist in reality.” And this is how Anselm concludes that yep, God exists.

So That’s it God Exists?

Well, that’s completely up to you really. After all, even Saint Thomas Aquinas (no theological lightweight), who lived around a hundred years after Anselm had a problem with Anselm’s attempt here. And, I’ve always found Aquinas’ counter-objection to kind of line up with my own thinking on the matter even though I have to admit, I still have much work to do in understanding the nuances of it.

On the one hand, Aquinas didn’t think human beings could work out the existence of God from concepts alone, which is pretty much what Anselm is doing. Aquinas was also an empiricist of sorts, and it is this empiricist way of looking at things that roughly (very roughly) lines up with how most of us think about what existing means in our day and age. For most of us, you have to demonstrate that something exists by appealing to empirical evidence, evidence gathered from your senses. For Aquinas, something like God can’t be reasoned into existence merely from analyzing our concepts about God, because it isn’t really clear straight away (to humans anyways) that those concepts do have greater reality than the ordinary things we experience in the world. For Aquinas, we have to take a look at what facts we have about the world, about what we immediately take to be “real” things and build up a theory of God in that way. So, the search for the existence of God takes on a character that seems more like scientific research as we think about it nowadays.

So right away we can see how those Platonic Metaphysics that undergird Anselm’s argument aren’t a given. Not everyone intuitively buys into the reality of abstract things like Justice and Goodness, or even God, because, if we can’t see it or touch it, or sense it in any way, what justification do we have for saying it has more reality than our thoughts? And if we don’t buy into the existence of abstract things, then we never really fall into the atheist’s alleged predicament, as Anselm presents it.

But this doesn’t mean that Aquinas rejected the existence of God either. Faith was just as important to him as to Anselm. But, he had his own ways of getting to the same conclusion without strictly resorting to Platonic Metaphysics.

I’m not going to run down all of the other counter-arguments against Anselm. Honestly there are far too many, and that would require far more philosophical analysis than I’m willing to write about in this article. Not to say that they’re not worth studying and appreciating either. But what I want to be clear about is that you don’t need to buy into Anselm’s argument, I certainly don’t. I’ve already said that Aquinas, a Christian, who philosophized about a hundred years after Anselm, had problems with this argument too. In fact, not even all of Anselm’s contemporary fellow Christians bought into it. There’s a very famous letter by an Italian monk by the name of Gaunilo where he makes a very intuitively compelling argument against Anselm’s reasoning. And Anselm even wrote back to Gaunilo where he attempted to clarify some of the finer points of his argument.

And this is honestly one of the biggest takeaways for me, that even though Anselm is up front at the beginning of the Proslogion that he believes in God, that doesn’t stop him from letting rationality also have it’s say about the coherence of his beliefs. After all, if he wasn’t open to rationality, to thinking about his beliefs through the lens of what he takes to be logical reasoning, why would he bother to respond to Gaunilo the way that he did? He could have simply said, “Well, God exists so your argument against my proof means nothing.” No, he tries to clarify his thinking about the matter, and explain his reasoning. In short, he attempts to have a rational dialogue.

In fact, even though he uses the pejorative term “fool” for the atheist in his argument, notice that he doesn’t merely say “The atheist is wrong.” Well, that’s his conclusion, but still. He tries to wrap his head around (whether successfully or not) how an atheist would conceive of that claim that “God does not exist.” Then he still doesn’t just say, “The way the atheist is conceiving of that claim is wrong.” He still tries showing how, rationally, the atheist’s belief just doesn’t work out. And this takes the form of an incredibly dense argument, as we’ve just seen. The atheist isn’t just going to believe that God exists like Anselm, so Anselm has to use a different method, he has to speak to the atheist in a language that circumvents dogmatic authority. And that language, within the Proslogion, is rational in nature.

And this is what is ultimately most important to me and, I think, should be important to everyone (whether atheist, theist, or somewhere in between). If we’re gonna get by in this world together, in any attempts at talking about faith or God or anything else, we have to make an honest attempt at rational dialogue coupled with a genuine understanding for one another. Anselm’s argument might be shaky in many respects, but the spirit in which he attempts it is not, at least the way I see it.

If the topic of this discussion seems like something you would like to investigate further on your own, please feel free to contact me in order to schedule a Philosophical Counseling session. All Philosophical Counseling sessions are conducted via Zoom and single-person. If you are located in the San Francisco Bay Area and are interested in conducting an in-person session, please get in touch with me via e-mail. For any other inquiries contact me via e-mail as well.