Alvin Plantinga’s Ontological Argument

Of all the arguments for the existence of God, this argument is perhaps the most controversial and confusing, but when understood correctly, Alvin Plantinga’s ontological argument is perhaps one of the strongest arguments in academia for the existence of God. Because this argument is prone to misunderstanding, a fair amount of groundwork must be laid first. I would ask the reader to tread through this blog carefully in order to not misinterpret what this argument is saying.

First of all, how is God defined? God is traditionally defined by theists as a Maximally Great Being (MGB). If something else was greater than God that being would be God, but the question to ask is what makes a being maximally great? For a being to be maximally great, it would have to be all-powerful, all-knowing, and morally perfect in every possible world (which is another way of saying it would have to exist necessarily). In other words, it would have to possess properties know as “Greater Making Properties” and it would have to possess these properties to their fullest extent. It is hard to imagine intrinsic values which could cause a being to be greater than that which these attributes already ascribe. These values encompass the complete sum of greatness. These values includes love, knowledge, power, etc. If a being possesses these attributes to their fullest extent, it is maximally great.

A Maximally Great Being would not only need “Greater Making Properties,” but it must also exclude “Lesser Making Properties” or properties which make it less good for a being to have. Such lesser properties include cruelty, ignorance, and weakness. If a being possessed any of these attributes, it would not be maximally great.

Thus, this is how God is defined for the argument: He is a Maximally Great Being who possesses the total sum of “Greater Making Properties” to their fullest extent, and He does not possess any “Lesser Making Properties.” Therefore, He is all-powerful, all-knowing, and morally perfect in every possible world.

But, what is a possible world? In philosophy, to speak of a possible world is to speak of a hypothetical scenario in which if the world was a certain way, things would have been that way. For example, unicorns do not exist in the actual world, but it is easy to conceive of a possible world in which unicorns do exist. It is also easy to conceive of a possible world in which horses do not exist. They could exist in some possible world, but not others. They don’t have to exist, but they do. These things would be known as contingent, and they include plants, minerals, animals, and even humans. Contingent things only inhabit some possible worlds.

Are there things which could not exist in any possible world? Yes, and these things are known as impossible. These things would include logical incoherencies and self-contradictions. Examples include a married bachelor, a square-circle, the shape of the color purple, or the smell of a mathematical equation. These things are logically incoherent, so one cannot conceive of them existing in any possible world. Therefore, these things exist in no possible world.

Are there things which must exist in every possible world? Yes, these things are known as necessary. These are things which are eternal and changeless. Some mathematicians believe that numbers fall into this category. To them, numbers are not created entities, but rather 2 is the number 2 purely out of the necessity of its nature; necessary things cannot not exist.

Where does God (or a MGB) fit into these categories? It depends on whether or not He exists. Many philosophers agree that if God exists, He would have to be a necessarily existing thing. According to the ontological argument, if God does not exist, then there must be something incoherent or logically impossible about a MGB. Why could not a MGB be contingent? Because of the characteristics of said MGB. A MGB would have to be all-powerful, all-knowing, and morally perfect in every possible world. A MGB would not match the description of a contingent being, and if it did, it would not be maximally great therefore failing to meet its own attributes given to a MGB.

Now, we get to the argument. This argument is a deductive argument meaning that if the premises are true, then the conclusion is necessarily true. Here is the argument:

1) It is possible a Maximally Great Being (MGB) exists.

2) If it is possible a MGB exists, then it exists in some possible worlds.

3) If a MGB exists in possible worlds, then a MGB exists in every possible world.

4) If a MGB exists in every possible world, a MGB exists in the actual world.

5) If a MGB exists in the actual world, then a MGB exists.

The argument contends that if a MGB possibly exists, then by the way possible worlds are understood, a MGB must exist in some possible worlds. If it is possible, it inhabits a possible world.

But, a MGB is not just a being which inhabits some possible worlds; it is a being which is necessary, so it must inhabit every possible world.

But, if a MGB exists in every possible world (and since every possible world would include the actual world), it must exist in the actual world.

But, if a MGB exists in the actual world, a MGB exists.

Convinced yet? That’s fine, neither was I. What’s important to remember is that the point of the argument is not to be convincing; the point is to be logically valid and true. As I said before, this argument is a deductive argument meaning if the premises are true, then the conclusion must be true regardless of how convincing the argument overall may seem. The pertinent question is whether or not the premises are true.

Believe it or not, the only controversial premise is premise 1. Premises 2-5 are uncontroversial because if premise 1 is true, the rest of the premises follow from the first premise, but is the first premise substantiated?

Well, it certainly seems that way. After all, if there is nothing incoherent about a MGB (therefore making it impossible), that means it is possible a MGB exists, and the rest of the premises follow. The opponent of this argument must not only show that God does not exist. They must show it is impossible for God to exist. In other words, they must show there actually is something incoherent about a MGB.

Have any of these attempts been proven successful?

One of the most common attempts to prove omnipotence (or being all-powerful) logically incoherent has been the omnipotence paradox. It’s often purported as follows: can God create a stone so heavy that even He cannot lift it? If He cannot create the stone or lift said stone, He is not all-powerful. Therefore, omnipotence is an impossible trait. The problem with this argument is that it presents a logical impossibility as a defeater for omnipotence when logical impossibilities are not hindrances to omnipotence because logical impossibilities are meaningless statements. To ask God (an all-powerful being) to create a stone so heavy even He cannot lift it is like asking God to create a square-circle or a married bachelor. They are in essence incoherent and therefore meaningless statements, so they are not hindrances to God’s power. It is important to remember that omnipotence does not mean God can do anything. Such a view is not advocated in the Bible, and this view has serious logical problems facing it.

If God being unable to do or create logically impossible things bothers the reader (particularly the Christian reader), I would phrase my response this way: the Bible states God cannot lie (Hebrews 6:18). Why is that? Because God (as defined in the Bible and in this argument) is a morally perfect being. To lie is a moral imperfection. Therefore, God cannot lie for if He did so He would contradict Himself. In the same way, God cannot act upon logical impossibilities because these are incoherent and meaningless statements, and I would certainly say God cannot do anything meaningless.

Another attempt to discredit the argument is to substitute a unicorn, Thor, or any other obviously fictional or ridiculous entity in the place of a MGB in the argument. It is using a parody of the argument in order to render it false. The problem with a majority of these parodies is they try and equate a MGB (which would have to be necessary) with something which is contingent. The problem with arguing for a maximally great unicorn is that a unicorn is an entity which would be contingent and therefore not exist in every possible world. Further, for many of these parodies, the ridiculous entity they try to use does not have any maximal values or any clear intrinsic values. A classic example is the monk Gaunilo of Marmoutiers who responded to the original ontological argument postulated by Saint Anselm of Canterbury with what he called a “perfect island.” Substitute a perfect island (or an island greater than which no island could be conceived) for a MGB and one can see the argument does not work according to Gaunilo; however, the problem with this objection to the ontological argument is two-fold: 1) an island is a contingent being, not a necessary one (as a MGB would have to be), and 2) there are no obvious values which makes an island maximally great. It is relative to the person. What makes an island great for one person may not make the island great for another. Further, an island could never reach maximal greatness. There could always be one more palm tree.

In order to create a successful parody, the opponent of the argument must deposit a being which is 1) defined as necessary, and 2) able to reach maximal values (whatever those even are). These reasons are why every parody of the argument breaks down; once a person deposits a being that meets these two criteria, the being deposited starts to look a lot like the Maximally Great Being the opponent of the argument is trying to avoid in the first place.

Another common attempt to disqualify the argument is to say the argument begs the question. Philosophically, to beg the question is to assume the truth of the conclusion in a premise of the argument. In other words, you use the conclusion in a premise to argue the conclusion. Some contend that the ontological argument begs the question in the first premise where it states that it is possible that God exists. Objectors say this first premise is equivalent to the conclusion. Does this objection render the argument fallacious?

Not really. There exists a difference between statements being logical equivalent and being synonymous. The ontological argument sets up the first premise to be logically equivalent to the conclusion, and it relies upon the following premises to draw out the conclusion. This just makes it a valid deductive argument. In a deductive argument, the conclusion is usually hidden in the premises, and it requires additional premises to bring about the conclusion. No one reading the first premise, “It is possible a Maximally Great Being (MGB) exists,” would automatically assume this statement is synonymous with the statement, “A MGB exists.” The point of the argument is to bring the reader to the conclusion that if a person is committed to the possibility of God’s existence, it follows they must be committed to the belief in God or else hold logically contradictory views, and per the ontological argument, to postulate the possibility of the existence of God is to say God (or a Maximally Great Being) actually exists.

“For His invisible attributes, that is, His eternal power and divine nature, have been clearly seen since the creation of the world, being understood through what He has made” (Romans 1:20).

16 thoughts on “Alvin Plantinga’s Ontological Argument

  1. Pingback: Why Christian Unitarianism Fails – The Resident Theologian

    1. Sorry for taking a while to respond; I’m just now seeing your comment.

      I think I see what you mean. In short, the argument (in regards to the first premise) is not intended to promote mere speculation as to whether or not a MGB exists; rather, the goal is to say that the mere metaphysical possibility of a MGB inevitably leads to the necessity of a MGB (via the rest of the premises of the argument).

      Therefore, when I say that it is possible a MGB exists, I’m not simply trying to give benefit of the doubt in favor of a MGB existing (we still have to go through the rest of the premises in order for the argument to be effective). Instead, I am recognizing that there is nothing which makes a MGB an impossibility (the key claim which many atheists dispute). That’s really the point of the first premise.

      Ultimately, the argument in sum is meant to determine what category a MGB would go under (necessity, contingency, or impossibility).


      1. David W Schell

        Oh, no worries:) I appreciate your time and response.

        So with regard to this argument and given the nature of infinity (The fact that there are infinite factors to account for which is logically impossible for us to reasonably consider), isn’t it fair to say that the argument shouldn’t be used for persuasive purposes since its goal is not to invite or “promote” philosophical speculation of an MGB?

        Additionally, let us assume that an MGB does exist. Does it logically follow that said being created the universe? Couldn’t the universe be infinite (in the sense of self-existent matter and energy (i.e. mereological nihilism)) in addition to an MGB (this relates to the metaphysical component (i.e. God is not metaphysically responsible if the universe is infinite [this kinda undermines the idea of God being metaphysically necessary if that makes sense]))?

        I suppose a counter from your standpoint could be the following: “If God didn’t create the universe, then the universe would be something of which God didn’t create thus making him not an MGB which is logically contradictory and thus not possible when referring to an MGB (This ultimately helps the defender of this argument in case my sentence was unclear).” However, I think I could counter this by stating the following: (1) “If God can’t create an infinite universe, then God is not omnipotent”. The follow-up from the first part would be: “God couldn’t create an infinite universe because it wouldn’t have had a beginning thus making this notion logically absurd”.
        (Honestly, I can’t think of a retort to this point given you agree that God can’t create an infinite universe. I’m curious as to your thoughts on that).

        Forgive me if I’ve overlooked a crucial point or forgotten something from your article. I did read it a while ago.

        Honestly, the only other problem I have with this argument is the problem of evil and suffering under a compatibilist Christian paradigm in which hell is eternal. It seems like it would be better for God to not create humans with free will in the first place than to create a world in which some go to hell. I’m at the point where I logically have to concede the pointlessness of our existence unless we have free will. Additionally, under this paradigm, I have equated “good” to societal well-being which is seemingly dichotomous with people going to hell. This seems to show that an MGB doesn’t exist under such a model. Lastly, this definition of good is derived from biblical standards.

        A formal argument for this is here:

        P1: If God is all good (moral), then he must do what is best for the well-being of all.
        P2: Some people go to hell.
        P3: If some people go to hell, then God has not done what is best for the well-being of all.
        P4: If God has not done what is best for the well-being of all, then God is not moral.
        P5: If God is not moral, then God is not maximally great.
        P6: If God is not maximally great, then He is not possible.
        Conclusion: God (MGB) does not exist.

        These are my main objections regarding the ontological argument. If you get to this, I’ll be impressed lol. If you want, you can answer them one by one when you feel like it. This way, you won’t be pressured to answer it all in one massive block of text lol.

        Thanks for responding and happy Thanksgiving if you don’t see this for a while.


      2. I appreciate your patience! With the end of the semester, I have found myself writing and working a good bit.

        There’s a lot to digest here, so I’ll just go paragraph by paragraph.

        When I said the argument is not meant to promote speculation, what I meant is simply that the intent of the argument is not to appeal to ignorance and loosely offer the mere possibility of God’s existence as if to say, “Well, we might as well accept a MGB’s existence if it’s possible one exists.” I use speculation in its negative connotation there. The argument as laid out can still be persuasive if the logic is valid and the premises substantiated, and one can determine if the premises are substantiated without reasoning through every last possible world. But I don’t think there are an actually infinite number of possible worlds. If nothing else, its just a really big number of them.

        I would agree that it does not immediately follow from there being a MGB that this MGB created the universe; however, one could work backwards from that there is a universe to a Creator as first cause arguments do, and I have written on that subject elsewhere on my blog (and the properties of that Creator as a result). There are a few problems for an infinite universe. For most physicists, the problems have to do with the universe expanding as it could not do so from infinity (objects can only be so small before they cease to exist as they cannot sustain themselves).

        In regards to your questions on an infinite universe, even if the universe is infinite, this does not explain why the universe is. In other words, what sustains the infinite existence of the universe? Why something rather than nothing? This is Leibniz’s argument from the contingency of the universe, and I have written on that argument as well. Metaphysically speaking, an infinite universe would derive from God from infinity. The problem would be whether an actually infinite universe is possible as the concept of an actually infinite quantity of something is logically impossible (as I think and other philosophers like William Lane Craig have defended). God of course would in this case be eternal (not quantifiable by time), not infinite (which would be quantifiable). This is not a problem for the ontological argument (OA) if a MGB does not have a property or cannot perform an action which is logically impossible. Of course, neither of these points influence whether the OA is sound.

        Concerning your questions about the doctrine of hell, one could argue that freedom of the will is a good which overrides the horrors of hell. I think this understanding is implicit in your statement that existence is meaningless without free will. In having the ability to be responsible moral agents who act in accordance with the risen Christ, we are able to reign well with Him not as a result of a series of mechanistic causes but as the result of our volitions genuinely yielding to Him (1 Cor 6:3, Eph 3:17-19). Our bona fide acceptance of God’s favor in Christ does not undermine our love for Him as it would if we were simply determined to be that way. C.S. Lewis made this point that hell does not get veto power over heaven; in other words, just because there are persons who end up in hell does not mean God has wronged them especially if on the Christian view the denizens of hell are there of their own accord. Further, my problem with your formal argument would be the first premise where it assumes that it is most moral to do good for all even those who by their own fault live outside of communion with God. Rather, I believe a more biblical understanding of goodness is the glory of God in whom and for whom all things exist (Col 1:15-20), and, according to classical conceptions of theism, is the Good.

        In sum though, I do not believe the objections you have raised here are defeaters of the OA even if they hold true. The objections you have raised would be more about identifying the MGB of the OA with the God of the Bible rather than about the inherent integrity of the OA itself.

        I hope your Thanksgiving was good and the same for this holiday season!


  2. Dave

    For the first point, I was referring to God and his properties (which by definition have to be infinite. (This is especially true regarding omniscience considering the topic of epistemic possibility.)

    As for your second point, I’m currently looking into this subject more and I find it generally convincing. I personally find the idea of an infinite regress of events illogical as one runs into paradoxes. The key distinction between God and the universe would be an infinite regress of “states” versus an infinite regress of “events”. In other words, God could maintain a state of oneness and then, given his libertarian free will, choose to create, whereas an infinite state of nothing could not (given the lack of libertarian free will to alter its current state). I do believe somewhere, that I heard the idea of a causal loop being proposed regarding the first cause. However, I don’t personally know enough at the moment to feasibly consider that idea. The typical objection effectively states that the created thing doesn’t really have an initial cause. However, I don’t know if this is illogical in regard to the universe.

    Thirdly, I’ve considered the free-will theodicy. My only reasonable objection would be the following: “If being with God eternally is the greatest good ever, then being apart from him is effectively the antithesis of that. However, I think that one could posit a retort such as the following: “Should marriage (permanent relationships) be prohibited due to the actuality that some people will be forever alone?”. I would personally say no. Additionally, I think that’s the best analogy for this topic (it’s also presented in the Bible) although it’s not nearly as extreme. It’s intellectually dishonest to ramp up one without the other.

    3.1 Compatibilism: I think as soon as you posit a logical universe, you reason determinism or compatibilism for humans. With this said, I don’t think compatibilism forfeits the reality of loving bona fide relationships. All it means is that the being is determined to choose given the parameters exhibited in the metaphysical equation of life. Effectively, this is why one could argue that certain people are condemned from the getgo. They just got the short end of the stick. With this said, it does seem like God wronged them. The best retort, in my opinion, is a sort of “necessary evil to achieve good” theodicy.
    3.2 Plato’s Euthyphro: Personally, I think the pious is pious if he has pie but hey that’s just me XD.
    Seriously though, I would argue that God is the literal embodiment of goodness. However, good is a description. Given the promotion of certain ideas in the Bible, I think it is perfectly fair to conclude that good acts have to do with well-being. If not, then one runs into the problem that C.S. Lewis presents.

    “If God’s moral judgment differs from ours so that our ‘black’ may be His ‘white’, we can mean nothing by calling Him good; for to say ‘God is good’, while asserting that His goodness is wholly other than ours, is really only to say ‘God is we know not what’. And an utterly unknown quality in God cannot give us moral grounds for loving or obeying Him. If He is not (in our sense) ‘good’ we shall obey, if at all, only through fear — and should be equally ready to obey an omnipotent Fiend. The doctrine of Total Depravity — when the consequence is drawn that, since we are totally depraved, our idea of God is worth simply nothing — may thus turn Christianity into a form of devil-worship.”

    Although I think this is only partially true (due to the issue of moral relativism), I think we have grounds to assert that we bear the image of God. If we cannot conclude well-being is the standard of good, then we cannot reasonably differentiate Christianity from Islam.

    Lastly, your final assertion is correct. Frankly, I love Plantinga’s Ontological argument. It lays out a conceptual playground in which one can accurately decide whether they believe in God or not. However, in order to conclude Christianity, one needs to align God with the OA’s definition.

    Additionally, I think the reverse ontological argument (ROA) makes the OA alone useless in the sense of inferring God’s existence. When (the ROA) is posited, other arguments must be drawn on (e.g. the cosmological argument) to affirm the OA’s conclusion. With this said, I still think the argument has tremendous value in conceptualizing such conclusions.

    I had a wonderful holiday. Thanks for asking and replying!


    1. Ah, then I’m confused by what you mean in your first point then. What are you saying there? I will say however that I don’t think God’s properties have to be technically infinite, only maximal. Typically philosophers of religion and theologians define omniscience as when a person S knows/believes every true proposition and believes no false proposition. In other words, God knows everything there is to know. This is not the same as an actual infinite (as there are not an actually infinite number of things to know), but it is more akin to a potential infinite even. The same applies to omnipotence and omnipresence.

      To the second point, I agree with you concerning the problems of an infinite series of events or even states. Typically theologians wouldn’t apply an infinite series of anything to God insofar as it might indicate that God is subject to time (and especially considering Einstein’s contention that time is not infinite). The eternal-infinite distinction would again be crucial here. But yes, God’s freedom (insofar as He is not determined by external or even internal causes) is crucial as it would allow Him to create in ways an impersonal state of necessary and sufficient conditions could not. The causal loop I think are fluctuation models of the universe where the universe is in a series of expansions and contractions. At least that’s one way of conceptualizing it. Of course, that would just be another infinite series but with extra steps, so it doesn’t really solve anything. Inevitably the buck must stop somewhere if we dispense with the idea of an infinite regress.

      To the third point, I don’t think I’m grasping the objection to the free-will theodicy. Are you saying that God ought to work towards the greatest good for all persons? If so I’d be curious as to where that obligation would originate from. I do like the marriage analogy though as it is biblical and is offered as a parallel for what communion with God is like.

      3.1, In what way does positing a logical universe lead to either compatibilism or determinism? Are you referring to the problem of logical fatalism? Or a universe based on mechanistic laws? I agree that compatibilism is ultimately unsatisfactory to account for genuine moral responsibility (I take up that argument in another one of my blog posts). Liberation freedom (defined as liberation from causal determining factors) in both motivations and actions are needed for a fully formed account of moral responsibility.

      3.2, Lol, nice.

      I agree that goodness has to do with well-being, but that well-being should be defined in terms of its ultimate purpose or aim which the Bible lays out as life in communion with the triune God (1 Cor 15:28), and this provides adequate grounds for distinguishing Christianity from other moralities and religions especially if one inquires into the nature of love: it must be between persons which (as I have argued on the blog) leads to a multi-personal God.

      Finally, I would say the OA posits the connection between God’s possibility and His necessity; namely, the former entails the latter. But I don’t think the ROA (at least the formulations I have seen) are persuasive for the reasons I give in the article above. The argument breaks down in the subsequent premises after premise 1.

      Good to hear. Again, thank you for your patience. Grad school is a cruel mistress.


      1. Dave

        1. My initial comment was “Hey quick question, is or isn’t this argument just an appeal to ignorance? I mean this in relation to the first premise.” What I meant was the following: It seems like it would be better to remain agnostic on the proposition of God (MGB) since there is an infinite amount of logical considerations to account for regarding omniscience. There could or could not be logical contradictions within the title “omniscience”, Given the infinite possible details of this claim, it would be logically impossible to reasonably consider all its aspects. I could agree with you on things like omnipotence. With omniscience, however, an MGB should be able to consider/know all impossible propositions (of which there are an infinite amount). I hope that makes sense. I suppose I was a bit unclear in my previous assertions.
        1.1 Furthermore, to deviate from my presuppositions (by assuming the potential infinite of omniscience as opposed to the actual infinite) would imply that God is constantly learning and therefore not all-knowing. This is at least how I see it.

        2. Wow that was really helpful in expanding my conception. Thank you so much for that!
        2.1 Infinite loops: Briefly, I will mention that I have arrived at the conclusion that a contingent thing must be created. If the universe is contingent (which I think it is), then it could not be created given a time loop. A common example is the mathematical formula discovery in which its cause is determined by a future person giving it to a mathematician in the past who then gives it to the initial time traveler in the future ad infinitum.

        3. Free-will theodicy: I will expand as I am now realizing my initial spew of information was a bit unclear. I think a maximally good being ought to create the “most good” outcome. If God created a universe where all living things went to hell, then I don’t see how he could be maximally good or omnibenevolent. This is my origin for the claim. My objection stemmed from this presupposition.
        3.1 Compatibilism: If the universe is logical, there must be logical reasons why one thing happens and not the other. We use this form of reasoning in cosmological arguments (e.g. events, causes, etc…). Here’s a makeshift formal argument for it.

        P1: Our universe exists.
        P2: If our universe exists, then it must be logical.
        P3: If it is logical, then everything must have a reason why it is the case as opposed to not the case.
        P4: Our universe is logical:
        C1: Therefore there must be logical reasons why this universe is one way and not the other.
        P5: If there are governing logical rules that determine the result of this universe, then the results could have not logically been another way given the actualized parameters.
        C2: If our universe could not have been another way, then the universe must be determined.

        Our free will is part of the metaphysical equation regarding the logical happenings of the universe.

        I’ll check out your article on compatibilism. For the record, I think, as of now, that morality does work under a compatibilist account of things given the ultimate results (consequentialism). I know a lot of theists don’t like this line of reasoning but I think I can make work. Additionally, it seems logical. Ultimately, I’m looking for a consistent worldview.

        3.2 Exactly! We agree. Consequentialism. Btw, I’m completely down with the trinity on a conceptual basis. Biblically, I’d like to learn more about it, but conceptually and philosophically I’m fine. However, I think the ultimate good that takes place in heaven would have to deterministically result from the pre-occurring metaphysical factors. It seems like you would have to concede this as well, no?

        4. The ROA I’m referring to:

        1) It is possible a Maximally Great Being (MGB) doesn’t exist.

        2) If it is possible an MGB doesn’t exist, then it does not exist in some possible worlds.

        3) If an MGB doesn’t exist in some possible worlds, then an MGB doesn’t exist in every possible world.

        4) If an MGB doesn’t exist in every possible world, then an MGB doesn’t exist in the actual world.

        5) If an MGB doesn’t exist in the actual world then an MGB doesn’t exist.

        Now for discussion. Ok, I quickly re-read through your article as it has been a while since my initial viewing. Forgive me if I’m misrepresenting your views or the OA’s assertions. This is not my intent.

        Actual criticism: However, An MGB’s necessity must logically apply metaphysically. So, if an MGB does not exist in some possible worlds, then that means that there are logically possible worlds in which an MGB does not exist necessarily. Similarly, If an MGB exists in some possible worlds, then it logically follows that there are some possible worlds in which God (MGB) does not exist. If either possible world is logically coherent, then necessarily, we have arrived at a contradiction of the two positions, namely “God exists” and “God doesn’t exist”. To resolve this issue, we have to go to alternative arguments like the cosmological argument to see which of the two propositions is logically impossible. This is why the argument (OA) doesn’t work by itself and needs to rely on other arguments for sustaining its ultimate conclusion. Graham Oppy notes this when debating an OA enthusiast, Ben Arbor. Ben Arbors’ retort is to draw on other arguments for God’s existence. Ultimately we’ve made it nowhere regarding the goal of inferring God’s existence. All we’ve effectively done is say that he either does or does not exist necessarily. Make sense?

        As a final note, this is why I see the OA as merely a tool for testing the concept of God. Ultimately, it promulgates questions regarding the topic. Apart from this, it doesn’t really do anything to suggest a probable reason why God exists. Usually, most people are at this point anyway. They think the idea of God’s existence is impossible or true given their current knowledge.

        No worries about your time getting back to me. I completely understand. Good luck and thank you again for speaking with me.


      2. Now I must really thank you for your patience. I knew it would take me a while to adequately respond to everything here, so I am grateful.

        1. Okay, I think I’m tracking with you. Basically I think it’s faulty reasoning to say that because we cannot from our limited position survey the infinite (or potentially infinite) number of aspects regarding the content of God’s knowledge should He be omniscient (which is what I am garnering by you referring to the infinite amount of logical considerations regarding omniscience) that therefore we can say nothing about the category of omniscience in sum. In other words, we don’t have to navigate the particulars of what God believes in order to conclude that He does believe it (given the standard definition of omniscience provided above). I would clarify though that if there is an impossible proposition (by which I am assuming you mean a proposition containing a logical absurdity) then God would not believe it to be true since it cannot by its nature be true. Or else, God would know that such a proposition was in fact impossible or even nonsensical.

        1.1 Well, I say potentially infinite insofar as the truths God knows is not actually infinite (as I think such is impossible and would require an infinite state of events). It’s not that a proposition becomes true and then God simultaneously learns about it. It’s more that God has eternally comprehended these truths even as they have yet to be actualized (hence why God has foreknowledge). Again, the eternality of God in regards to time would be an important distinction here.

        2. Yes, of course!

        2.1 I agree with you, but it is possible that the universe could be contingent yet infinite. The only difference would be that some cause sustains the existence of the universe from infinity (again assuming an actual infinite is possible). But that gets into arguments for God as necessary from mere contingency rather than an absolute beginning.

        3. Ah, I see what you mean, and I tentatively agree. The only caveat I would have is that the denizens of hell could be there as retribution for their own volition, so in that sense God is not unjust. Perhaps from our perspective He would not be omnibenevolent in regards to us, but then again that assumes that God would owe us benevolence which I think is a hard hill to climb as it would need to substantiate moral duties for God towards us.

        3.1 I see what you are getting at with your argument. You might be surprised to hear that this is actually not too dissimilar from Aristotle’s argument for logical fatalism. That is to say, Aristotle grappled with the idea that if a proposition is true, then it must be always the case that it was true and thereby fated. He ultimately disagreed with this premise (for reasons about which people disagree), but his formulation of the argument was similar.

        I think I have three main qualms with this argument: a) I think “logical” needs to be better defined. Do you simply mean the physical laws of nature as they appear or the rules of logic (i.e. Law of Noncontradiction) which overlay all of reality? The answer will matter as the former is more or less an argument for causal determinism from the laws of nature (which I think thereby negates moral responsibility completely and thereby is not compatibilism), and the latter is like Aristotle’s argument as described above. b) I disagree with the implication behind P3 in that it presupposes that a “logical” explanation would only result in one particular outcome and not another when we know that isn’t always the case with acts of intentionality (i.e. actions originating from the mind) or even in quantum mechanics where many of the outcomes could appear one way or the other in regards to how the agent involved performs an act of measurement. c) This argument might actually beg the question in P3 in that it implicitly presupposes determinism which is what you are arguing for in the first place.

        It is also worth noting that for this to be an argument for compatibilism, an account must be given for moral responsibility since what needs to be made compatible is moral responsibility with a deterministic framework. I am also not sure what you mean by free will being part of the metaphysical equation regarding the logical happenings of the universe? Do you mean that the concept of free will is subject to logical laws (i.e. Law of Noncontradiction)? If so, I would agree with that, but with the caveat that logical fatalism does not necessarily follow from that.

        Yeah, let me know what you think about the compatibilism article. If you need it, I can give the link. There I am engaging both with Galen Strawson’s argument for causal determinism and Louis Pojman’s compatibilist response from a libertarian perspective and why I think that option is to be preferred.

        “Ultimately, I’m looking for a consistent worldview.” Dude, same, haha.

        3.2 It’s not really consequentialism insofar as the consequences are not the primary motivating factor in decision making. Other goods are considered from the outset such as truth, virtue, community, and beauty (among other things). On consequentialism these goods would be put aside for a simple examination of the consequences of an action or set of actions. I would say a biblical paradigm is closer to Aristotelianism, but biblical morality is ultimately its own system although it resembles aspects of other moral systems (i.e. virtue ethics, deontology, etc.)

        4. Ah, yes, this is the argument I was thinking about. Basically where this argument breaks down is P3 where it says that if an MGB doesn’t exist in some possible worlds, then an MGB doesn’t exist in every possible world. Reason being that if an MGB did not exist in some possible worlds, then it would therefore be contingent; however, if one wished to say then that the MGB does not exist in every possible world, then the MGB must be impossible. In order to determine that, there must be something about the MGB which is impossible (i.e. a contradiction in the concept of an MGB, etc.). In other words, the movement is not clean between some possible worlds to every possible world given if one starts with a contingent MGB which exists in some possible worlds but not others. This is ultimately why the real premise under dispute in the original OA is the first premise which is attempting to sort out whether or not an MGB is possible at all. We don’t really end up with the two contradicting propositions (God exists and God doesn’t exist) because the OA moves from the MGB being existing in some possible worlds to existing in every possible world by the nature of what it means to be an MGB. The MGB by definition would be necessary for if it was not necessary it would not be an MGB, so there not much of a point where God could exist in some possible worlds but not others if He truly fit the description of a MGB.

        I do agree that the OA is a good place to test the idea of God, but it ultimately goes much further than that. It really gets to the heart of what the theist is arguing for.

        Again, thank you for your patience! I finally found time to respond as I have been a bit burnt out on actual school work and can refresh myself on this discussion. It’s actually quite nice.


      3. Yeah, of course. Crazy past couple of months.

        1. I was using the term “believe” to loosely be synonymous with “know.” The implication is that if God believes something then He knows it given the standard definition of omniscience where if a certain proposition (P) is true then God believes that proposition and disbelieves any false ones. I’d be curious as to what kind of distinction could be made between the two terms as God’s beliefs by definition would constitute a form of knowledge. I think the above definition clarifies sufficiently what scholars mean when describing omniscience.

        A human couldn’t be a MGB because a bone fide MGB would be necessary and exist in every possible world which of course a human could not fulfill as we are contingent by nature. I don’t see why God wouldn’t be omniscient given the above definition. I doubt that the number of true propositions are actually infinite, but I don’t see any hangup with stating that God is omniscient if the above definition is coherent.

        1.1 I suppose in this case I would just repeat my objection about the logical absurdities behind an actually infinite number of anything (including propositions). The Hilbert’s Hotel thought experiment I think demonstrates the problem quite well (i.e. actual infinities produce logical absurdities).

        2. Cool, I’m glad we can find agreement here. I would just take that agreement and apply it to the above.

        3. Yes, I agree here as well that compatibilism is ultimately insufficient to provide a genuine account of moral responsibility.

        Here I would partially agree with you. I would certainly say that God acts in the good because He is good. However, I would strongly contest the notion that hell is not an act of goodness. We don’t largely perceive hell in this light because it is an act against us (i.e. retribution for wrongdoing); however, just because we don’t end in a state of contentment does not mean that we have been treated unfairly. God’s actions towards us in seeking our redemption in Christ I would say is a supreme act of goodness because it is an action seeking our reconciliation with Himself and with one another. Our rejection of this kindness does not negate His goodness in this sense. I would again state that the language of “owing” is problematic because it presupposes implicitly that God is somehow in our debt which is a claim that needs substantiation.

        3.1 Haha, yes, that topic is a can of worms; however, I will contribute to that subject in that free will does not treat these outside environmental influences as irrelevant. If anything they are merely that: influences, and we are not necessarily at their beck and call.

        I would strongly disagree with that definition. I think a more tenable definition is “the self-determination of an agent to act in ways not caused or determined by external forces.” In this way, free will is more defined by what it is not. Namely, it is actions originating not from deterministic causes. Put another way, on determinism you could hypothetically trace a series of causes in order to see how an agent will behave every time. On libertarianism, one could not do this with any degree of certainty.

        Sweet, more agreement, haha.

        4. Of course! To your question, I want to word this carefully so that it does not seem like I’m having my cake and eating it too. The important distinction between the OA and the ROA is how one defines a MGB coming into the argument. A MGB is by definition necessarily or else a MGB would not be a MGB. Where this is relevant is that in P3 of the OA, the truth of that premise follows by the nature of necessity. It’s important to note what the OA is doing here in being a deductive argument. It is taking P1 and unpacking what the implications of P1 are via deductive reasoning. The point of the argument is showing how it is the case that really P1 and the conclusion are actually stating the same thing but in different terms. In one sense that just makes it a good deductive argument as that is what deductive arguments try to do and ultimately why P3 of the ROA does not work. Given the definition of a MGB being necessary, the ROA would have to show how P1 and the conclusion of its argument are logically equivalent, but the steps it takes (i.e. the following premises including P3) to get there are faulty. P3 of the ROA is faulty because it contradicts what it means for a MGB to be what it is. If a MGB is necessary by definition, then premise 3 negates this definition and has actually denied a MGB being what it is. Really the whole of the ROA is an attempt to deny the nature of an MGB and is perhaps in this sense question begging. I hope this makes sense as it is a bit more of a technical point and I may not have stated the issue as clearly as possible.

        I appreciate your commitment to discerning what is true, and I am grateful for what role I’ve been able to play in that process. I wish you grace and peace as you continue to unpack these significant questions.


  3. If premise 1) states that the MGB exists in a Possible World that is not the Actual World, that existence must be Hypothetical/Imagined Existence. I say this because all Possible Worlds that are not the Actual World are hypothetical/imagined rather than actual.

    If so, does it not follow that conclusion 5) must be that the hypothetical/imagined MGB also exists in the Actual World?

    Do we have a case of conflating Hypothetical/Imagined Existence with Actual Existence?


    1. Not necessarily as describing possible worlds in this way is a misunderstanding of how they are employed in modal logic (propositions concerning possibility and necessity). Possible world semantics is largely a linguistic tool which is used to discern whether something is necessary, contingent, or impossible. They are not as such merely hypothetical/imagined worlds in the way you are using them.

      To quote Stanford’s Encyclopedia of Philosophy on this point, “Although ‘possible world’ has been part of the philosophical lexicon at least since Leibniz, the notion became firmly entrenched in contemporary philosophy with the development of possible world semantics for the languages of propositional and first-order modal logic … these languages contain operators intended to represent the modal adverbs ‘necessarily’ (‘□’) and ‘possibly’ (‘◇’).” I recommend checking out the full article (“Possible Worlds”) as it is really helpful on this point.

      The point of the ontological argument then is to establish a MGB as possible (thereby occupying at least some possible worlds) and then therefore as necessary given the nature of a MGB. Which is why ultimately the real controversial premise is premise 1) and not really any of the others which follow from premise 1).

      I hope this helps!


      1. Dave

        For the record, I am just happy someone is interested enough to converse with me regarding this stuff. Thank you.

        1. If you could change the word “believe” to “know” I’d feel represented properly. I get what you’re saying though. However, I am not saying “that therefore we can say nothing about the category of omniscience in sum”. I am saying we cannot reasonably place trust or assurance in said notion solely on our own reasoning and understanding as it is flawed, biased, susceptible to ignorance and could be impacted by later information. To clarify, I think that we know too little of what omniscience would look or be like.

        Additionally, it seems that you have gone the general and malleable route of positing the most logical maximally great being. The thing with this is that, technically and for all we know, a human could be the only logically possible MGB. This would not necessarily entail metaphysical necessity. In summary, the point I’m trying to make with the stated information is the following: If God’s epistemic prowess is not truly encompassing of all knowable things (which I think are infinite (e.g. every number)), then he is not omniscient. He would just be really smart. I hope we are on the same page with this. I may not have articulated it as well as I would have liked. Please understand that this point is entirely devoted to the distinction between omniscience and extreme intelligence. If you go the route of defining omniscience as “knowledge of all knowable things consistent with each other” then I don’t think that truly is omniscience.

        1.1 I would agree with the notion that God has always known everything. I would probably disagree with the potential infinities regarding knowledge.

        2. (2.1). Yeah, I think I have issues with metaphysical actual infinities. But yes, you’re right.

        3. In regard to the denizens of hell, I see that as unfair under a compatibilist paradigm (Which you disagree with).

        Instead of saying God owes us benevolence, I suppose I think God owes good acts for the sake of being good. Can you really be maximally good if you knowingly don’t commit altruism (specifically regarding the big picture)? I don’t think so.

        3.1 Due to lengthy periods separating our response times, my views are evolving. I would disagree with determinism based on quantum mechanic experiments that suggest probabilistic outcomes as opposed to deterministic outcomes. However, I would still agree that our will is influenced by things outside of our control (e.g. our sex, culture, environmental factors, etc…). As a result, I’ll still use the term “compatibilism” to reference “free will” considering I’m not aware of alternative terminology. Just know I don’t necessarily believe in determinism anymore. The only case I could see for it is under some view of soft panentheistic Christian Idealism. However, that’s a topic for another day lol.

        My “compatibilist” definition: I would define free will as “doing what you want to do”. Under this definition, we surely do have free will considering we always do what we want. However, it also means our decisions are certainly influenced by outside factors. Like I said above, our gender, culture, and environment all have an impact on our spirit, mind, or whatever you want to call it. Mainly our decisions are influenced. Thus I don’t really see how anybody could have libertarian free will except for God.

        “I am also not sure what you mean by free will being part of the metaphysical equation regarding the logical happenings of the universe? Do you mean that the concept of free will is subject to logical laws (i.e. Law of Noncontradiction)? If so, I would agree with that, but with the caveat that logical fatalism does not necessarily follow from that”. I agree with this now.

        My apologies if my responses do not account for your article, I’ve been quite busy lately and I’ll try to check it out when I have time.

        4. Hmm, I’ve learned something new. Thank you! Let push back a little just in case I’m too eager. Could you not apply the same reasoning to premise 3 of the normal OA? Doesn’t positing possibility entail contingency?

        I’m glad this conversation provides you with some peace. I’m a wannabe philosopher who finds this stuff fascinating. You’ve provided valuable insights into my worldview throughout this discussion and I appreciate the time.


      2. Hi RT, thanks for your comments. I do have another comment that relates to how P1 is sourced. I see the Modal Logic Ontological Argument as part2 of the whole argument. What I show below is the missing part1.

        a. All Possible Worlds are derived from the Actual World.
        b. The Actual World and all Possible Worlds share the exact same Necessary Being.
        c. The Necessary Being of the Actual World [aka the Actual Necessary Being] has at least the capabilities required to cause every instance of causation that is attributed to it.
        d. The Actual Necessary Being is at most the Maximally Great Being.
        e. If it is proposed that the Maximally Great Being exists in a Possible World, there must be a prior assumption that the Maximally Great Being exists in the Actual World. [from a. and b.]

        You may say that I am ignoring what you just said to me – I am attempting to relate this to actuality rather than to an esoteric philosophical construct. If the underlying purpose of the OA is to “prove” something about the Actual World, then I suggest that my comments have relevance, whereas if the whole purpose of this OA is to be no more than an exercise in Modal Logic with no application to actuality, then I concede. But if the latter, then nobody should use it in any attempt to argue about actuality – and that includes that it should not be used in the context of the existence or otherwise of God. rgds, Ian.


      3. Hey Ian, thanks for the contribution.

        I would argue that a. is untrue. Even though I am not certain what you mean by this premise, if I am discerning that what you mean is that all possible worlds are constructs of the actual world (let me know if this is a misrepresentation) which I think is plainly false as it unnecessarily collapses the two concepts of a possible world and an actual world without proper warrant. Further, there may be some equivocation between the terms “actuality” and “actual world” as has been used above. For example, it may in actuality be the case that the proposition “unicorns exist” is true in some possible worlds even though it is not true in the actual world.

        The point of the OA is to demonstrate the equivalence between the P1 and the conclusion. In other words, it is meant to show how the possibility of MGB entails the necessity of a MGB and how therefore a MGB exists in the actual world as our actual world is merely one of many possible worlds.

        Further, I don’t think your argument structurally is a valid logical argument as the conclusion does not neatly follow from the preceding premises. I suggest tightening the language so as to avoid confusion (like the difference between “actuality” and “actual world”) and to show how it must be certain how one premise follows another. The OA above uses modus ponens to construct its argument which is helpful for showing the relationship between the succeeding premises.

        Hopefully this clears up what the OA is doing.


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