ah the ontological argument where philosophers of religion try to define God into existence this video is going to be about the modern modal ontological argument put forward by apologists like Alvin PLA and defended by William Lane Craig now we're going with this version of the argument because the original ontological argument put forward by St anlam and philosophers like Renee dekart was refuted decisively by philosophers David Hume and Emanuel Kant since the original ontological argument assume that existence was a property of a thing you can go Google that but pretty much all modern apologists won't even attempt to defend that original version of the argument so let's go through the modern modal modal ontological argument put forward by plantinga premise one a being has maximal excellence in a given possible World W if and only if it is omnipotent omniscient and wholly good in W and premise two a being has maximal great if it has maximal excellence in every possible World premise three it is possible that there is a being that has maximal greatness premise four therefore possibly it is necessarily true that an omniscient omnipotent and perfectly good being exists premise 5 therefore by axm S5 it is necessarily true that an omniscient omnipotent and perfectly good being exists and the conclusion therefore an omniscient omnipotent and perfectly good being exists now before I continue I want to acknowledge that the first part of my criticisms and a number of my examples here are taken largely from The Atheist blogger Chris halquist he writes an excellent blog called the uncredible Hal and I highly recommend checking it out one of the things he points out is that this argument is so annoying is that is because it's so easy to see that it's wrong but it's so hard to point out exactly what is wrong with it and Chris was the first person I read online who highlighted exactly what was wrong with the argument technically and why so I'm going to include a link to his reputation in the description box and again I highly recommend checking out his blog it's fantastic so the modal argument hinges on Axiom S5 which is a system of formal logic basically if you're going to do formal logic you can pick which system to work under and so long as you stay consistent with that system and obey the axioms everything's fine fine now for the record there aren't really any problems with the S5 axioms of modal logic this is basically the logic of possibility and necessity you pretty much just have to be aware of what you're dealing with before you start drawing conclusions from an argument made in this system so the problem here is that once you start operating under the S5 system making certain assumptions and just running with it is pretty much absurd the argument relies on granting what sounds like a reasonable assumption that X is metaphysically necessary and also X possibly exists the issue here is that under the S5 system this is literally logically equivalent to saying X exists necessarily now this is problematic because when we're having a normal argument that's kind of informal we can say yes sure for all we know it is possible X exists where X can be anything from leprechauns to unicorns to fairies or Gods now the problem is that when you're in the S5 formal system if you say something that is defined as necessary possibly exists you may as well start with a very silly argument premise one God is defined as an omniscient omnipotent holy good being that is something that exists in any possible World premise two an actual World exists the conclusion therefore God must exist this is a logically valid argument but it tells us nothing this is this is why Alvin pla the guy who came up with the modal version of the argument admits that while the argument is logically valid it doesn't prove anything to quote our verdict on these reformulated versions of St anam's argument must be as follows they cannot perhaps be said to prove or establish their conclusion but since it is rational to accept their Central premise they do not they do show that it is rational to accept that conclusion now that last bit about the argument showing that it's rational to accept the conclusion is still way off the mark but I'm going to come back to that later what I want to highlight here is the difference in honesty between Alvin PLA and William Lane Craig at least planninga acknowledges this major issue with the argument and admits it Craig on the other hand just presents the argument in debates and acts as if it were somehow a valid proof of a god existing necessarily in all metaphysically possible worlds it just shows the difference between someone doing actual philosophy of religion and someone trying to use arguments to evangelize people now here's a great example that I got from Chris halquist to show why granting the possibility of something that is metaphysically necessary under S5 motolog logic is patently absurd most philosophers hold that mathematical truths are metaphysically necessary truths now there's something called goldbox conjecture in mathematics which is an unsolved problem in number Theory the conjecture States every even integer greater than two can be expressed as the sum of two primes now if you think about it this appears to be true and it's actually been shown to hold through 4 * 10 the 18th power but it's never been proven however if it were true then it would be a metaphysically necessary mathematical rule because of this we could use a m ontological argument to show that it must be true now I'm not going to read through all the premises you can take a look at it here but what you can see from this is that it turns any unproven area of mathematics that might be true into something that must be true this is frankly absurd even mathematical theories must be proven to be true not assumed to be true until proven false so even on pla's much more modest claim of the ontological argument making belief in a god rational or reasonable the argument doesn't actually add any extra justification to the original premise you might as well say that the idea that God exists is inherent isn't inherently contradictory so therefore it's rational to believe it when you restate the argument in the on this modal ontological form you're not actually saying anything new you're just dressing it up in formal logic and making it sound good now if we just left it at that we'd technically be correct but it's not exactly satisfying and apologists would probably push on this maybe they would even be willing to bite the bullet on mathematical problems and say okay if you come up with a non-contradictory mathematical Theory we'll just assume it's true until Prov invalid because the payoff for the ontological argument is so big so for these folks I have a much more fun response to the ontological argument welcome to the great demon objection note I am specifically using a great demon as my example for a few reasons first if we were to use the classic objection of a maximally great island or the straw man maximally great lion William L Craig likes to throw up then apologists can say that material things like that can't really be metaphysically necessary since we know that outside of our SpaceTime they couldn't really exist I also specifically call it a great demon since if we called it the evil God then apologists can throw up a semantic smoke screen and say that a God by definition is something that is worthy of being woried so for these reasons we call it the great demon objection now I'm going to present the syllogism here it's literally exactly the syllogism that we had at the beginning except we just replaced uh perfectly good with holy evil and yeah you can check it out I hope you could agree that this is a pretty strong reductio ad absurdum defeater for the modal ontological argument but there are a few weak objections apologists can throw at this greater demon and I want to kind of refute them before moving on now the first objection is that it claims that a maximally evil being is impossible since only the good exists and evil is to be defined as the absence of good but this is obviously wrong for two reasons first is that it gets rid of the idea of morally neutral actions which we know exist from our experience but more importantly it fails because it's nothing more than a BAL assertion we could just as easily say that only evil exists and good is the absence of evil and we'd have just as much justification for stating things like that now the second objection that you can get thrown at you is that an omnicient being would have the knowledge of an absolute moral law and as such it would be incapable of evil since it would feel convicted by the moral law and pretty much the this would kind of go on and say that all beings aren't really evil they just kind of rationalize evil actions so when they're doing something evil they actually believe it's the right thing to do and people always want to do the right thing this objection is defeated fairly easily since we can say that evil is grounded in the Eternal nature of the great demon so it isn't convicted by an absolute moral law if a moral law like that existed in fact it would be driven to violate the moral law we could go a bit further and say that the perfect selfishness of the great demon means that it would be compelled not to do what is right but rather to do what brings itself pleasure which according to its nature is evil and violating the moral law finally we can reject the notion that people always do what they think is right since we've seen plenty of examples in the real world of people doing things they know to be wrong and going through with it anyway now if all that wasn't enough there's one final point I can make and it's that if the modal ontological argument is sound then we' have shown that at least two omniscient omnipotent beings exist but in this case it would be as if neither existed let's start with the idea that a maximally good being would make sure that ultimately only good things would result in any actual world so kind of like the Christian Theology of heaven and ultimately all of evil is defeated and put in hell but let's say the opposite is true for the great demon that they would ultimately make sure only evil would win in the end so if both a maximally good and a maximally evil being exist necessarily then they would cancel each other out this is because they would both be omniscient and omnipotent each knowing the other's uh thoughts and all possible outcomes of any action the other would take because of this they would use their omnipotence to stop any action that the other being tried to enact as a result if both beings existed necessarily then the actual world would be as if neither existed since neither one could act in the actual world now of course one way out of this problem is for an apologist to insist that only one omn omnipotent omnicient being could possibly exist but if that's the case then the modal ontological argument can't be sound since it equally demonstrates that two very different kinds of omnipotent omniscient beings could exist with no way to identify which one it is so by objecting they're defeating the argument they're trying to defend in the first place so that's going to conclude my counter to the ontological argument I hope viewers find this useful in being able to show exactly why the modal ontological argument is wrong and hopefully be able to provide some entertaining rebuttals to apologists who stubbornly def you know try to defend this laughably bad argument thanks for watching