G.K. Chesterton, in Orthodoxy, talked about the problem with crazy people. Talk to someone who believes crazy things -- say, a conspiracy theorist or a cultist -- and you will find that they are not, as you might suppose, without reason. They have a reason for everything. Indeed, they have too much reason -- an answer for every question, an explanation for every objection, a reason for everything from why their legs hurt to why the stars twinkle. The government did it.
It's easy to make up stories to explain experience. And they can be ruthlessly consistent stories. But the problem is that many of them are clearly wrong. One of the hallmarks of a crazy worldview is that it's flat and simple, playing the same notes over and over again, going back to the same explanations for everything. The person who believes the government is out to get him will use that as an explanation for everything, so his world is really quite shallow and sorry, telling only one sad little story.
Reality is not like that. It is complex and grand.
G. K. Chesterton talked about how to avoid this fate, and how to help people suffering it. The answer isn't to reason with them in their dark little rooms in a corner of reality. That does no good; they just run around their little well-trodden circuits. The answer is to go outside, get some fresh air, experience some of grandeur and complexity of the broader world.
I have actually had this experience myself. I was raised a young earth creationist, and from an early age was taught that anyone who believed in evolution must be very stupid, as it was so transparently rediculous and there were so many absurdities to it. I never questioned the proposition -- in retrospect quite silly -- that so many people beleived something so obviously false.
When I was in college, I took it upon myself to study the topic at a college level. I studied young earth creationists and old earth creationists and intelligent design and theistic evolution and naturalistic evolution. I learned about paleontology and biology and geology and astrophysics and philosophy and who knows what else. My husband was pursuing a degree in mathematical biology, studying mechanisms for spontaneous speciation, so I had some help from him.
And while it didn't take long for me to discard my young earth background -- a week or so, as I remember -- I expected that with a little bit of further study I could find the correct view. How hard could it be for an evidential person willing to commit a couple of years to the problem?
But I found that the more I studied it, the deeper the rabbit hole went. There is some weird stuff in origins. I mean really weird. The ancient landscape is alien, the history is remote. Folks from several sides made arguments I found persuasive, and after about three years of study, I came to the conclusion that nobody had the whole story. I resolved to consider it an open problem.
The journey from my very simplistic viewpoint to the one in which I was overawed by the sheer complexity of reality was a long and difficult one, and I had to part with some cherished beliefs. That is a painful thing to do, especially when they're beliefs that tell you you're smarter than everyone who believes differently, and that's something that's important to you.
Since then, I have resolved to follow Chesterton's advice -- to seek out strange ideas and happenings, to have respect for the richness and complexity of the real world. "There are more things on heaven and earth than are dreamt of in your philosophy." That is my anthem. The world is a wonderous place, and I welcome experiences that further open my eyes to it, that challenge my simple beliefs.
Where am I going with this?
For all of that experience, I am a Christian, on what I think are solid evidential grounds. And in most contexts I am considered a smart person, though I don't know that I particularly stand out on Hacker News. But there is a group of folks I run into time and again, frequently on the internet, who find it confusing that someone like me could believe such things as that.
When I was in grad school, one of the other students asked me what I was studying. I replied that while my coursework consisted of mathematics, outside of that I was also seriously pursuing computer science and theology. When I mentioned theology, he laughed and said, "That shouldn't take long!" In point of fact, I considered it the most demanding of the three subjects.
This reaction is common coming from atheists of a certain type. It is the idea that Christian ideas are simple and nonsensical, that Christian scholars are humbugs or hoodwinked, their work clever in a sad way. That Christians in general are not very smart, for how can they believe what they do, given all the obvious absurdities?
With utmost respect to the folks who believe this, I find it sad, and it makes me think of my days as a creationist. The world is just not as simple as you think it is. Christianity -- let alone all of religion! -- is a grand and complex and multifaceted thing, and whether or not you believe in it, there are wonderous and amazing ideas therein. Even if it is false, you do yourself an intellectual disservice to hold such a simple concept of it.
I have had wonderful dialogues with atheists over the years, and while I think they're wrong, I have found their ideas enriching. I would not understand God as well as I do were they not continually harping upon the problem of evil and suffering and forcing me to think about it. I suspect atheists who talked with intelligent Christians would be similarly enriched -- if not convinced, exposed to ideas worth thinking about. If you think theology is simple and straightforward and unenlightening, you really do not know what you are missing.
I extend you two invitations.
One is a shot in the dark. There is a contemporary professional philosopher named Alvin Plantinga, and he is Catholic. Most folks who hold this view have no idea he exists (but you might -- that's why it's a shot in the dark). He is an engaging fellow, smart and interesting. And while I do not always find him persuasive, he makes good arguments. If you think there are no good philosophical arguments for Christianity or no smart and rational Christians, google him and read some of his work. His wikipedia entry is a good place to start, to whet your appetite. I promise, he ain't no C.S. Lewis. He will expose you to some novel and chewy Christian ideas.
The other invitation is personal. I'm not professionally trained in Christian apologetics, but I am a layman who likes to think and read, and someone who likes to air out the mind. Send me an email with your most interesting atheistic idea -- you know, some really meaty stumper, some obvious absurdity that it makes no sense for Christians to swallow. And in my turn, I promise to show you some ideas and events and people that you have absolutely no idea existed -- help to air out your mind a bit. I promise to be interesting and intelligent, to respect the rules of rational discourse, not to attempt to convert you, and to generally try to make sure you have a good time.
It is a sad thing to be trapped in a simplistic little idea when reality is such a grand place.
Here's a comment I made on LW about Plantinga sometime ago:
"I remember stumbling across Plantinga's modal argument and going "what?" For convenience of onlookers, here it is in a more digestible form.
Premise 1: Besides our world, there are other "logically possible" worlds.
Premise 2: Some cheeseburgers are totally awesome.
Premise 3: To be totally awesome, a cheeseburger has to exist in all possible worlds, because being "logically necessary" sounds like a totally awesome quality to have.
Conclusion: Therefore, if a totally awesome cheeseburger is possible at all (exists in one possible world), then it exists in all possible worlds, including ours.
Well, ontological arguments are ancient and always seem like cheating. I am not a fan of them myself. But as I understand things, Plantinga's contribution is to formulate the ancient argument more rigorously. Even he does not claim the argument proves God exists -- only that it demonstrates God is either impossible or necessary. (Nor do I claim to agree with him on that point.) Particularly interestingly, the bit I presume you object to (though "facepalm" is admittedly a bit of an ambiguous criticism), that the possibility results in a necessity, is not the bit philosophers find objectionable.
If you wanted to really grapple with the argument as a means of growing your mind, not just satirize it without understanding what's going on, you should probably start with a more neutral summary of the state of things. Like this one: http://en.wikipedia.org/wiki/Anselms_argument#Plantinga.27s_...
Honestly, though, that's not the one I would have picked to pursue. I think that particular contribution of his is a minor thing, only interesting to professional philosophers in the first place. I had in mind something more major, like his notion of Warrented Belief. Or perhaps something amusing, like his evolutionary argument against naturalism.
But look, taking someone's weakest work, saying "Huh?", and satirizing it may feel good, but it's not a valid way to grow intellectually. Back when I was a creationist, if someone had said to me, "Look, you really ought to read The Demon-Haunted World -- even if you don't agree, it'll expose you to a totally new way of thinking about things," and instead of reading it, I went and found someone on a creationist website who made fun of some obscure little passage without really understanding it? I wouldn't gain anything by the experience.
Grapple with the original and the strongest form, or don't bother. Don't fool yourself.
I don't understand why you think I misunderstand Plantinga's argument. The facepalm refers to how it can be extended to demonstrate much more ridiculous statements than just the existence of God, therefore we can conclude it's wrong without worrying too much about which of the premises is faulty. If you think "the original and the strongest form" is supposed to work for God - increase our credence in the idea of God - but somehow fail to work for awesome cheeseburgers, then please enlighten me why. Because as far as I'm concerned, what I wrote was not a parody, but a completely valid cheese-o-logical proof using Axiom S5 and all these other things.
Oh, you're serious! I apologize for the critical response; I thought you were just making fun.
So, the ontological argument in its ancient form is very much vulnerable to the criticism you gave. When I encountered it in philosophy 101, it ran like roughly this:
(1) A being that exists is greater than a being that doesn't exist.
(2) Therefore, the greatest possible being, God himself, must exist.
We talked about it for a while, and then the prof rephrased it with "vacation spot", and we all laughed and moved on. It's a well-known critique, and it shows the argument must break down somewhere. We stopped there (as you did), but I think it's instructive to see why the argument doesn't work.
I came up with what I thought was the core problem: the argument doesn't prove what you think it does. It doesn't prove that God has to exist, only that your concept of him must include existence if it's to be coherent. For example, suppose I am at work fantasizing about the great boss I could have instead of the one I do have. For the idea to work, I must imagine that he really exists, and really works where I do, and is really in charge of my work. Those things are part of the concept. That doesn't mean they're true.
By contrast, when I imagine Mickey Mouse, I don't imagine that he really exists. "Is fiction" is one of the properties of the concept, and I'm okay with that. I don't need to imagine I can look him up in a phone book in order to enjoy stories about him.
So much for the logical.
There's a deeper problem with the argument, though, and it's this: I find it rather amusing that the philosopher thinks the best deity is well defined. I mean, has he ever tried, in practice, to define a best anything? When real people talk about real things, they often have a hard time agreeing on the best football team this year, or the best local chinese restaurant. The idea of a "best" or "greatest" something is incoherent in a vacuum. Best for what? Greatest in whose opinion?
Of course the philosopher might say, "No problem. The greatest possible being is the one everyone would agree is the greatest." I think it's rather optimistic of him to so blithely assume that's even logically impossible.
Imagine there was a sympathetic atheist out there. In his opinion, it's a very good thing that God doesn't exist, as his activity would make robust science so difficult -- and a world that has robust science is a much cooler than a world that has a deity. But he's sympathetic. He can see that people who believe in God often have better lives because of it. Some of those born again Christians really do turn things around, so the concept has to be good for something.
From his perspective, the best possible deity is a fictional one.
That rather explodes the argument, doesn't it?
Now, if you read Plantinga in the original (http://mind.ucsd.edu/syllabi/02-03/01w/readings/plantinga.ht...), he gives a long and entertaining summary of the ontological argument throughout history, famous criticisms and objections and his own attempt at repairing it. I cannot claim to have fully wrestled with it (I'm going to be chewing on it all morning, likely -- I hadn't read it closely before, thinking ontological arguments were inherently uninteresting sophistry), but here is what I think I do understand:
The argument runs this way:
(Definition 1) Call a being maximally excellent in a given world W if, in W, it is omniscient, omnipotent, and wholly good. (Note that the omniscience thing implies existence).
(Definition 2) Call a being maximally great if it were maximally excellent in every possible world.
(Premise) There is a possible world in which maximal greatness is exemplified. That is, in some (maybe imaginary but nonetheless coherent) world, a maximally great being exists.
(Conclusion) A being that existed in every possible world would have to be logically necessary.
(Conclusion) Such a being exists.
How does this differ from the ontological argument of yore, and what do I make of it?
I don't think it's trying to accomplish the same things, and I don't think it suffers from the same criticisms.
At a high level, it has a premise -- and once you unpack it all the way, that premise is equivalent to saying God is logically necessary. It's a premise. You're free to reject it. Plantinga claims to accept it (!), but notes that not everyone does (a heck of an understatement). He doesn't seem to care: the object of the discussion isn't to establish that God exists. The article opens and closes stating that the argument will not change anyone's mind, and that the reason we're even talking about it is because the discussion teaches us some interesting things about how to do philosophy -- things like, what do we mean by "exist" and "necessary" and "possible".
What Plantinga does claim the argument shows is that such a being must be logically necessary or logically impossible. God (so defined) is either essential or incoherent. I agree.
It handles my metric objections pretty well -- there's no subjectiveness in the words, all the definitions are nailed down pretty well.
How does it do with cheeseburgers? Let's try it.
(Definition 1) Call a cheeseburger all-yummy in a world W if all beings in W who taste it consider it to be clearly the yummiest cheeseburger they've ever had.
(Definition 2) Call a cheeseburger maximally yummy if it is all-yummy in all possible worlds.
(Premise) There is a possible world in which maximal yumminess is exemplified. That is, in some (possibly imaginary but nonetheless coherent) world, a maximally yummy cheeseburger exists.
(Conclusion) A cheeseburger which is all-yummy in every possible world must be logically necessary.
(Conclusion) There is an all-yummy cheeseburger in this world.
Now, I would say the argument is similarly valid. It establishes that the concept of a maximally yummy cheeseburger is either logically necessary or else incoherent. But in the case of cheeseburgers, it's easy to argue that it's incoherent. Of all the possible people in all the possible worlds, surely we can find two with incompatible tastes. We could imagine one guy who likes cheeseburgers better the more cheese they have, and another guy who likes his cheeseburgers with the lightest hint of cheddar possible. No one cheeseburger could satisfy both of them. Hence we reject the premise, saying the concept is incoherent.
But it doesn't exactly work the same way with God. People have tried through the centuries to say the three omni-s result in an incoherent being, and the modern consensus is that they've failed. It is possible that such a being is coherent.
Is such a maximally great being coherent or impossible? Many folks throughout history have said impossible, and Plantinga has no quarrel with them (well, he does, but not here or at least not much). And some theologans, Plantinga included, have said the idea is coherent. You might think that, for example, if you found some sort of first cause argument to be persuasive.
Personally, I have no opinion on the matter. I have not heard an argument either way that I find persuasive (though I do think it's theologically unnecessary and practically unlikely). In any case, it's not the sort of thing I care for -- I prefer evidence to armchair philosophy.
That kind of brings me back to why I recommended Plantinga for reading, though. I don't recommend him because he's apologetically persuasive -- indeed, I recommend him because he's not. He talks about whether things are reasonable or unreasonable, whether it is rational to be a theist or irrational to be a naturalist, and what rational even means. He's interesting reading if you think (where this discussion started) that religion as a whole is transparently irrational. I'm not trying to convert you; I wouldn't recommend an apologist, as that's an ideological attack. I recommend Plantinga because I think you'll find him interesting and alien.
Comments
G.K. Chesterton, in Orthodoxy, talked about the problem with crazy people. Talk to someone who believes crazy things -- say, a conspiracy theorist or a cultist -- and you will find that they are not, as you might suppose, without reason. They have a reason for everything. Indeed, they have too much reason -- an answer for every question, an explanation for every objection, a reason for everything from why their legs hurt to why the stars twinkle. The government did it.
It's easy to make up stories to explain experience. And they can be ruthlessly consistent stories. But the problem is that many of them are clearly wrong. One of the hallmarks of a crazy worldview is that it's flat and simple, playing the same notes over and over again, going back to the same explanations for everything. The person who believes the government is out to get him will use that as an explanation for everything, so his world is really quite shallow and sorry, telling only one sad little story.
Reality is not like that. It is complex and grand.
G. K. Chesterton talked about how to avoid this fate, and how to help people suffering it. The answer isn't to reason with them in their dark little rooms in a corner of reality. That does no good; they just run around their little well-trodden circuits. The answer is to go outside, get some fresh air, experience some of grandeur and complexity of the broader world.
I have actually had this experience myself. I was raised a young earth creationist, and from an early age was taught that anyone who believed in evolution must be very stupid, as it was so transparently rediculous and there were so many absurdities to it. I never questioned the proposition -- in retrospect quite silly -- that so many people beleived something so obviously false.
When I was in college, I took it upon myself to study the topic at a college level. I studied young earth creationists and old earth creationists and intelligent design and theistic evolution and naturalistic evolution. I learned about paleontology and biology and geology and astrophysics and philosophy and who knows what else. My husband was pursuing a degree in mathematical biology, studying mechanisms for spontaneous speciation, so I had some help from him.
And while it didn't take long for me to discard my young earth background -- a week or so, as I remember -- I expected that with a little bit of further study I could find the correct view. How hard could it be for an evidential person willing to commit a couple of years to the problem?
But I found that the more I studied it, the deeper the rabbit hole went. There is some weird stuff in origins. I mean really weird. The ancient landscape is alien, the history is remote. Folks from several sides made arguments I found persuasive, and after about three years of study, I came to the conclusion that nobody had the whole story. I resolved to consider it an open problem.
The journey from my very simplistic viewpoint to the one in which I was overawed by the sheer complexity of reality was a long and difficult one, and I had to part with some cherished beliefs. That is a painful thing to do, especially when they're beliefs that tell you you're smarter than everyone who believes differently, and that's something that's important to you.
Since then, I have resolved to follow Chesterton's advice -- to seek out strange ideas and happenings, to have respect for the richness and complexity of the real world. "There are more things on heaven and earth than are dreamt of in your philosophy." That is my anthem. The world is a wonderous place, and I welcome experiences that further open my eyes to it, that challenge my simple beliefs.
Where am I going with this?
For all of that experience, I am a Christian, on what I think are solid evidential grounds. And in most contexts I am considered a smart person, though I don't know that I particularly stand out on Hacker News. But there is a group of folks I run into time and again, frequently on the internet, who find it confusing that someone like me could believe such things as that.
When I was in grad school, one of the other students asked me what I was studying. I replied that while my coursework consisted of mathematics, outside of that I was also seriously pursuing computer science and theology. When I mentioned theology, he laughed and said, "That shouldn't take long!" In point of fact, I considered it the most demanding of the three subjects.
This reaction is common coming from atheists of a certain type. It is the idea that Christian ideas are simple and nonsensical, that Christian scholars are humbugs or hoodwinked, their work clever in a sad way. That Christians in general are not very smart, for how can they believe what they do, given all the obvious absurdities?
With utmost respect to the folks who believe this, I find it sad, and it makes me think of my days as a creationist. The world is just not as simple as you think it is. Christianity -- let alone all of religion! -- is a grand and complex and multifaceted thing, and whether or not you believe in it, there are wonderous and amazing ideas therein. Even if it is false, you do yourself an intellectual disservice to hold such a simple concept of it.
I have had wonderful dialogues with atheists over the years, and while I think they're wrong, I have found their ideas enriching. I would not understand God as well as I do were they not continually harping upon the problem of evil and suffering and forcing me to think about it. I suspect atheists who talked with intelligent Christians would be similarly enriched -- if not convinced, exposed to ideas worth thinking about. If you think theology is simple and straightforward and unenlightening, you really do not know what you are missing.
I extend you two invitations.
One is a shot in the dark. There is a contemporary professional philosopher named Alvin Plantinga, and he is Catholic. Most folks who hold this view have no idea he exists (but you might -- that's why it's a shot in the dark). He is an engaging fellow, smart and interesting. And while I do not always find him persuasive, he makes good arguments. If you think there are no good philosophical arguments for Christianity or no smart and rational Christians, google him and read some of his work. His wikipedia entry is a good place to start, to whet your appetite. I promise, he ain't no C.S. Lewis. He will expose you to some novel and chewy Christian ideas.
The other invitation is personal. I'm not professionally trained in Christian apologetics, but I am a layman who likes to think and read, and someone who likes to air out the mind. Send me an email with your most interesting atheistic idea -- you know, some really meaty stumper, some obvious absurdity that it makes no sense for Christians to swallow. And in my turn, I promise to show you some ideas and events and people that you have absolutely no idea existed -- help to air out your mind a bit. I promise to be interesting and intelligent, to respect the rules of rational discourse, not to attempt to convert you, and to generally try to make sure you have a good time.
It is a sad thing to be trapped in a simplistic little idea when reality is such a grand place.
Here's a comment I made on LW about Plantinga sometime ago:
"I remember stumbling across Plantinga's modal argument and going "what?" For convenience of onlookers, here it is in a more digestible form.
Premise 1: Besides our world, there are other "logically possible" worlds.
Premise 2: Some cheeseburgers are totally awesome.
Premise 3: To be totally awesome, a cheeseburger has to exist in all possible worlds, because being "logically necessary" sounds like a totally awesome quality to have.
Conclusion: Therefore, if a totally awesome cheeseburger is possible at all (exists in one possible world), then it exists in all possible worlds, including ours.
(facepalm happens here)"
Well, ontological arguments are ancient and always seem like cheating. I am not a fan of them myself. But as I understand things, Plantinga's contribution is to formulate the ancient argument more rigorously. Even he does not claim the argument proves God exists -- only that it demonstrates God is either impossible or necessary. (Nor do I claim to agree with him on that point.) Particularly interestingly, the bit I presume you object to (though "facepalm" is admittedly a bit of an ambiguous criticism), that the possibility results in a necessity, is not the bit philosophers find objectionable.
If you wanted to really grapple with the argument as a means of growing your mind, not just satirize it without understanding what's going on, you should probably start with a more neutral summary of the state of things. Like this one: http://en.wikipedia.org/wiki/Anselms_argument#Plantinga.27s_...
Honestly, though, that's not the one I would have picked to pursue. I think that particular contribution of his is a minor thing, only interesting to professional philosophers in the first place. I had in mind something more major, like his notion of Warrented Belief. Or perhaps something amusing, like his evolutionary argument against naturalism.
But look, taking someone's weakest work, saying "Huh?", and satirizing it may feel good, but it's not a valid way to grow intellectually. Back when I was a creationist, if someone had said to me, "Look, you really ought to read The Demon-Haunted World -- even if you don't agree, it'll expose you to a totally new way of thinking about things," and instead of reading it, I went and found someone on a creationist website who made fun of some obscure little passage without really understanding it? I wouldn't gain anything by the experience.
Grapple with the original and the strongest form, or don't bother. Don't fool yourself.
[Edit: If you're looking for something meaty of Plantinga's to read, try this: http://philofreligion.homestead.com/files/alspaper.htm . It's entertaining and friendly, and you'll probably learn something.]
I don't understand why you think I misunderstand Plantinga's argument. The facepalm refers to how it can be extended to demonstrate much more ridiculous statements than just the existence of God, therefore we can conclude it's wrong without worrying too much about which of the premises is faulty. If you think "the original and the strongest form" is supposed to work for God - increase our credence in the idea of God - but somehow fail to work for awesome cheeseburgers, then please enlighten me why. Because as far as I'm concerned, what I wrote was not a parody, but a completely valid cheese-o-logical proof using Axiom S5 and all these other things.
Oh, you're serious! I apologize for the critical response; I thought you were just making fun.
So, the ontological argument in its ancient form is very much vulnerable to the criticism you gave. When I encountered it in philosophy 101, it ran like roughly this:
(1) A being that exists is greater than a being that doesn't exist.
(2) Therefore, the greatest possible being, God himself, must exist.
We talked about it for a while, and then the prof rephrased it with "vacation spot", and we all laughed and moved on. It's a well-known critique, and it shows the argument must break down somewhere. We stopped there (as you did), but I think it's instructive to see why the argument doesn't work.
I came up with what I thought was the core problem: the argument doesn't prove what you think it does. It doesn't prove that God has to exist, only that your concept of him must include existence if it's to be coherent. For example, suppose I am at work fantasizing about the great boss I could have instead of the one I do have. For the idea to work, I must imagine that he really exists, and really works where I do, and is really in charge of my work. Those things are part of the concept. That doesn't mean they're true.
By contrast, when I imagine Mickey Mouse, I don't imagine that he really exists. "Is fiction" is one of the properties of the concept, and I'm okay with that. I don't need to imagine I can look him up in a phone book in order to enjoy stories about him.
So much for the logical.
There's a deeper problem with the argument, though, and it's this: I find it rather amusing that the philosopher thinks the best deity is well defined. I mean, has he ever tried, in practice, to define a best anything? When real people talk about real things, they often have a hard time agreeing on the best football team this year, or the best local chinese restaurant. The idea of a "best" or "greatest" something is incoherent in a vacuum. Best for what? Greatest in whose opinion?
Of course the philosopher might say, "No problem. The greatest possible being is the one everyone would agree is the greatest." I think it's rather optimistic of him to so blithely assume that's even logically impossible.
Imagine there was a sympathetic atheist out there. In his opinion, it's a very good thing that God doesn't exist, as his activity would make robust science so difficult -- and a world that has robust science is a much cooler than a world that has a deity. But he's sympathetic. He can see that people who believe in God often have better lives because of it. Some of those born again Christians really do turn things around, so the concept has to be good for something.
From his perspective, the best possible deity is a fictional one.
That rather explodes the argument, doesn't it?
Now, if you read Plantinga in the original (http://mind.ucsd.edu/syllabi/02-03/01w/readings/plantinga.ht...), he gives a long and entertaining summary of the ontological argument throughout history, famous criticisms and objections and his own attempt at repairing it. I cannot claim to have fully wrestled with it (I'm going to be chewing on it all morning, likely -- I hadn't read it closely before, thinking ontological arguments were inherently uninteresting sophistry), but here is what I think I do understand:
The argument runs this way:
(Definition 1) Call a being maximally excellent in a given world W if, in W, it is omniscient, omnipotent, and wholly good. (Note that the omniscience thing implies existence).
(Definition 2) Call a being maximally great if it were maximally excellent in every possible world.
(Premise) There is a possible world in which maximal greatness is exemplified. That is, in some (maybe imaginary but nonetheless coherent) world, a maximally great being exists.
(Conclusion) A being that existed in every possible world would have to be logically necessary.
(Conclusion) Such a being exists.
How does this differ from the ontological argument of yore, and what do I make of it?
I don't think it's trying to accomplish the same things, and I don't think it suffers from the same criticisms.
At a high level, it has a premise -- and once you unpack it all the way, that premise is equivalent to saying God is logically necessary. It's a premise. You're free to reject it. Plantinga claims to accept it (!), but notes that not everyone does (a heck of an understatement). He doesn't seem to care: the object of the discussion isn't to establish that God exists. The article opens and closes stating that the argument will not change anyone's mind, and that the reason we're even talking about it is because the discussion teaches us some interesting things about how to do philosophy -- things like, what do we mean by "exist" and "necessary" and "possible".
What Plantinga does claim the argument shows is that such a being must be logically necessary or logically impossible. God (so defined) is either essential or incoherent. I agree.
It handles my metric objections pretty well -- there's no subjectiveness in the words, all the definitions are nailed down pretty well.
How does it do with cheeseburgers? Let's try it.
(Definition 1) Call a cheeseburger all-yummy in a world W if all beings in W who taste it consider it to be clearly the yummiest cheeseburger they've ever had.
(Definition 2) Call a cheeseburger maximally yummy if it is all-yummy in all possible worlds.
(Premise) There is a possible world in which maximal yumminess is exemplified. That is, in some (possibly imaginary but nonetheless coherent) world, a maximally yummy cheeseburger exists.
(Conclusion) A cheeseburger which is all-yummy in every possible world must be logically necessary.
(Conclusion) There is an all-yummy cheeseburger in this world.
Now, I would say the argument is similarly valid. It establishes that the concept of a maximally yummy cheeseburger is either logically necessary or else incoherent. But in the case of cheeseburgers, it's easy to argue that it's incoherent. Of all the possible people in all the possible worlds, surely we can find two with incompatible tastes. We could imagine one guy who likes cheeseburgers better the more cheese they have, and another guy who likes his cheeseburgers with the lightest hint of cheddar possible. No one cheeseburger could satisfy both of them. Hence we reject the premise, saying the concept is incoherent.
But it doesn't exactly work the same way with God. People have tried through the centuries to say the three omni-s result in an incoherent being, and the modern consensus is that they've failed. It is possible that such a being is coherent.
Is such a maximally great being coherent or impossible? Many folks throughout history have said impossible, and Plantinga has no quarrel with them (well, he does, but not here or at least not much). And some theologans, Plantinga included, have said the idea is coherent. You might think that, for example, if you found some sort of first cause argument to be persuasive.
Personally, I have no opinion on the matter. I have not heard an argument either way that I find persuasive (though I do think it's theologically unnecessary and practically unlikely). In any case, it's not the sort of thing I care for -- I prefer evidence to armchair philosophy.
That kind of brings me back to why I recommended Plantinga for reading, though. I don't recommend him because he's apologetically persuasive -- indeed, I recommend him because he's not. He talks about whether things are reasonable or unreasonable, whether it is rational to be a theist or irrational to be a naturalist, and what rational even means. He's interesting reading if you think (where this discussion started) that religion as a whole is transparently irrational. I'm not trying to convert you; I wouldn't recommend an apologist, as that's an ideological attack. I recommend Plantinga because I think you'll find him interesting and alien.