Modal ontological argument

[polymath257]

Platinga doesn't make any basic mistakes in his argument.  The form is valid.  Hence it's somewhat misleading designation as a successful argument.  From it being possible that it's necessary that p, a person can infer that it's necessary that p.

The problem is in the assumption that it is possible that there is a necessary being. THAT is problematic. To be 'necessary' means it happens in all possible worlds and to be 'possible' means it happens in *some* possible world.

So what does it even mean to be possible to be necessary?

[Disagreeable]

It's invalid when he's using the same term in more than one way. This would change his X or Y, for example to an X* or Y* on some occasions but not others. So the inferencing would fail. When his terms are being used equivocally then his form is invalid.

But yes, the premises are also unsound the begin with.

So, basically, there isn't really anything charitable to say here besides the fact that he can at least spell words or something (I mean—there are plenty of times when theists can't even do that, even when English is their first language and they're neither dyslexic nor disabled—theists are just, generally, that thick. Sure, so are most atheists and agnostics. But, in general, theists are even dumber. But I digress. Plus, it's perhaps fairer to just say that they're more irrational and emotional. It's one thing to have an intellect and quite another thing to know how to use it and to not let your emotions corrupt it).

[emjay]

How is one to even get started learning about modal logic when according to the wiki, it seems a veritable pick 'n' mix of different types/uses? And what practical use does it have beyond these sorts of questions, or was it developed strictly for these types of questions? This goes out to anyone.

[Angrboda]

Meh. It's basically an analytic truth that if a necessary being exists in one possible world it exists in all possible worlds, as that's what to be necessary means. The big question is whether it does exist in some possible world which is equivalent to asking whether the idea of a maximally excellent being is coherent. I'd say no.

But there's another way to tackle it. Suppose that it is possible that there never was anything, that nothing ever existed. Is this possible? Of course. If that's the case then it's trivial to produce a modal ontological disproof of God.

1. There exists a possible world in which nothing exists;
2. If nothing exists in some possible world then a maximally excellent being does not exist in that world;
3. If a maximally excellent being does not exist in some possible world, then it does not exist in all possible worlds;
4. Therefore, a maximally excellent being does not exist in this world.

[Belacqua]

Meh.  It's basically an analytic truth that if a necessary being exists in one possible world it exists in all possible worlds, as that's what to be necessary means.  The big question is whether it does exist in some possible world which is equivalent to asking whether the idea of a maximally excellent being is coherent.  I'd say no.

But there's another way to tackle it.  Suppose that it is possible that there never was anything, that nothing ever existed.  Is this possible?  Of course.  If that's the case then it's trivial to produce a modal ontological disproof of God.

1. There exists a possible world in which nothing exists;
2. If nothing exists in some possible world then a maximally excellent being does not exist in that world;
3. If a maximally excellent being does not exist in some possible world, then it does not exist in all possible worlds;
4. Therefore, a maximally excellent being does not exist in this world.

If absolutely nothing exists in a world (including space, time, laws of nature, etc.) can that world be said to exist?

[Angrboda]

Meh.  It's basically an analytic truth that if a necessary being exists in one possible world it exists in all possible worlds, as that's what to be necessary means.  The big question is whether it does exist in some possible world which is equivalent to asking whether the idea of a maximally excellent being is coherent.  I'd say no.

But there's another way to tackle it.  Suppose that it is possible that there never was anything, that nothing ever existed.  Is this possible?  Of course.  If that's the case then it's trivial to produce a modal ontological disproof of God.

1. There exists a possible world in which nothing exists;
2. If nothing exists in some possible world then a maximally excellent being does not exist in that world;
3. If a maximally excellent being does not exist in some possible world, then it does not exist in all possible worlds;
4. Therefore, a maximally excellent being does not exist in this world.

If absolutely nothing exists in a world (including space, time, laws of nature, etc.) can that world be said to exist?

That's not what possible world means. Possible world simply means "some state of affairs." If possible worlds entailed ontological commitments, it would be a more difficult proposition using the semantics.

[polymath257]

How is one to even get started learning about modal logic when according to the wiki, it seems a veritable pick 'n' mix of different types/uses? And what practical use does it have beyond these sorts of questions, or was it developed strictly for these types of questions? This goes out to anyone.

Yeah, modal logic can be a mess.

The basic problem is how to deal with counter-factual claims. So, for example, "If Caesar did not cross the Rubicon, the Roman Republic would have lasted for another century".

In classical logic, this statement is *true* since Caesar *did* cross the Rubicon and a false implies anything.

But the statement "If Caesar did not cross the Rubicon, then the Roman Republic would have still fallen within the year" would *also* be true for the same reason.

The upshot is that any counterfactual implication is always true.

So the idea is that there are 'possible worlds' that are close to ours, but different. We can then ask in which of those possible worlds Caesar did not cross the Rubicon and ask what then happened.

Now, a bit more formal treatment defines a possible world as a 'maximal logically consistent system'. So, it is *logically* consistent to have a world in which Caesar did not cross the Rubicon, even though in the 'real world' he did. Notice that this is very different than the notion of a multiverse, for example. it is logically possible to have worlds where the laws of physics are very different.

This also then can deal with the notions of 'necessity' and 'possibility'. The definition of 'necessity' in this framework is 'happens in all possible worlds' and 'possibility' means 'happens in some possible world'.

The difficulties happen when you want to say things like 'it is possible that it is necessary that...' or some other situation where there is more than one use of 'possible' or 'necessary'. This inevitably leads to questions about relations between possible worlds. But different possible worlds are mutually contradictory (since they are maximal consistent systems).

[Neo-Scholastic]

A great book on this subject, that mentions Craig by name, is Dot, Dot, Dot: Infinity Plus God Equals Folly by Dr. James A. Lindsay who, like our own Polymath, is a PhD pure mathematican. Kurt Gödel had a similar proof of God’s existence; WLC likes to be a copycat, a source of revenue for him, a communications major from Wheaton College.

IMHO a few amatuers are capable of outperforming many professionals and having deep subject field knowlege generally does not mean someone has any special wisdom outside his or her domain of expertice. Truth is not source dependent.

[polymath257]

Meh.  It's basically an analytic truth that if a necessary being exists in one possible world it exists in all possible worlds, as that's what to be necessary means.  The big question is whether it does exist in some possible world which is equivalent to asking whether the idea of a maximally excellent being is coherent.  I'd say no.

But there's another way to tackle it.  Suppose that it is possible that there never was anything, that nothing ever existed.  Is this possible?  Of course.  If that's the case then it's trivial to produce a modal ontological disproof of God.

1. There exists a possible world in which nothing exists;
2. If nothing exists in some possible world then a maximally excellent being does not exist in that world;
3. If a maximally excellent being does not exist in some possible world, then it does not exist in all possible worlds;
4. Therefore, a maximally excellent being does not exist in this world.

This is a much more coherent argument than the one given by Platinga, I think.

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Meh.  It's basically an analytic truth that if a necessary being exists in one possible world it exists in all possible worlds, as that's what to be necessary means.  The big question is whether it does exist in some possible world which is equivalent to asking whether the idea of a maximally excellent being is coherent.  I'd say no.

But there's another way to tackle it.  Suppose that it is possible that there never was anything, that nothing ever existed.  Is this possible?  Of course.  If that's the case then it's trivial to produce a modal ontological disproof of God.

1. There exists a possible world in which nothing exists;
2. If nothing exists in some possible world then a maximally excellent being does not exist in that world;
3. If a maximally excellent being does not exist in some possible world, then it does not exist in all possible worlds;
4. Therefore, a maximally excellent being does not exist in this world.

If absolutely nothing exists in a world (including space, time, laws of nature, etc.) can that world be said to exist?

Yes. the empty set exists. And it has nothing in it. Don't confuse the container with the contents.

---

A great book on this subject, that mentions Craig by name, is Dot, Dot, Dot: Infinity Plus God Equals Folly by Dr. James A. Lindsay who, like our own Polymath, is a PhD pure mathematican.  Kurt Gödel had a similar proof of God’s existence; WLC likes to be a copycat, a source of revenue for him, a communications major from Wheaton College.

IMHO a few amatuers are capable of outperforming many professionals and having deep subject field knowlege generally does not mean someone has any special wisdom outside his or her domain of expertice. Truth is not source dependent.

And yet, WLC seems to think he can detect contradictions in the notion of infinity in exactly places that professionals detect no contradiction, only confusion on the part of WLC.

[Mister Agenda]

So the upshot is that if the maximal being exists in any possible world, it exists in all of them, and if it doesn't exist on one of them, it doesn't exist in any of them. So it's finally been proven: God is either real or not real.