Is the ontological argument irrelevant?

[John Bunyan]

The ontological argument goes as follows:
1- It is possible that God exists
2- If it's possible that God exists, then God exists in some possible world.
3- If God exists in some possible world, then God exists in all possible worlds.
4- If God exists in all possible worlds, then God exists in the actual world.
5- Therefore, God exists.

Know the good thing in this argument is that it puts the burden of proof on the atheist, whom have to prove that it is not possible that God exists - meaning, that the concept of God is self-contradictory or impossible.

Now, I do not know of any sucessful argument to show that the very idea of God is absurd and impossible, so it seems that God does, matter fact, exist.

We could create an ontological argument against God's existence, however, which would go as follows:
1- It is possible that God doees not exist.
2- If its possible that God does not exist, then God does not exist in some possible world.
3- If God does not exist in some possible world, than God does not exist in all possible worlds.
4- If God does not exist in all possible worlds, than God does not exist in the possible world.
5- Therefore, it is possible that God does not exist.

The argument is coherent, so we need only to judge it's premises.
As a theist, it's my job to deny 1, and affirm that it is not possible that God does not exist, but how can this by done? Seems to me that to prove that God's existense is necessary in all possible worlds is an impossible task. How can I prove that something is impossible in all possible worlds? Seems to me that there is no way to prove that God must exist in all possible worlds without using steps 2 to 5 in the ontological argument to prove that God is a necessary being.

So, what is really important in the whole argument is wheter God's non-existence is possible in some world. But how can this be proven without other argument for God's existence?

The only way to prove God's existence is not impossible positively (for the lack of good arguments showing that the concept God is a incoherent one does not prove that it's not) is to prove that God does exist in some possible world, and to do this we must prove God's existence in the actual world (how can we prove that it is possible that God exists in any other possible world without reasoning in circles?), and to do this we need to use some other argument for God's existence, like the Moral Argument or the Teleological Argument.

What is the Ontological argument worth for, then, if it's crucial premiss cannot be proven without recurring to other arguments for God? Isn't the ontological argument better as a argument for God's aseity? Or am I just bad at thinking?

 

[Claudiu]

When talking about "possible worlds", what you're saying is that "x" is logically possible, or consistent. For example, I can say that "in a possible world, all objects are such that they are red". There is no logical contradiction. However, if a were to say that "in a possible world all objects are such that they are red and not red", then I have committed a logical contradiction. There are some atheists who say that God existing in any possible world is impossible because it is not logically possible, or consistent.

Also, there are other "Ontological Arguments", such as Anselm's and Descartes.

 

[Loopie]

Also, there are several other issues that we must address in the Ontological Argument (as you have stated it). I have heard it stated in many different ways, but I will simply respond to how you have stated it here.

First of all, you would have to define what you mean by 'God'. If you are presenting this ontological argument to a Muslim, a Christian, a Deist, and a Mormon, each of them will have a different idea of who God is. It does not at all say anything about the Triune God of Scripture.

Secondly, why is it the case that if God exists in some possible world, that he must exist in all possible worlds? We must go deeper in analyzing Statement 3 in order to see if such a conclusion is warranted.

Finally, this argument will never get you to the Triune God of Scripture. This does not meant that this argument is without merit. For instance, I wholeheartedly believe that God is the uncaused first cause, and so I consider the Cosmological Argument to have merit. But I also recognize that such an argument cannot go any further. It cannot specify that a 'particular' God exists. The Christian, the Deist, and the Muslim CAN all nod their heads and applaud the Cosmological Argument (as well as the Ontological Argument).

These are things you must keep in mind when presenting these arguments to someone, because this is exactly how they will respond to you.

 

[moral necessity]

The ontological argument goes as follows:
1- It is possible that God exists
2- If it's possible that God exists, then God exists in some possible world.
3- If God exists in some possible world, then God exists in all possible worlds.
4- If God exists in all possible worlds, then God exists in the actual world.
5- Therefore, God exists.

What is the Ontological argument worth for, then, if it's crucial premiss cannot be proven without recurring to other arguments for God? Isn't the ontological argument better as a argument for God's aseity? Or am I just bad at thinking?

I wouldn't use this argument. To me, Point 1 is the best point, because it shows that you cannot say emphatically that God does not exist.

I think Point 2 is the flaw: "If it is possible that God exists...then God exists...."
It goes from possibility to absolute.

At best, it should say,
2. "If it is possible that God exists...then God possibly exists in some possible world."
3. ...etc... (insert possibly)
4. ...etc... (insert possibly)
5. and you're back to the same point you started with..."Therefore God possibly exists."


Otherwise, any possibility is a reality somewhere:
1. It is possible that 3-headed monsters exist.
2. If it is possible that 3-headed monsters exist...then they exist in some possible world...


Blessings!

 

[John Bunyan]

When talking about "possible worlds", what you're saying is that "x" is logically possible, or consistent. For example, I can say that "in a possible world, all objects are such that they are red". There is no logical contradiction. However, is a were to say that "in a possible world all objects are such that they are red and not red", then I have committed a logical contradiction. There are some atheists who say that God existing in any possible is impossible because it is not logically possible, or consistent.

Also, there are other "Ontological Arguments", such as Anselm's and Descartes.

So to answer the "inverse" ontological argument (against God) I would have to prove that given any propositions in a possible world imagined by the atheist, it is impossible that God does not exist? How can I do that? That's my problem, the only way to prove that it's impossible that God does not exist is by proving that God exists in some possible world, and the only world for which I know how to argue in favor of God's existence is the real world. So why bother about the ontological argument at all? It all comes down to wheter it's possible that God exists or not (meaning, "Does God exist in some possible world?"), and we can't argue about that with consistency without using other arguments for God's existence in the real world.
The only way to respond to the argument against God is to say "Well, no, God exists in the real world, so he exists in all worlds". IS there other way to prove the proposition "It is possible that God does not exist" false?

Also, there are several other issues that we must address in the Ontological Argument (as you have stated it). I have heard it stated in many different ways, but I will simply respond to how you have stated it here.

First of all, you would have to define what you mean by 'God'. If you are presenting this ontological argument to a Muslim, a Christian, a Deist, and a Mormon, each of them will have a different idea of who God is. It does not at all say anything about the Triune God of Scripture.

I wouldn't use the argument without defining 'God' first, but I was too lazy to write a better definition before posting my question .

Secondly, why is it the case that if God exists in some possible world, that he must exist in all possible worlds? We must go deeper in analyzing Statement 3 in order to see if such a conclusion is warranted.

I believe this proposition is true, for if God exists in a possible world, being "Necessary Existence" a property of God, and being God the "maximally great being", or the "greatest imaginable being", it follows that God must exist in all possible worlds (in other worlds: God's inexistence is impossible). After all, it's greater to exist in all possible worlds than in just one.

Finally, this argument will never get you to the Triune God of Scripture. This does not meant that this argument is without merit. For instance, I wholeheartedly believe that God is the uncaused first cause, and so I consider the Cosmological Argument to have merit. But I also recognize that such an argument cannot go any further. It cannot specify that a 'particular' God exists. The Christian, the Deist, and the Muslim CAN all nod their hands and applaud the Cosmological Argument (as well as the Ontological Argument).

I know, and that's where I believe natural theology stops being useful. We cannot, I believe, believe that God is a trinitarian being through reason alone, we need revelation.

The ontological argument goes as follows:
1- It is possible that God exists
2- If it's possible that God exists, then God exists in some possible world.
3- If God exists in some possible world, then God exists in all possible worlds.
4- If God exists in all possible worlds, then God exists in the actual world.
5- Therefore, God exists.

What is the Ontological argument worth for, then, if it's crucial premiss cannot be proven without recurring to other arguments for God? Isn't the ontological argument better as a argument for God's aseity? Or am I just bad at thinking?

I wouldn't use this argument. To me, Point 1 is the best point, because it shows that you cannot say emphatically that God does not exist.

I think Point 2 is the flaw: "If it is possible that God exists...then God exists...."
It goes from possibility to absolute.

At best, it should say,
2. "If it is possible that God exists...then God possibly exists in some possible world."
3. ...etc... (insert possibly)
4. ...etc... (insert possibly)
5. and you're back to the same point you started with..."Therefore God possibly exists."


Otherwise, any possibility is a reality somewhere:
1. It is possible that 3-headed monsters exist.
2. If it is possible that 3-headed monsters exist...then they exist in some possible world...


Blessings!

Aren't propositions 1 and 2 semantically identical? Saying "it is possible that God exists" or "God exists in some possible world" is equivalent. After all, if a possible world is some description of reality, and something is possible, then in some description of reality, that something exists (meaning, for a proposition A to be possible, there must be some description of reality in which this proposition is true). So, if we say "It is possible that John Bunyan is the president of the US" is to say "In some description of reality, John Bunyan is the president of the US". So yeah, I agree, it is possible that a 3-headed monster exist in a possible world. Imagine a possible world in which genetic engineering has been perfected and some crazy dictator assembled an army of 3-headed monsters. Isn't this world logically possible?

 

[moral necessity]

The ontological argument goes as follows:
1- It is possible that God exists
2- If it's possible that God exists, then God exists in some possible world.
3- If God exists in some possible world, then God exists in all possible worlds.
4- If God exists in all possible worlds, then God exists in the actual world.
5- Therefore, God exists.

What is the Ontological argument worth for, then, if it's crucial premiss cannot be proven without recurring to other arguments for God? Isn't the ontological argument better as a argument for God's aseity? Or am I just bad at thinking?

I wouldn't use this argument. To me, Point 1 is the best point, because it shows that you cannot say emphatically that God does not exist.

I think Point 2 is the flaw: "If it is possible that God exists...then God exists...."
It goes from possibility to absolute.

At best, it should say,
2. "If it is possible that God exists...then God possibly exists in some possible world."
3. ...etc... (insert possibly)
4. ...etc... (insert possibly)
5. and you're back to the same point you started with..."Therefore God possibly exists."


Otherwise, any possibility is a reality somewhere:
1. It is possible that 3-headed monsters exist.
2. If it is possible that 3-headed monsters exist...then they exist in some possible world...


Blessings!

Aren't propositions 1 and 2 semantically identical? Saying "it is possible that God exists" or "God exists in some possible world" is equivalent. After all, if a possible world is some description of reality, and something is possible, then in some description of reality, that something exists (meaning, for a proposition A to be possible, there must be some description of reality in which this proposition is true). So, if we say "It is possible that John Bunyan is the president of the US" is to say "In some description of reality, John Bunyan is the president of the US". So yeah, I agree, it is possible that a 3-headed monster exist in a possible world. Imagine a possible world in which genetic engineering has been perfected and some crazy dictator assembled an army of 3-headed monsters. Isn't this world logically possible?

I don't know...in my mind, they are not equivocal statements. I guess I am seeing the something being "possible" includes an acknowledgment that it might not actually exist.

I would think it would read better like this...
1. God exists
2. If God exists, then he exists in some possible world...

The "if statement" in 2 has to include the entirety of the proposition in 1. That seems more tight to me.

The other way concludes that a reality must exist somewhere from a possibility of it existing. I guess that seems like a great leap to me. Do all possibilities require an actual reality of their existence somewhere? or just the possibility of their existence somewhere?

Blessings and prayers in your studies...

 

[OPC'n]

I say skip all possible points and get to the point

 

[Claudiu]

When talking about "possible worlds", what you're saying is that "x" is logically possible, or consistent. For example, I can say that "in a possible world, all objects are such that they are red". There is no logical contradiction. However, is a were to say that "in a possible world all objects are such that they are red and not red", then I have committed a logical contradiction. There are some atheists who say that God existing in any possible is impossible because it is not logically possible, or consistent.

Also, there are other "Ontological Arguments", such as Anselm's and Descartes.

So to answer the "inverse" ontological argument (against God) I would have to prove that given any propositions in a possible world imagined by the atheist, it is impossible that God does not exist? How can I do that? That's my problem, the only way to prove that it's impossible that God does not exist is by proving that God exists in some possible world, and the only world for which I know how to argue in favor of God's existence is the real world. So why bother about the ontological argument at all? It all comes down to wheter it's possible that God exists or not (meaning, "Does God exist in some possible world?"), and we can't argue about that with consistency without using other arguments for God's existence in the real world.
The only way to respond to the argument against God is to say "Well, no, God exists in the real world, so he exists in all worlds". IS there other way to prove the proposition "It is possible that God does not exist" false?

I'm having a hard time following what your worry is exactly. The Ontological Argument is an a priori argument that reasons its way to the necessary existence of God. The problem with the atheist is that he does not believe you can prove God. Note, proof, in philosophy, is different from everyday, ordinary usage. At the same time, some philosophers, such as Bertrand Russell, also believe that one can not prove the nonexistence of God.

 

[moral necessity]

I say skip all possible points and get to the point

Otherwise...it's pointless, right?

 

[Afterthought]

Do all possibilities require an actual reality of their existence somewhere? or just the possibility of their existence somewhere?

I thought that the language of possible worlds means that if something is possible, it exists in a possible world? But the way you put it does seem more tight, anyway.

3- If God exists in some possible world, then God exists in all possible worlds.

I'm not familiar with this ontological argument, but it seems here there is a hidden premise? Namely, one that allows one to conclude existence in some possible world to all possible worlds? I have seen a "possible world" ontological argument similar to this, but it reasons existence in some to existence in all possible worlds by stating that God existing in some possible world is not as great as existing in all possible worlds, so the greatest being imagined isn't the God that exists only in some possible world.

So to answer the "inverse" ontological argument (against God) I would have to prove that given any propositions in a possible world imagined by the atheist, it is impossible that God does not exist? How can I do that?

Since possibility is a logical possibility, it seems you would only have to show that God existing in some world does not bring a logical contradiction?

Edit:

I believe this proposition is true, for if God exists in a possible world, being "Necessary Existence" a property of God, and being God the "maximally great being", or the "greatest imaginable being", it follows that God must exist in all possible worlds (in other worlds: God's inexistence is impossible). After all, it's greater to exist in all possible worlds than in just one.

Just noticed this, so my comment about the hidden premise is already acknowledged. If that's the case then, perhaps another way to get around the inverse is noting that a maximally great being that exists in some possible world is greater than one that doesn't exist in any possible world? Or maybe....

2- If its possible that God does not exist, then God does not exist in some possible world.
3- If God does not exist in some possible world, than God does not exist in all possible worlds.

....note that "not exist[ing] in all possible worlds" does not exclude God "existing in some possible world," and then a maximally great being would exist in all possible worlds, and so the the inverse argument then behaves like a reductio? Of course, this hinges on God's existence being logically possible, and so perhaps reverts back to what was said at first. Unless a being that has logically possible existence is greater than one that does not (which then reverts back to what I just said above).

 

[Loopie]

Secondly, why is it the case that if God exists in some possible world, that he must exist in all possible worlds? We must go deeper in analyzing Statement 3 in order to see if such a conclusion is warranted.

I believe this proposition is true, for if God exists in a possible world, being "Necessary Existence" a property of God, and being God the "maximally great being", or the "greatest imaginable being", it follows that God must exist in all possible worlds (in other worlds: God's inexistence is impossible). After all, it's greater to exist in all possible worlds than in just one.

I think I see the one weakness or presupposition in statement number 3. Allow me to explain what I mean:

1) You agree that "God exists in some possible world"

2) You define 'God' as 'having necessary existence'

3) But if God, by your definition, has necessary existence, then it isn't just 'possible' that God exists; he MUST exist (in ALL worlds).

So do you see here how your presupposition (your definition of God as having necessary existence) automatically means that God MUST exist in ALL possible worlds? Based on your definition of God as "a being whose existence is necessary", let us take a look at your version of the Ontological Argument:

1- It is possible that "a being whose existence is necessary" exists. (*technically, it wouldn't be merely 'possible' for "a being whose existence is necessary" to exist, it would be necessary)
2- If it's possible that "a being whose existence is necessary" exists, then "a being whose existence is necessary" exists in some possible world.
3- If "a being whose existence is necessary" exists in some possible world, then "a being whose existence is necessary" exists in all possible worlds.
4- If "a being whose existence is necessary" exists in all possible worlds, then "a being whose existence is necessary" exists in the actual world.
5- Therefore, "a being whose existence is necessary" exists.

In the end, all you have done is 'proven' your assumption. You have assumed that God's existence (by definition) is necessary, and so your conclusion is: God must necessarily exist. Have you really accomplished anything?

 

[Loopie]

I would like to add that it seems the Ontological Argument is 'inaccurate' in its very first premise. Here is the premise:

1) It is possible that God exists.

Another version of this premise is from Plantinga: "It is possible that there is a being that has maximal greatness."

Yet if we are indeed talking about God in this premise, we are therefore talking about a God whose existence is necessary. By definition, God is a being whose existence is necessary.

So it would be inaccurate to say that "it is possible that God (a necessary being) exists". If we continue to define God as a being whose existence is necessary, then it is not merely 'possible' for him to exist, it would be NECESSARY. To say that it is possible for a necessary being to exist is to make a rather sillly statement, because BY DEFINITION such a being MUST exist (it is inaccurate to attach the word 'possible' to a being who by definition must exist). Rather, it is impossible for God NOT to exist.

This is the heart of the problem of the ontological argument (as it is presented in this discussion), because it essentially starts off with the assumption that God is a being who necessarily exists, downgrades him to 'possibly' existing, and then from there concludes its own assumption (that God necessarily exists). There may be other forms of the Ontological Argument that avoid this, but I do not know of any off the top of my head.

 

[Philip]

The only way to prove God's existence is not impossible positively (for the lack of good arguments showing that the concept God is a incoherent one does not prove that it's not) is to prove that God does exist in some possible world

Except that the burden of proof here is on the atheist to prove that He is not.

First of all, you would have to define what you mean by 'God'.

The greatest of all possible beings. Here's a different form of the argument:

1) God is the greatest of all possible beings.
2) Possible beings either have necessary or contingent existence.
3) God exists necessarily.
4) Therefore God exists.

Proof for premise 3)

5) Assume that God exists contingently.
6) Necessary existence is an absolute great-making property.
7) There is a possible being exactly like God with necessary existence.
8) But in this case, there is a possible being greater than God.
9) But there can be no being greater than God (1) therefore premise (5) is false.
10) Therefore God has necessary existence.

The major flaw in the argument, in my view, is that when presented to one already unconvinced of the existence of God, it usually comes across as either semantic or logical sleight-of-hand. I don't think there's a flaw in the argument itself as a logical one---the problem is that it has little rhetorical force. To present a good argument, you have to have logic, credibility, and a heart appeal, and the problem is that the OA always lacks the last.

 

[Bill The Baptist]

This is not neccesarily a bad argument, I just don't think it is very convincing when presented to atheists. I prefer the cosmological argument, which goes something like this:

1.Whatever begins to exist has a cause.
2.The Universe began to exist.
3.Therefore, the Universe had a cause

If we extrapolate this even further, we can reason that everything we observe around us had a cause. If we see a building or a machine, we know that someone somewhere designed and constructed it. Why should it be any different for living things?

 

[Philip]

I would like to add that it seems the Ontological Argument is 'inaccurate' in its very first premise. Here is the premise:

1) It is possible that God exists.

It isn't inaccurate, merely an understatement. Further, since the goal is to show that God must be a ncessary being, such an understatement is called for.

This is the heart of the problem of the ontological argument (as it is presented in this discussion), because it essentially starts off with the assumption that God is a being who necessarily exists, downgrades him to 'possibly' existing, and then from there concludes its own assumption (that God necessarily exists).

First off, in which of the premises is this stated or assumed? All we've done is to begin with the definition of God as the greatest of all possible beings ("that-than-which-no-greater-can-be-conceived" to use Anselm's term) and unpack that definition further.

If all that you mean by this is that the argument is circular, you are correct: all definitions are circular. All that the argument does is to unpack a definition---a definition that, in my view, is Scriptural. The whole point of the argument is that if we have a proper understanding of what we mean by the word "God" then we have to conclude that He is there.

 

[ChristianTrader]

This is not neccesarily a bad argument, I just don't think it is very convincing when presented to atheists. I prefer the cosmological argument, which goes something like this:

1.Whatever begins to exist has a cause.
2.The Universe began to exist.
3.Therefore, the Universe had a cause

If we extrapolate this even further, we can reason that everything we observe around us had a cause. If we see a building or a machine, we know that someone somewhere designed and constructed it. Why should it be any different for living things?

I think the cosmo argument is built on the onto argument. We have to defend the position that not everything is contingent (has a cause). That which is not contingent is necessary and eternal. That necessary being is God. Such is defended along the lines of "Something coming from nothing is incoherent and false." Therefore there is a necessary, eternal being. That being is what we call God.

The whole game is then identifying what meets the criteria of being eternal.

CT

 

[Bill The Baptist]

This is not neccesarily a bad argument, I just don't think it is very convincing when presented to atheists. I prefer the cosmological argument, which goes something like this:

1.Whatever begins to exist has a cause.
2.The Universe began to exist.
3.Therefore, the Universe had a cause

If we extrapolate this even further, we can reason that everything we observe around us had a cause. If we see a building or a machine, we know that someone somewhere designed and constructed it. Why should it be any different for living things?

I think the cosmo argument is built on the onto argument. We have to defend the position that not everything is contingent (has a cause). That which is not contingent is necessary and eternal. That necessary being is God. Such is defended along the lines of "Something coming from nothing is incoherent and false." Therefore there is a necessary, eternal being. That being is what we call God.

The whole game is then identifying what meets the criteria of being eternal.

CT

No matter what you believe, something must neccesarily be self-existent. Christians believe that God is self-existent, while atheists believe matter or energy or whatever is self-existent.

 

[Loopie]

Phil,

The very first premise: "It is possible that God exists", has in mind the definition of God as "a being whose existence is necessary". That is where the assumption is. By the way, I completely agree with what you have said about the weakness of the ontological argument, and that it is only correct in so far as a person has a correct understanding and definition of God. But let me also address the way you presented the OA:

The greatest of all possible beings. Here's a different form of the argument:

1) God is the greatest of all possible beings. (what does it mean to be 'great'?)
2) Possible beings either have necessary or contingent existence. (but a 'necessary' being isn't simply 'possible', it would be 'necessary')
3) God exists necessarily. (an assumption, which is correct if you already believe in the Bible, but incorrect if you believe in Greek pagan gods)
4) Therefore God exists.

Proof for premise 3)

5) Assume that God exists contingently.
6) Necessary existence is an absolute great-making property. (why is this the case, unless you assume that the Bible is true about how it presents God?)
7) There is a possible being exactly like God with necessary existence. (it wouldn't be possible, it would be necessary; having necessary existence means that you necessarily exist, not that you 'might' or 'possibly' exist)
8) But in this case, there is a possible being greater than God. (depends on definition of 'great')
9) But there can be no being greater than God (1) therefore premise (5) is false. (depends on definition of 'great')
10) Therefore God has necessary existence. (this is merely asserting what has already been assumed earlier, that God, by definition, is a being that necessarily exists)

Please understand Phil that I am not trying to completely discard the OA. Like I said before, I honestly believe that the OA and the Cosmological Argument are both useful, so long as they are based upon an understanding of the Triune God of Scripture. They can be used to point out to the unbeliever that 'something' is there, but you will then have to show them why that 'something' is the God of the Bible, and not the God of the Quran or the Book of Mormon.

I completely agree with your definition of God, and it is indeed scriptural. But it just goes to show that one must presuppose the God of scripture in order for arguments like the OA to make sense, or to hold water.

 

[ChristianTrader]

This is not neccesarily a bad argument, I just don't think it is very convincing when presented to atheists. I prefer the cosmological argument, which goes something like this:

1.Whatever begins to exist has a cause.
2.The Universe began to exist.
3.Therefore, the Universe had a cause

If we extrapolate this even further, we can reason that everything we observe around us had a cause. If we see a building or a machine, we know that someone somewhere designed and constructed it. Why should it be any different for living things?

I think the cosmo argument is built on the onto argument. We have to defend the position that not everything is contingent (has a cause). That which is not contingent is necessary and eternal. That necessary being is God. Such is defended along the lines of "Something coming from nothing is incoherent and false." Therefore there is a necessary, eternal being. That being is what we call God.

The whole game is then identifying what meets the criteria of being eternal.

CT

No matter what you believe, something must neccesarily be self-existent. Christians believe that God is self-existent, while atheists believe matter or energy or whatever is self-existent.

You are correct, to maintain coherency, one must believe that something is self-existent. The issue is can all claims be equally well defended. If the answer is yes, then one must defend such a claim. If the answer is no, then one needs to defend their view of what is eternal from attack from others with different views.

CT

 

[Philip]

what does it mean to be 'great'?

Greatness here has to do with inherent worship-worthiness.

The very first premise: "It is possible that God exists", has in mind the definition of God as "a being whose existence is necessary".

How so? The first premise is that God is the greatest of all possible beings---that is the definition. If you mean that this definition assumes the conclusion, you are correct---it's a deductive argument from that definition, after all. Maximal greatness logically entails necessary existence---that's the whole point of the argument. Attacking it on this point is like complaining that Starbucks serves too much coffee.

why is this the case, unless you assume that the Bible is true about how it presents God?

What are the properties that a maximally great being would have? In this case, would a maximally great being be contingent or necessary?

it wouldn't be possible, it would be necessary; having necessary existence means that you necessarily exist, not that you 'might' or 'possibly' exist

Missing the point here: necessity entails possibility.

They can be used to point out to the unbeliever that 'something' is there, but you will then have to show them why that 'something' is the God of the Bible, and not the God of the Quran or the Book of Mormon.

a) I haven't met many atheists who would take Islam or Mormonism seriously.

b) I am not trying to suggest that this is a convincing argument, merely that it is valid and sound.

 

[Loopie]

How so? The first premise is that God is the greatest of all possible beings---that is the definition. If you mean that this definition assumes the conclusion, you are correct---it's a deductive argument from that definition, after all. Maximal greatness logically entails necessary existence---that's the whole point of the argument. Attacking it on this point is like complaining that Starbucks serves too much coffee.

Why does maximal greatness logically entail necessary existence? Why must necessary existence be required in order to be maximally great? Mormonism teaches that God did not use to be God, and so God is not eternal (but they would no doubt believe him to be maximally great).

All I am saying is that different people will have a different view of what it means to be 'maximally great'.

I understand that the argument is deductive. It is rather similar to proving that all bachelors are men. Being a bachelor logically entails being a man. So even though the argument may be valid and sound, that is only if all parties agree on the same definition of 'bachelor' (or in the case of the OA, the same meaning of 'maximal greatness'). It doesn't prove that a bachelor exists, but it does show that IF a bachelor existed, it must necessarily be a man.

What are the properties that a maximally great being would have? In this case, would a maximally great being be contingent or necessary?

Depends on who you ask.

Missing the point here: necessity entails possibility.

It would seem though that necessity entails necessity. If something possibly exists, than that same thing possibly does not exist. Yet if something is necessary, then it is impossible for it not to exist. It must exist, and the opposite (it's non-existence) cannot be true. Possibility implies uncertainty as to something's existence. But if something necessarily exists than there cannot be any uncertainty at all.

a) I haven't met many atheists who would take Islam or Mormonism seriously.

b) I am not trying to suggest that this is a convincing argument, merely that it is valid and sound.

Are you suggesting that we Christians should also not take Islam or Mormonism seriously? Most well-known and outspoken atheists come from Western society, which was a predominantly Christian society. You probably won't find many open atheists in Muslim countries, and even Bart Ehrman said that he would only start criticizing the Quran (like he does the Bible) when he no longer values his life. Perhaps atheists don't take Islam seriously because of fear and intimidation.

 

[Philip]

Why does maximal greatness logically entail necessary existence?

That's what the argument demonstrates---it is inherently greater to have necessary existence than to have contingent existence. Hence why the God of the ontological argument cannot be the god of Mormonism.

I understand that the argument is deductive. It is rather similar to proving that all bachelors are men. Being a bachelor logically entails being a man. So even though the argument may be valid and sound, that is only if all parties agree on the same definition of 'bachelor' (or in the case of the OA, the same meaning of 'maximal greatness'). It doesn't prove that a bachelor exists, but it does show that IF a bachelor existed, it must necessarily be a man.

Except that in this case, the question is whether our understanding of the concept entails that you believe in its existence. The point of the argument is that "There is a God" is tautological---it's necessarily true.

If something possibly exists, than that same thing possibly does not exist.

Not at all. It is possible that X does not entail that it is possible that ~X.

 

[Loopie]

That's what the argument demonstrates---it is inherently greater to have necessary existence than to have contingent existence. Hence why the God of the ontological argument cannot be the god of Mormonism.

But it could be the God of Deism or Islam.

Except that in this case, the question is whether our understanding of the concept entails that you believe in its existence. The point of the argument is that "There is a God" is tautological---it's necessarily true.

It is only true if God does indeed exist as you define him, and this depends on which religious text you wish to hold up as your source of information.

Not at all. It is possible that X does not entail that it is possible that ~X.

In common usage, when you say that something is 'possible' you are implying that it 'may or may not be'. This is how the word is used, and the implication is unavoidable. If you wish to say that something MUST be, and cannot be otherwise, you use the word 'necessary'.

 

[Philip]

But it could be the God of Deism or Islam.

Which is why the project of perfect being theology continues beyond the OA.

It is only true if God does indeed exist as you define him, and this depends on which religious text you wish to hold up as your source of information.

I'm not sure I follow.

In common usage, when you say that something is 'possible' you are implying that it 'may or may not be'.

Ok, but this is the logical "possible." You seem to think that "possible" implies "contingent" whereas in modal logic, "possible" simply means "not impossible." To be metaphysically possible, all that is required in logical coherence. The point of the "possible" here is to rule out the arguments of some that even though a maximally great being would possess necessary existence, it is possible that the concept itself is incoherent.

I understand that colloquial usage has a range of meaning here, but in this case, "possibility" has a long history of usage in modal logic that is perfectly valid.

 

[Loopie]

I agree that the term 'possible' has a wide range of meanings, and I also agree that based on your use of the term, it is valid. You are absolutely right that we must go beyond the OA, even though the OA can certainly be useful in certain ways (much like the CA).

 

[John Bunyan]

I would like to add that it seems the Ontological Argument is 'inaccurate' in its very first premise. Here is the premise:

1) It is possible that God exists.

Another version of this premise is from Plantinga: "It is possible that there is a being that has maximal greatness."

Yet if we are indeed talking about God in this premise, we are therefore talking about a God whose existence is necessary. By definition, God is a being whose existence is necessary.

So it would be inaccurate to say that "it is possible that God (a necessary being) exists". If we continue to define God as a being whose existence is necessary, then it is not merely 'possible' for him to exist, it would be NECESSARY. To say that it is possible for a necessary being to exist is to make a rather sillly statement, because BY DEFINITION such a being MUST exist (it is inaccurate to attach the word 'possible' to a being who by definition must exist). Rather, it is impossible for God NOT to exist.

This is the heart of the problem of the ontological argument (as it is presented in this discussion), because it essentially starts off with the assumption that God is a being who necessarily exists, downgrades him to 'possibly' existing, and then from there concludes its own assumption (that God necessarily exists). There may be other forms of the Ontological Argument that avoid this, but I do not know of any off the top of my head.

I believe premiss (1) is in the argument for one could say "The existence of a necessary, all-powerful being is impossible", so what we're saying in (1) is "There is no inherent contradiction in the concept of God" (His existence is possible).

By the way, God must be necessary, otherwise His existence would be Contingent, wouldn't it? (or am I wrong?)

When talking about "possible worlds", what you're saying is that "x" is logically possible, or consistent. For example, I can say that "in a possible world, all objects are such that they are red". There is no logical contradiction. However, is a were to say that "in a possible world all objects are such that they are red and not red", then I have committed a logical contradiction. There are some atheists who say that God existing in any possible is impossible because it is not logically possible, or consistent.

Also, there are other "Ontological Arguments", such as Anselm's and Descartes.

So to answer the "inverse" ontological argument (against God) I would have to prove that given any propositions in a possible world imagined by the atheist, it is impossible that God does not exist? How can I do that? That's my problem, the only way to prove that it's impossible that God does not exist is by proving that God exists in some possible world, and the only world for which I know how to argue in favor of God's existence is the real world. So why bother about the ontological argument at all? It all comes down to wheter it's possible that God exists or not (meaning, "Does God exist in some possible world?"), and we can't argue about that with consistency without using other arguments for God's existence in the real world.
The only way to respond to the argument against God is to say "Well, no, God exists in the real world, so he exists in all worlds". IS there other way to prove the proposition "It is possible that God does not exist" false?

I'm having a hard time following what your worry is exactly. The Ontological Argument is an a priori argument that reasons its way to the necessary existence of God. The problem with the atheist is that he does not believe you can prove God. Note, proof, in philosophy, is different from everyday, ordinary usage. At the same time, some philosophers, such as Bertrand Russell, also believe that one can not prove the nonexistence of God.

My problem is not with the ontological argument per se, but with it's opposite. It seems to me that the only important proposition is (1), and if I present the ontological argument, the atheist then has to prove that God is, in some way, a incoherent idea. But if someone says "Ok, but it is also possible that God does not exist, so your own beloved ontological argument can be used to prove that God does not exist", how can I respond? Is there any way to prove that "It is possible that God does not exist" is a false proposition without giving another argument to God's existence (proving that He does exist in the real world, so must exist in all worlds)? How can I respond to such a comeback?

 

[Philip]

"It is possible that God does not exist" is a false proposition without giving another argument to God's existence

That's exactly what the OA deals with: if God exists, in one possible world, He exists in all. That is why we end up with the conclusion that God is a necessary being. The burden of proof to negate this conclusion would have to demonstrate either a) that necessary existence is not an absolute great-making property (absurd) b) that God's existence is not possible (ruled out by definition in the first premise).

 

[Loopie]

It seems to me, that when I look at the Ontological Argument, a few things come to mind:

1) If ANY being is defined as having 'necessary existence', then it must exist. This follows from the OA, since the OA argues that there is some possible world (alternate universe) where a being of necessary existence exists. If there is some possible world where such a being exists, then this must be true in all possible worlds (I think we need to go into more detail about why, if something is true in some possible world, that it MUST be true in ALL possible worlds).

2) I understand that some opponents of the OA argue that they can 'conceive' of beings that don't exist. I mean, there are numerous super heroes and super beings in comic books that simply do not exist. Is there some alternate universe where these things DO exist? If the atheist believes that a maximally great being (with necessary existence) is just a figment of human imagination, then it does not necessarily follow that such a being exists. I mean, it would seem that the atheist could liken the conception of a maximally great being with the concept of a comic book character. Simply because all-powerful, god-like characters exist in comic books does not mean that they exist in reality (or even in some other possible world). Essentially, the person who uses the OA must work with his opponent to figure out what it means to be a maximally great being. Interestingly, this would require a Christian to go to scripture first (a sort of presuppositional apologetics), in order to describe what a maximally great being looks like. The OA is only really helpful or useful in light of what we as Christians know from scripture about God (the maximally great being).

 

[Philip]

If ANY being is defined as having 'necessary existence', then it must exist.

That's the key: you can't simply define a being as being necessarily existent. You have to prove that the essence of that being requires that it be necessarily existent. In other words, you start with the concept of God as maximally great (indisputable) and reach the conclusion that He is necessarily existent.

I understand that some opponents of the OA argue that they can 'conceive' of beings that don't exist.

This is, in essence, Gaunilo's argument "on behalf of the fool." He brings up the example of the greatest possible island. However, why would necessary existence make an island better? There is nothing in the nature of islands that requires that they exist in order to be greater. But what is the essence of a being? To be. Necessary existence, in the case of a being, would most certainly be an absolute great-making property.

 

[Loopie]

Believe me, I am not a big fan of Gaunilo's argument. I don't think bringing up the greatest possible island idea does anything to really address the OA.

There is one thing that came to mind during our discussion. Much like the CA, the OA seems to be valid (or at least has yet to be proven invalid). And even though these arguments do not specifically describe the Triune God of Scripture, they seem to be akin to General Revelation. That is, the validity and soundness of these arguments for the existence of God testify to the fact that God has revealed himself to the world (generally speaking) in such a way that the unbelievers are without excuse, and cannot fully dismiss or discard the truth that they suppress (they cannot invalidate the OA and the CA). Though these arguments for God's existence do not specifically reveal the Triune God of Scripture, they reveal enough of Him so that the unbeliever is condemned by ignoring the evidence of his creator.

Thoughts?