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How do we know there's a God? What is he like?

Re: The Ontological Argument

Postby jimwalton » Wed Apr 11, 2018 4:26 pm

This argument comes from Dr. Alvin Plantinga. I was rephrasing it so it would be in my words and my understanding, but I'll just give it to you from his pen.

1. If God does not exist, His existence is logically impossible.
2. Uf God does exist, His existence is logically necessary.
3. Hence either God's existence is logically impossible or it is logically necessary.
4. If God's existence is logically impossible, the concept of God is contradictory.
5. The concept of God is not contradictory.
6. Therefore God's existence is logically necessary.

If God, a being a greater than which cannot be conceived, does not exist then he cannot come into existence. For if he did he would either have been caused to come into existence or have happened to come into existence, and in either case he would be a limited being, which by our conception of him he is not. Since he cannot come into existence, if he does not exist his existence is impossible. If he does exist he cannot have come into existence (for the reasons given), nor can he cease to exist, for nothing could cause him to cease to exist nor could it just happened that he ceased to exist. So if God exists his existence is necessary. Thus God's existence is either impossible or necessary. It can be the former only if the concept of such of being is self-contradictory in some way logically absurd. Assuming that this is not so, it follows that he necessarily exists.
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Re: The Ontological Argument

Postby Choking » Thu Apr 12, 2018 3:15 pm

1. If God does not exist, His existence is logically impossible.
2. If God does exist, His existence is logically necessary.
3. Hence either God's existence is logically impossible or it is logically necessary.
4. If God's existence is logically impossible, the concept of God is contradictory.
5. The concept of God is not contradictory.
6. Therefore God's existence is logically necessary.

Okay, this is looking better.

Can you expand the argument to prove premise 4? I don't see how that logically follows. A thing can be impossible without being self-contradictory. The Zanybird is an example of one such thing. Does premise 4 only apply to God, and why?

It also seems that your defense of premise 1 is as follows:

1A. God is unlimited.
1B. A being that is caused or happens would be limited.
1C. Therefore, God cannot be caused or happen (cannot come to be).
1D. Something that does not exist and cannot come to be is impossible.
1. If God does not exist, then God is impossible.

This is simplified, of course, but it seems to lay out the structure correctly. Can you defend premise 1B, then?
Choking
 

Re: The Ontological Argument

Postby jimwalton » Thu Apr 12, 2018 8:24 pm

> Can you expand the argument to prove premise 4? I don't see how that logically follows.

I can try, but it's a very complex argument that covers about 20 pages before it gets to the summary I listed above. Let me try.

He starts with Anselm's definition of God as "a being than which none greater can be conceived," which Plantinga tries to improve with "a being that which it is not logically possible that there be a greater," i.e., the greatest possible being. He relates that some philosophers object to the definition itself, saying that the notion of "a being than which it is not possible that there be a greater" is self-contradictory or nonsensical, but Plantinga argues that this is far from obvious. Other philosophers point out that it's impossible to state a set of principles enabling us to compare just any two beings with respect to greatness, let alone including "God." But just because we can't think of standards of comparison doesn't mean these beings don't exist.

He then addresses those who say that maybe a being exists that is greater than the greatest possible being. He works through the logic showing that this is contradictory and absurd.

After a couple pages of that, he goes into some examples. "It might be pointed out that not every grammatically proper replacement for variables like "A" and "B" in a statement like "If A exists and B does not, then A is greater than B" will yield a true sentence, even if the statement in question is true." (It sounds a little like your Zanybird example.) "It is true that if A can run the mile in 3.5 minutes and B cannot, then A is faster than B; but it scarcely follows that if nobody can run a mile in 3.5 minutes and George cannot, then nobody is faster than George. Even if it is true that A exists and B does not, A is great than B, it sure does not follow that if Nick exists and nobody does not, Nick is greater than nobody." So which substitutes for "A" and "B" must be ruled out? Any term that replaces "A" or "B" must be a referring term. (then there's huge and deep explanation.)

Back in. "I am inclined to think that when we speak of the being that which it is not possible that there be a great, we mean to be talking about a being such that *if it exists* there cannot be a great being; it does not follow that even if it fails to exist there cannot be a greater. If existence and nonexistent beings can be categorically compared, then perhaps the truth of the matter is this: if the being than which it is not possible that there be a greater really does exist, then indeed nothing can be greater than it; but if it does not (e.g., if it is merely fictional) then many things may be its superior. (Then more illustrations.) "Now what we need for a really thorough examination of this issue is a complete and accurate account of the predication of properties of nonexistent beings. Unfortunately I am not able to give such an account. Nonetheless this last form of the ontological argument is as specious as the preceding one.

(then comes the paragraph I wrote in the last post, and the argument listed in my post and your response. I'm just trying to give you the flow so you can follow his argument and hopefully, in the process, answer your questions without you having to read the book!)

(many pages of explanation. The best explanation for premise 4 is found in the paragraph I included in my last post: "It can be the former [God's existence is impossible] only if the concept of such a being is self-contradictory or in some way logically absurd." He seems to be referring back to a previous point about that if God's existence is logically impossible—because there is a being greater than the greatest imaginable being—then the concept of God is contradictory. Am I understanding it properly?)

> Can you defend premise 1B, then

A being that is caused is not self-sufficient but rather contingent and is dependent on some other causal mechanism or being for its existence. A being that happened can just as logically un-happen, and therefore his existence is always insecure and potentially subject to temporal limits, and he is therefore subject to at least limitation.
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Re: The Ontological Argument

Postby Choking » Sun Apr 15, 2018 10:53 am

Argument Structure:

God: a being that which it is not logically possible that there be a greater
1A. God is unlimited.
1B. A being that is caused or happens would be limited.
1C. Therefore, God cannot be caused or happen (cannot come to be).
1D. Something that does not exist and cannot come to be is impossible.
1. If God does not exist, His existence is logically impossible.
2. If God does exist, His existence is logically necessary.
3. Hence either God's existence is logically impossible or it is logically necessary.
4A. If God does not exist, then God is impossible.
4B. If God is impossible, then there exists a being greater than God.
4C. If there exists a being greater than God, then God is self-contradictory.
4. If God's existence is logically impossible, the concept of God is contradictory.
5. The concept of God is not contradictory.
6. Therefore God's existence is logically necessary.
.
.
.
> He seems to be referring back to a previous point about that if God's existence is logically impossible—because there is a being greater than the greatest imaginable being—then the concept of God is contradictory.

It sounds to me that Plantinga tries to obfuscate logical flaws in over-complicated definitions and pages of segues. The classical ontological argument is well-known to fail, and you cannot usually bypass the simpler version without making some strong assumptions about the organization of the universe.

I should also note, before continuing, that his definition of "greatness" is critical. "Existence" seems to be an important factor in this definition.

> if the being than which it is not possible that there be a greater really does exist, then indeed nothing can be greater than it; but if it does not (e.g., if it is merely fictional) then many things may be its superior.

This implies, to me, that a being that does not exist is considered to be less great than one that does. This is usually critical to the ontological argument.

I also wonder what definition of greatness is being used otherwise. Greatness normally can only apply to one or more specified qualities. He can be great in intelligence, power, size, etc. He might also be "great" in terms of existence, and that seems to be an important quality to be specified. However, I might define my Zanybird to have the greatest feathers, the greatest beak, etc. I don't see how "great" can be a catch-all term without bringing rise to contradictions. Can you provide a suitable definition?

Anyways, it seems to me that his argument is laid out more simply as follows:

4A. If God does not exist, then God is impossible.
4B. A thing that exists is greater than a thing that does not exist.
4C. If God is impossible, then there exists a being greater than God.
4D. If there exists a being greater than God, then God is self-contradictory.

Therefore,
4. If God does not exist, then God is self-contradictory.

But now we've shifted definitions just a bit from what I assumed we were working with earlier. Pretty much everything within does follow logically from our new definitions of "greatness" and "God". So, now, I need to ask you to defend premise 5. "The concept of God is not contradictory."

If God is so easily made contradictory by his nonexistence, and we do not know whether he exists, then I would suggest that we cannot claim to know that premise 5 is true. Can you defend it, under this definition of God?

This, and your definition of greatness, will help with premise 1B also, so I will respond to that later.
Choking
 

Re: The Ontological Argument

Postby jimwalton » Sun Apr 15, 2018 11:06 am

First of all, Plantinga is certainly not a logical obfuscator. He engages the brightest minds of our time, and his writings and logic are not easily brushed off, even by the best secular thinkers.

He readily admits that the ontological argument has its flaws. He doesn't put it forth as the argument to end all arguments, or even the best argument. I present it as one of the arguments for the existence of God because it is stronger than the counter argument. As I mentioned, there are about 8 arguments for the existence of God. All of them have their flaws, but each one of them, in my opinion, is stronger than the rebuttal. Taken together, they make a formidable case for the existence of God over the case against the existence of God. That's all I claim.

It's interesting in your laying out his argument "more simply," you changed it to being the obverse of the argument he presented.

> So, now, I need to ask you to defend premise 5. "The concept of God is not contradictory."

If I were speaking for me and not for Plantinga, I would condense 4 & 5 into a different premise: "God's existence is not logically impossible," and skip the part about self-contradiction. We all know that God's existence is not logically impossible. There are many ways that God's existence makes sense. So my conclusion, from this ontological argument, is that it is more reasonable to infer the existence of God than his nonexistence.
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Re: The Ontological Argument

Postby Choking » Tue Apr 17, 2018 4:33 pm

> We all know that God's existence is not logically impossible.

I would say that, under this definition, we don't know that. This is because, at the heart of the argument (as it appears to me), Plantinga is defining God as something that exists. This is why I want your definition of "great" - he is using this concept to prove that God's existence is a necessary part of his definition. However, if God is defined as something that exists, then proving his nonexistence would prove that he is logically impossible, and therefore we can't know either way until we first know whether he exists.

So how do you define "great"? This is crucial to the argument.

> It's interesting in your laying out his argument "more simply," you changed it to being the obverse of the argument he presented.

What have I changed in the argument that reverses it? Can you point to specific premises or structures that I've gotten wrong? If an argument fails simply from being logically structured, then it's a fallacious argument. What did I change? Where did I make a mistake?

Argument Structure:

God: a being that which it is not logically possible that there be a greater
1A. God is unlimited.
1B. A being that is caused or happens would be limited.
1C. Therefore, God cannot be caused or happen (cannot come to be).
1D. Something that does not exist and cannot come to be is impossible.

1. If God does not exist, His existence is logically impossible.
2. If God does exist, His existence is logically necessary.
3. Hence either God's existence is logically impossible or it is logically necessary.
4A. If God does not exist, then God is impossible.
4B. If God is impossible, then there exists a being greater than God.
4C. If there exists a being greater than God, then God is self-contradictory.
4. If God's existence is logically impossible, the concept of God is contradictory.
5. The concept of God is not contradictory.
6. Therefore God's existence is logically necessary.
Choking
 

Re: The Ontological Argument

Postby jimwalton » Tue Apr 17, 2018 7:42 pm

> I would say that, under this definition, we don't know that.

So what you are saying is that by people using reasoning (as I am), and observation of our known world (as I am), that it's logically impossible to infer the existence of a supreme being? Because if it is even remotely possible, empirically and logically, then it is not logically impossible. If there are arguments or evidences that could even possibly suggest it, then it's not logically impossible.

> Plantinga is defining God as something that exists.

He's not. He presents his case conditionally. He defines God as what God would be if He existed, and then proceeds to determine if the existence of such a being is a rational conclusion.

> This is why I want your definition of "great"

This actually comes from Anselm. I would surmise that by "great" he is connoting the ideal.

> What have I changed in the argument that reverses it?

Yeah, sorry, I wasn't thinking straight.
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Re: The Ontological Argument

Postby Choking » Wed Apr 18, 2018 1:39 pm

> So what you are saying is that by people using reasoning (as I am), and observation of our known world (as I am), that it's logically impossible to infer the existence of a supreme being?

It's logically possible to infer a lot - infer is not a strong term. I can infer the existence of the Zanybird, but it is still logically impossible. I cannot logically prove the Zanybird, however.

With respect to God, it is only even theoretically possible to prove his existence if he exists. If he does not, then it is not. You say "If God does not exist, His existence is logically impossible." Therefore, since we don't know whether he exists, we don't know whether he's logically impossible. We can't know, unless we know the first.

> Plantinga is defining God as something that exists.

> He's not. He presents his case conditionally. He defines God as what God would be if He existed, and then proceeds to determine if the existence of such a being is a rational conclusion.

Are you sure about this? It seems to me like he is.

He defines God as "greatest", and then says that something that exists is "greater" than something that does not. Therefore, God exists, by definition of "great". Is that not his reasoning?

> This actually comes from Anselm. I would surmise that by "great" he is connoting the ideal.

"Ideal" doesn't really help much. Ideal is still a very subjective and nonspecific idea. Unless, can you provide a suitable definition for "ideal"? I'm looking at dictionary definitions, but I'm not seeing one that necessarily applies that I'm certain you would agree with.
Choking
 

Re: The Ontological Argument

Postby jimwalton » Wed Apr 18, 2018 1:46 pm

> infer is not a strong term.

And yet "infer" doesn't denote "make up." It progresses through a mental process of logical and reasonable stages.

> I can infer the existence of the Zanybird

I'm not sure you can. You can manufacture it, but I'm not at all convinced you can infer it from evidence and reasoning.

> it is only even theoretically possible to prove his existence if he exists

It is possible to infer the existence of God from logic based on evidences. And therefore the existence of God is not logically impossible.

> Are you sure about this? It seems to me like he is.

Yes, I'm sure. Giving something a definition doesn't assume its existence, as we are all able to define "unicorn."

> "Ideal" doesn't really help much.

I don't define God using the term "ideal." Nor does Anselm or Plantinga. You seem to be deliberately obfuscating the common understanding of what God is and what that word/concept means to all of us as the supreme being.
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Re: The Ontological Argument

Postby Choking » Thu Apr 19, 2018 1:45 pm

> infer is not a strong term.
> And yet "infer" doesn't denote "make up." It progresses through a mental process of logical and reasonable stages.
> I can infer the existence of the Zanybird
> I'm not sure you can. You can manufacture it, but I'm not at all convinced you can infer it from evidence and reasoning.

So, can you give me an example of how one might infer the existence of God? Just so I know how you're defining it. I don't believe it's logically possible to prove the existence of God without subjective evidence. Is that what you're talking about?

> Yes, I'm sure. Giving something a definition doesn't assume its existence, as we are all able to define "unicorn."

I mean that he's trying to prove that God is necessary by definition. Plantinga said "then perhaps the truth of the matter is this: if the being than which it is not possible that there be a greater really does exist, then indeed nothing can be greater than it; but if it does not (e.g., if it is merely fictional) then many things may be its superior." He's showing that God existing is necessary for his "greatness", and therefore it's a part of God's definition. If God does not exist, then God is not great. That's how I interpret it, at least.

He's not offering any evidence for god, but rather logical arguments that are supported by the very definition of what God is supposed to be. If you disagree with this, then what part of his argument would you consider "evidence"?

> I don't define God using the term "ideal." Nor does Anselm or Plantinga. You seem to be deliberately obfuscating the common understanding of what God is and what that word/concept means to all of us as the supreme being.

All I did was ask for a definition! How can we discuss whether this God exists if we can't even define him properly? I just want to know what is meant by "great", because it has many definitions, most of which are context-dependent or subjective. I want to know which one we're using.
Choking
 

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