Retired Boards (Archived)
Ontological Argument
Posted by: HIJ
« on: November 23, 2016, 03:25:08 PM »Late to the party on this. But if proper functionalism is correct, then a Knowno cannot exist.
Posted by: lucious
« on: November 10, 2016, 12:47:13 AM »Would a knowno be omniscient? I.e does it believe all true propositions and reject all false ones?
Posted by: joncantey
« on: August 19, 2016, 09:07:08 AM »James, if he isn't demonstrating it as false, then am I to take "we might not have a reason to accept it" as merely indicating potential for epistemic doubt? If that's the case, then that doesn't address the premise (which is ontological not epistemological). Am I misunderstanding the difference between these two in your statement?
Posted by: James
« on: August 19, 2016, 08:44:48 AM »...However, I think Van Inwagen casts doubt on the ability to evaluate that premise as being true. Not that he demonstrates it as false though; simply that we might not have a reason to accept it.
This seems to me not an attack on the MOA, since the premise being addressed is whether a MGB possibly exists (metaphysically or broadly logically possible)
Isn't "possibly, a maximally great being exists" that part of the MOA? Is looks to me like a challenge to one of the premises in the argument.
Posted by: joncantey
« on: June 20, 2016, 08:39:43 PM »...However, I think Van Inwagen casts doubt on the ability to evaluate that premise as being true. Not that he demonstrates it as false though; simply that we might not have a reason to accept it.
Is Van Inwagen’s assertion simply a more narrow restatement of the more general Atheological Premise (i.e. “it is possible that a MGB doesn’t exist”)? If so, doesn't this at best only leave us with a stalemate of epistemic uncertainty (like you seem to be concluding) -- i.e. agnosticism? Is the purpose of the Modal Ontological Argument (MOA) to address epistemic certainty?
This seems to me not an attack on the MOA, since the premise being addressed is whether a MGB possibly exists (metaphysically or broadly logically possible) -- not whether some contradictory premise is conceivable or even epistemically possible.
I think we have to look at other arguments for whether it is more rational to believe that a MGB possibly exists or whether a knowno exists.
Posted by: joncantey
« on: June 20, 2016, 11:33:29 AM »When talking about logical impossibilities, I should clarify that I'm only referring to things that are logically impossible in the universe in which we find ourselves. I know it's not a common idea, but I don't know if the logic that works in our universe, is actually universal. I can imagine other universes that are so wildly different from our own that there could exist things that we consider to be logically impossible.
For example, here in our universe, 2 dimensional molecules cannot exist. The third dimension may be small, but it would still exist. Such an object is easily possible in a universe with only two spacial dimensions. In that same way, other universes could yield possible, objects that are impossible in our universe. Instantiated contradictions (according to the laws of our universe) may be one of those things
I think you are referring to nomological possibility, not logical possibility. (See the Wikipedia page on Subjunctive Possibility. Don't ask me to explain the difference between logical possibility and metaphysical possibility, because I don't get it quite yet.)
Posted by: Atheist in Louisiana
« on: June 19, 2016, 10:06:37 PM »When talking about logical impossibilities, I should clarify that I'm only referring to things that are logically impossible in the universe in which we find ourselves. I know it's not a common idea, but I don't know if the logic that works in our universe, is actually universal. I can imagine other universes that are so wildly different from our own that there could exist things that we consider to be logically impossible.
For example, here in our universe, 2 dimensional molecules cannot exist. The third dimension may be small, but it would still exist. Such an object is easily possible in a universe with only two spacial dimensions. In that same way, other universes could yield possible, objects that are impossible in our universe. Instantiated contradictions (according to the laws of our universe) may be one of those things
For example, here in our universe, 2 dimensional molecules cannot exist. The third dimension may be small, but it would still exist. Such an object is easily possible in a universe with only two spacial dimensions. In that same way, other universes could yield possible, objects that are impossible in our universe. Instantiated contradictions (according to the laws of our universe) may be one of those things
Posted by: joncantey
« on: June 19, 2016, 09:17:56 PM »I don't believe that non-existent things can have effects.
OK, good, because I wasn't finding anything helpful along that route.
That's why such a thing would instantiate a contradiction, making it more powerful than something that is incapable of such an act.
So, you are asserting that an all-powerful being would be able to do the logically absurd? If you are, then he could create a knowno, and Inwagen's argument has no teeth. But, I don't think that omnipotence entails the ability to do the logically impossible. For example, square-circles and married-bachelors are absurdities and not "things", so not being able to make them doesn't mean that God can't do "any-thing". Similarly, an MGB can't make himself non-necessary or a quasi-MGB.
Posted by: Atheist in Louisiana
« on: June 19, 2016, 06:46:04 PM »QuoteThe way I see it, a being that doesn't exist, and yet has some effect is greater than one that does exist, regardless of the effect that existent being has.
Clarify how something that doesn't exist can have any effect (isn't that some kind of contradiction in terms)? Or are you trying to say that a MGB has no effect?
You understand surprisingly well. That's why a non-existent thing that does have an effect would be greater than one that does. Would you not agree that a thing capable of instantiating a contradiction would be greater than a thing that is incapable of such an act? It's trivially easy to pick up a brick if you exist, but it's far harder if you don't exist.
So, I'm admittedly lost now. It looks like I need to go read up on the various theories of existence, because I would have assumed that something that doesn't exist can't, by definition, have an effect. But until I read the current literature I can't yet tell you that you are wrong. You could save me some time if you could point to a definition/theory of existence that would entail a non-existence being's ability to affect the world in which it doesn't exist.
I don't believe that non-existent things can have effects. That's why such a thing would instantiate a contradiction, making it more powerful than something that is incapable of such an act.
Posted by: James
« on: June 16, 2016, 10:31:29 PM »James, I'm curious if Inwagen's knowno is a necessary being.
I don't think it is or needs to be in order for him to make his point.
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The ontological argument says that if it is possible the MGB exists, then MGB exists. It therefore can't be possible for something to exist that contradicts the first premise unless it is impossible for the first premise to be true. It doesn't seem like Inwagen's argument comes at this from the right angle. It seems like Inwagen's proposal begs the question by assuming that MGB isn't possible. Adding a premise that is logically incompatible with the first premise doesn't really do that as far as I can see.
If I'm understanding him correctly, I think he's just presenting a sort of counter argument to demonstrate an inability to evaluate the truth of the premise "possibly a MGB being exists." His argument seems to present an alternative, rival premise "possibly a knowno exists."
Yes, if it's possible a MGB exists, then the argument demonstrates a MGB is necessary. However, if it's possible that a knowno exists, then a MGB is impossible. It seems that he points out that whatever method used to establish the truth of the premise "possibly a MGB exists" can also be used to establish the premise that "possibly a knowno exists." So, if Van Inwagen is correct, then I think his point is that we can't evaluate the truth of the key premise of the modal ontological argument. So it's not that it's wrong, it's simply that we don't have reason to accept it as true either.
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I think to defeat the ontological argument you have to prove that an MBG is logically not possible.
I think that's correct as long as you accept the premise that a MGB possibly exists. However, I think Van Inwagen casts doubt on the ability to evaluate that premise as being true. Not that he demonstrates it as false though; simply that we might not have a reason to accept it.
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I don't see how Inwagen's argument does that, but perhaps I'm missing something.
No worries, I could be missing something too.
Posted by: joncantey
« on: June 13, 2016, 05:21:23 PM »QuoteThe way I see it, a being that doesn't exist, and yet has some effect is greater than one that does exist, regardless of the effect that existent being has.
Clarify how something that doesn't exist can have any effect (isn't that some kind of contradiction in terms)? Or are you trying to say that a MGB has no effect?
You understand surprisingly well. That's why a non-existent thing that does have an effect would be greater than one that does. Would you not agree that a thing capable of instantiating a contradiction would be greater than a thing that is incapable of such an act? It's trivially easy to pick up a brick if you exist, but it's far harder if you don't exist.
So, I'm admittedly lost now. It looks like I need to go read up on the various theories of existence, because I would have assumed that something that doesn't exist can't, by definition, have an effect. But until I read the current literature I can't yet tell you that you are wrong. You could save me some time if you could point to a definition/theory of existence that would entail a non-existence being's ability to affect the world in which it doesn't exist.
Posted by: aleph naught
« on: June 12, 2016, 10:59:03 PM »I think part of the answer here might have to do with the difference between epistemological possibility and ontological possibility, but I'm not an expert on the difference -- maybe someone can help me out. As I understand it, epistemological possibility is depicted in statements like "for all I know ___ exists or ___ doesn't exist". But ontological possibility identifies whether it is logically consistent for ___ to exist. Ontological impossibility requires something like logical incoherence, and I don't think that's been shown here regarding MGB's existence.
The difference is that metaphysical possibility (or ontological possibility, as you say), simply refers to possibility. It's what we're talking about when we say things like, "the Nazi's could have won WW2". In this way metaphysical possibility refers to some way things actually could be, or could have been. Epistemic possibility isn't actually a sort of possibility, rather it refers to a state of unknowing. To say that something is epistemically possible is simply to say that, for all we know, it is the case. We sometimes use "could" in this way to denote uncertainty, e.g. "there could be extra-terrestrial life, who knows".
Metaphysical possibility doesn't refer to logical possibility or coherence, that's something else entirely. Logical possibility simply refers to consistency. There are a lot of things that are consistent but impossible (note that both atheism and theism are both consistent, but only one could be true).
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Regarding my question about necessity, is it logically possible for a contingent, non-necessary being to exist if that entails that a necessary being can't exist?
Yup, it's possible. When we say God is a necessary being, we're saying that by his nature he has the property of existing necessarily. Similarly, we would say that a triangle by its nature has three sides. But, there have to actually be triangles for there to be three sided triangles. It doesn't make any sense to talk about non-existing things having properties. Likewise, God has to actually exist if he exists necessarily. And, whether or not he exists is exactly the question being debated.
As such, defining God as a necessarily existing being only entails that: if God exists, then God exists necessarily. Similarly, if there is a triangle, then it has three sides.
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That doesn't seem like a coherent solution. So, perhaps it is being implied that either the knowno is a necessary being, or that there is a quasi-MGB that knowno does know. Is that where this is going?
Hopefully I've explained clearly enough why it's not incoherent. No one would want to say that a Knowno necessarily exists or that there is a quasi-MGB (especially not the atheist!).
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Furthermore, I'm not sure how you can state that it is equally plausible in light of the other arguments for theism. I think Craig's position is that while these arguments are independent, they work together to increase the warrant for each other, thus reducing the charge of being ad hoc. I've never heard other arguments for knownos.
But there are also some very strong arguments against the existence, and even the possibility, of God. Think of the problem of evil, divine hiddenness, poor design and so on.
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As a side question what is the understanding behind "know" in Inwagen's argument? Does it entail the usual "justified/warranted true belief" idea? It seems like it would have to, because otherwise the knowno is simply wrong if MGB exists and they aren't logically incompatible. I've probably answered my own question, but there it is anyway. I just want to make sure we're all using the same terms here.
Yes, I think that's exactly what Van Inwagen wants to say. It's possible for a Knowno to exist, and if a Knowno exists then God does not (since knowledge requires true belief).
Posted by: Atheist in Louisiana
« on: June 12, 2016, 09:10:27 PM »QuoteThe way I see it, a being that doesn't exist, and yet has some effect is greater than one that does exist, regardless of the effect that existent being has.
Clarify how something that doesn't exist can have any effect (isn't that some kind of contradiction in terms)? Or are you trying to say that a MGB has no effect?
You understand surprisingly well. That's why a non-existent thing that does have an effect would be greater than one that does. Would you not agree that a thing capable of instantiating a contradiction would be greater than a thing that is incapable of such an act? It's trivially easy to pick up a brick if you exist, but it's far harder if you don't exist.
Posted by: joncantey
« on: June 12, 2016, 03:15:17 PM »I think part of the answer here might have to do with the difference between epistemological possibility and ontological possibility, but I'm not an expert on the difference -- maybe someone can help me out. As I understand it, epistemological possibility is depicted in statements like "for all I know ___ exists or ___ doesn't exist". But ontological possibility identifies whether it is logically consistent for ___ to exist. Ontological impossibility requires something like logical incoherence, and I don't think that's been shown here regarding MGB's existence.
For those interested, there's also a distinguishing between conceivably and epistemic possibility:
http://maverickphilosopher.typepad.com/maverick_philosopher/2010/01/coceivability-and-epistemic-possibility.html
Regarding my question about necessity, is it logically possible for a contingent, non-necessary being to exist if that entails that a necessary being can't exist? That doesn't seem like a coherent solution. So, perhaps it is being implied that either the knowno is a necessary being, or that there is a quasi-MGB that knowno does know. Is that where this is going?
Furthermore, I'm not sure how you can state that it is equally plausible in light of the other arguments for theism. I think Craig's position is that while these arguments are independent, they work together to increase the warrant for each other, thus reducing the charge of being ad hoc. I've never heard other arguments for knownos.
As a side question what is the understanding behind "know" in Inwagen's argument? Does it entail the usual "justified/warranted true belief" idea? It seems like it would have to, because otherwise the knowno is simply wrong if MGB exists and they aren't logically incompatible. I've probably answered my own question, but there it is anyway. I just want to make sure we're all using the same terms here.
For those interested, there's also a distinguishing between conceivably and epistemic possibility:
http://maverickphilosopher.typepad.com/maverick_philosopher/2010/01/coceivability-and-epistemic-possibility.html
Regarding my question about necessity, is it logically possible for a contingent, non-necessary being to exist if that entails that a necessary being can't exist? That doesn't seem like a coherent solution. So, perhaps it is being implied that either the knowno is a necessary being, or that there is a quasi-MGB that knowno does know. Is that where this is going?
Furthermore, I'm not sure how you can state that it is equally plausible in light of the other arguments for theism. I think Craig's position is that while these arguments are independent, they work together to increase the warrant for each other, thus reducing the charge of being ad hoc. I've never heard other arguments for knownos.
As a side question what is the understanding behind "know" in Inwagen's argument? Does it entail the usual "justified/warranted true belief" idea? It seems like it would have to, because otherwise the knowno is simply wrong if MGB exists and they aren't logically incompatible. I've probably answered my own question, but there it is anyway. I just want to make sure we're all using the same terms here.
Posted by: aleph naught
« on: June 12, 2016, 02:27:38 PM »James, I'm curious if Inwagen's knowno is a necessary being.
It wouldn't be nor would it have to be a necessary being. If a being that knows no MGB possibly exists, then no MGB exists. This follows from the same sort of S5 inference that Plantinga's modal ontological argument uses.
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The ontological argument says that if it is possible the MGB exists, then MGB exists. It therefore can't be possible for something to exist that contradicts the first premise unless it is impossible for the first premise to be true. It doesn't seem like Inwagen's argument comes at this from the right angle. It seems like Inwagen's proposal begs the question by assuming that MGB isn't possible. Adding a premise that is logically incompatible with the first premise doesn't really do that as far as I can see.
I think to defeat the ontological argument you have to prove that an MBG is logically not possible. I don't see how Inwagen's argument does that, but perhaps I'm missing something.
The first premise is that "if God possibly exists, then God exists". Did you mean the second premise, that "possibly, God exists"? Because yes, the point is precisely that maybe that second premise is impossible.
Just as God's possible existence entails his existence, God's possible non-existence entails his non-existence.
Neither the possibility of God's existence or his non-existence are any more plausible. So to infer that God exists because he possibly exists is special pleading, because we have just as much reason to think it's possible that he doesn't exist and that therefore he does not exist.
Or, as Peter Van Inwagen is saying, it's no more plausible that God possibly exists, than that a Knowno possibly exists.