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Leibnizian Cosmological Argument

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SnoopDoug

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A Modal Cosmological Argument
« on: March 31, 2015, 11:02:47 am »
I take a version of the W-PSR and apply it to the LCA.  Thoughts are welcome.

 1. Possibly, whatever exists has an explanation of its existence, either in the necessity of its own nature or in an external cause. (Premise)

2. Possibly, the sum total of all contingent things C has an explanation of its existence. (Premise)

3. Necessarily, if C has an explanation of its existence, that explanation is found in an external cause. (Premise)

4. Necessarily, an external cause of C is something necessary N. (From 1 - 3)

5. Possibly, N exists. (Implied by 4)

6. Therefore, N exists. (By 5 and S5)
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aleph naught

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Re: A Modal Cosmological Argument
« Reply #1 on: March 31, 2015, 11:33:43 am »
1. Possibly, whatever exists has an explanation of its existence, either in the necessity of its own nature or in an external cause. (Premise)

Depending on what you mean by an explanation, this is either definitely false or at least not clearly true. What do you mean by an explanation?

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2. Possibly, the sum total of all contingent things C has an explanation of its existence. (Premise)

This seems very dubious, why think that there would be one single explanation for the sum of all contingent things? Why couldn't there be an infinite regress of contingent facts, where every fact has an explanation but no fact explains everything.

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3. Necessarily, if C has an explanation of its existence, that explanation is found in an external cause. (Premise)

So in other words, all contingent things have a cause. It's not clear to me that this is true. There could be contingent but atemporal things, right?

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Re: A Modal Cosmological Argument
« Reply #2 on: April 16, 2015, 03:29:39 pm »
I take a version of the W-PSR and apply it to the LCA.  Thoughts are welcome.

 1. Possibly, whatever exists has an explanation of its existence, either in the necessity of its own nature or in an external cause. (Premise)


How could something something cause its own existence?

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H.H.

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Re: A Modal Cosmological Argument
« Reply #3 on: April 16, 2015, 08:20:30 pm »
1. Possibly, whatever exists has an explanation of its existence, either in the necessity of its own nature or in an external cause. (Premise)

That kind of necessary existence doesn't seem possible to me, it doesn't even seem coherent. Swinburne argues that kind of metaphysical necessity is a logical contradiction and that seems about right. 
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aleph naught

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Re: A Modal Cosmological Argument
« Reply #4 on: April 17, 2015, 11:52:17 am »
1. Possibly, whatever exists has an explanation of its existence, either in the necessity of its own nature or in an external cause. (Premise)

That kind of necessary existence doesn't seem possible to me, it doesn't even seem coherent. Swinburne argues that kind of metaphysical necessity is a logical contradiction and that seems about right.

Would you mind explaining his argument?

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Re: A Modal Cosmological Argument
« Reply #5 on: April 17, 2015, 10:11:52 pm »
I take a version of the W-PSR and apply it to the LCA.  Thoughts are welcome.

 1. Possibly, whatever exists has an explanation of its existence, either in the necessity of its own nature or in an external cause. (Premise)

2. Possibly, the sum total of all contingent things C has an explanation of its existence. (Premise)

3. Necessarily, if C has an explanation of its existence, that explanation is found in an external cause. (Premise)

4. Necessarily, an external cause of C is something necessary N. (From 1 - 3)

5. Possibly, N exists. (Implied by 4)

6. Therefore, N exists. (By 5 and S5)

Hey SnoopDoug,
Here are some of my thoughts:

1. W-PSR logically implies S-PSR, so you can always exploit that fact and then skirt the use of S5 altogether. In fact, that would actually be preferable. That's because 'C' is not a rigid designator - it's going to denote different 'things' in different possible worlds. Thus it's possible that 'the explanation of C' will also denote different things in different possible worlds. You've only shown that, in every possible world, there's an explanation for C in that world. You haven't shown that it's the same explanation in all possible worlds. Thus N need not be a necessary entity.

2. One can reasonably doubt that "the sum total of all contingent things" even qualifies as a 'thing,' or that it has a single explanation. If there are an infinite number of contingent things, then there could be a regressive chain of explanations. (These things are debated in the 'grounding' literature, and so let's leave it at controversial.) For that reason, I'd prefer to use, as the explanans, the existence of a contingent world (or natural world).

Here's my version of a Leibniz-like cosmological argument. I claim that it's superior.

(0) Possibly, every contingent fact has an explanation (W-PSR).
(1) Every contingent fact has an explanation. (From W-PSR)
(2) There exists a natural world, and this fact is contingent.
(3) Thus, there is an explanation for the existence of the natural world.
(4) This explanation cannot be natural (i.e., it must be non-natural).
(5) It cannot simply be non-natural, it must be supernatural.

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H.H.

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Re: A Modal Cosmological Argument
« Reply #6 on: April 17, 2015, 11:58:50 pm »
1. Possibly, whatever exists has an explanation of its existence, either in the necessity of its own nature or in an external cause. (Premise)

That kind of necessary existence doesn't seem possible to me, it doesn't even seem coherent. Swinburne argues that kind of metaphysical necessity is a logical contradiction and that seems about right.

Would you mind explaining his argument?

It's a fairly involved argument so I'm not going to go through all of it(you can read it for yourself here or watch his presentation of it here), but one of the important points made in the argument is that if 'x does not exist' is a logical contradiction, that would entail that a great many logically possible propositions are in fact logically contradictory.

So for example, if 'god does not exist' is a logical contradiction, then that would entail that the proposition 'once upon a time there were no rational beings' would be a contradiction as well. How is it possible for a logically possible proposition to be a logical contradiction - that's a square circle.
« Last Edit: April 18, 2015, 12:07:20 am by H.H. »
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aleph naught

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Re: A Modal Cosmological Argument
« Reply #7 on: April 18, 2015, 11:51:17 am »
1. Possibly, whatever exists has an explanation of its existence, either in the necessity of its own nature or in an external cause. (Premise)

That kind of necessary existence doesn't seem possible to me, it doesn't even seem coherent. Swinburne argues that kind of metaphysical necessity is a logical contradiction and that seems about right.

Would you mind explaining his argument?

It's a fairly involved argument so I'm not going to go through all of it(you can read it for yourself here or watch his presentation of it here), but one of the important points made in the argument is that if 'x does not exist' is a logical contradiction, that would entail that a great many logically possible propositions are in fact logically contradictory.

So for example, if 'god does not exist' is a logical contradiction, then that would entail that the proposition 'once upon a time there were no rational beings' would be a contradiction as well. How is it possible for a logically possible proposition to be a logical contradiction - that's a square circle.

Oh, well then he's conflating consistency (logical possibility) with possibility (metaphysical possibility). The metaphysical necessity of P does not require that P be inconsistent. I don't think any theist would say that "God does not exist" is logically impossible.

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H.H.

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Re: A Modal Cosmological Argument
« Reply #8 on: April 18, 2015, 12:19:49 pm »
I don't think any theist would say that "God does not exist" is logically impossible.

You must not know very many theists...
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aleph naught

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Re: A Modal Cosmological Argument
« Reply #9 on: April 18, 2015, 12:25:42 pm »
I don't think any theist would say that "God does not exist" is logically impossible.

You must not know very many theists...

Hah okay, theists who aren't deeply confused about the meanings of these words. Yeah I've met theists who thought "God does not exist" was inconsistent, but they were also horribly incompetent.

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H.H.

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Re: A Modal Cosmological Argument
« Reply #10 on: April 18, 2015, 12:52:30 pm »
Hah okay, theists who aren't deeply confused about the meanings of these words. Yeah I've met theists who thought "God does not exist" was inconsistent, but they were also horribly incompetent.

Whether or nor theists take God as logically necessary, Swinburne's point is still valid. We'd have to wonder who exactly he's addressing if no prominent, serious theists take God's nonexistence as a logical contradiction, but still, even if it is a straw man, Swinburne knocked it down all the same.
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H.H.

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Re: A Modal Cosmological Argument
« Reply #11 on: April 19, 2015, 02:56:54 am »
Oh, well then he's conflating consistency (logical possibility) with possibility (metaphysical possibility).

How on earth does an oxford professor make such a flubbed argument and not get drummed out of the institution?  The man should be formally cashiered for such incompetence, he should be marched out to the middle of the Oxford commons and have his necktie clipped and his mortarboard  punched through and pulled down around his ears.  :P
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aleph naught

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Re: A Modal Cosmological Argument
« Reply #12 on: April 19, 2015, 11:30:58 am »
Oh, well then he's conflating consistency (logical possibility) with possibility (metaphysical possibility).

How on earth does an oxford professor make such a flubbed argument and not get drummed out of the institution?  The man should be formally cashiered for such incompetence, he should be marched out to the middle of the Oxford commons and have his necktie clipped and his mortarboard  punched through and pulled down around his ears.  :P

I donno, I guess every philosopher gets one :p I'm pretty sure theists generally think God's existence is necessary in the same way that people think H2O's being water is necessary.

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H.H.

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Re: A Modal Cosmological Argument
« Reply #13 on: April 19, 2015, 12:36:40 pm »
I'm pretty sure theists generally think God's existence is necessary in the same way that people think H2O's being water is necessary.

In the lecture Swinburne says that factual or ontological necessity is not enough for many theists because they cannot accept God as brute fact. He argues that the kind of metaphysical necessity most theists are after reduces to logical necessity - if the existence of God is logically possible then God exists in all possible worlds, existence is part of God's nature, God exists by the necessity of His own nature, etc. Swinburne claims God exists contingently as an ontologically necessary brute fact.


« Last Edit: April 19, 2015, 12:38:20 pm by H.H. »
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