Author:
Damoclese
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Date Posted: 04/ 1/02 10:45pm
In reply to:
Wade A. Tisthammer
's message, "Not yet." on 04/ 1/02 12:50pm
>
>All the line says is that it is possible for the
>greatest possible being to exist, a.k.a. statement G
>is possibly true. Remember, God (in this argument) is
>defined as “the greatest possible being.” The
>existence of a “greatest possible being” is by
>definition possible. Another way to look at it is
>that either <>G or ~<>G is true by the law of excluded
>middle. Since it hardly makes any logical sense to
>say that the greatest possible being cannot possibly
>exist (and thus ~<>G cannot be true), <>G (a.k.a.
>~[]~G) is true.
Okay, I'll take your word on it being definitionally possible, and I'll also take your word on what that line actually says since I seem to be missing the correct typeset to interpret all the symbols.
>>
>If I am understanding you correctly, you are saying
>that by switching premise #2 with <>~G (a.k.a. ~[]G).
>I too once believed that <>~G (which is equivalent to
>~[]G) was just as reasonable as <>G (which is
>equivalent to ~[]~G). So, I figured out I could
>replace premise #2 with ~[]G (“It is not necessary for
>God to exist,” or in other words, “It is possible for
>God not to exist”), get ~[]G together with premise #9
>and then use disjunctive syllogism to get []~G (God
>necessarily does not exist). Because I believed
>there’s no logical reason to favor ~[]~G over ~[]G, I
>believed I proved the argument defective since
>switching ~[]~G (premise #2) could be easily switched
>with ~[]G to logically prove that God does not exist.
>To illustrate, I’ll copy the symbolic logic thing
>again:
>cellspacing=0> 1. G
>⊃[]G | If God (on
>the definition above) exists, He exists
>necessarily. | 2.
>; ~[]~G | This states that G is not impossible,
>or <>G |
>
Those are the premises. The conclusion
>logically follows as demonstrated:
>cellpadding=1 border=0
>cellspacing=0> 3. []G
>⊃ G | If God necessarily exists, then he
>exists. | 4.
>[]G ∨ ~ []G | Law of Excluded
>Middle | 5.
>~[]G ⊃ []~[]G | Becker’s
>postulate applied to ~[]G |
> 6. []G ∨
>[]~[]G | 4,5
>substitution | 7.
>; []~[]G ⊃ []~G | 1, modal modus
>tollens | 8.
> []G ∨ []~G | 6,7
>substitution | 9.
>; []G | 7,2 disjunctive
>syllogism |
>colspan=2>——————————— | ∴
>G | 9, 3 modus ponens |
>
>Then I realized (two days later) that premise #9
>wouldn’t make any logical sense once premise #2 was
>switched with ~[]G (because premise #9 would then
>become []~G). []~G means that God (the greatest
>possible being) necessarily does not exist, which
>means that G does not hold true in any possible world.
>Put another way, []~G can be translated to mean, “The
>greatest possible being cannot possibly exist,” which
>is absurd because of its self-contradictory nature. If
>a being is possible (e.g. the greatest possible
>being) it can’t be impossible. The greatest possible
>being would by definition exist in at least some
>possible worlds. So switching premise #2 with ~[]G
>doesn’t and can’t prove that God does
>not exist because of the law of noncontradiction. So
>one reason <>G is favorable to <>~G in this argument
>is that <>G doesn’t lead to a contradiction within any
>of the premises in the argument, unlike <>~G. Another
>reason is that <>G logically must be true (again,
>unlike <>~G), because “the greatest possible being” is
>by definition possible. It would be a contradiction to
>say that the greatest possible being isn’t possible,
>whereas it wouldn’t break any rules of logic to say
>that it’s impossible for <>~G to be true.
I suppose you could underscore it with the assumption that you have the "greatest possible being" although the logic itself doesn't really rely on that assumption. If I change the underlying assumption to "Can God possibly exist?" rather than the greatest possible being existing being my underlying assumption, then the conclusion that God doesn't exist would be perfectly valid. I suppose then, to really have a thorough logical argument the underlying assumption of a greatest possible being would have to be subjected to the rigors of some logical system, for as I see it now, it seems the logic itself deals with possibility and necessity which in and of itself is only as good as the underlying premise or condition it is testing.
>
>Sorry about that. I hope this post does a better job
>of showing the symbols. The ontological argument
>relies only on two premises (which then logically
>follow to the conclusion of []G.):
They still aren't showing, probably because I lack the correct typeset, so I probably misinterpreted the line.
>
>>>———————————
>>> []G 7,2 disjunctive syllogism
>>
>>
>
>Again, “either God exists or doesn’t” wasn’t actually
>a premise, albeit ~G or G is true via the law of
>excluded middle. I do not simply “assume” that ~G
>can’t be true, I implicitly prove it using the
>rules of logic and the first two premises (if the
>first two premises are correct).
I assume this is also due to my lack of correct typeset since this comment is a part of the former.
>
>It seems you do not understand the argument. Yes,
>premise #1 is a conditional statement. Normally, we
>can’t prove anything with a conditional argument
>per se. That’s why premise #2 is added. The
>purpose of using symbolic logic was to have a formal
>proof of the validity of the argument. That is, I
>proved that if premise #1 and premise #2 is true, then
>the conclusion ([]G) must be true also. And this is
>indeed the case. The argument is still valid. The
>mere fact that I used a conditional is irrelevant.
I'm not arguing whether or not your argument is valid. (though I do have some problems with your underlying assumption that I will discuss later) This particular point I'm arguing is that the argument really doesn't matter given the nature of the conditional that is in effect. It isn't definitive proof of the existance of God. It is conditional proof that assumes he exists in the first place. (I'll address why it assumes he exists in the first place below).
>
>
>You are confusing the conclusion with the first
>premise. The first premise says, “If God exists, then
>he exists necessarily.” The conclusion is “God
>necessarily exists.” In the sentence that you quoted
>me, I was referring to the conclusion.
But the conclusion is dependant on the conditional. It isn't true that God necessarily exists except for the conditional if that begins the whole thing off. The first line must evaluate to true, if it doesn't, the conclusion is useless.
>
>
>>That's what it says, it
>>all rests on your first conditional premise, which is
>>what is being questioned in the first place.
>
>All the first premise says is that, “If God
>exists, then he exists necessarily.” This is because
>the greatest possible being would by definition have
>the greatest possible form of existence: necessary
>existence. So, If God exists, he necessarily
>exists; that’s the only thing that the first premise
>says. I don’t see how you are questioning this. The
>first premise does not presuppose the existence
>of God.
This is where we disagree. The first premise does presuppose the existance of God. (God defined here as some entity that is powerful) You yourself said it wouldn't make logical sense to say that the greatest possible entity cannot exist. It wouldn't make logical sense to say If God exists, he doesn't exist necessarily because you would deny the first part of your premise. Hence the statement If God exists automatically rules out the negative case namely if God exists he doesn't exist necessarily, or If god doesn't exist he exists necessarily because it generates a blatant contradiction.
I would be just as guilty of assuming an implied premise if I said "If God doesn't exist, he doesn't exist necessarily" because I know that I cannot possibly have the statement If God does exist, he doesn't exist necessarily for reasons which you have already named. I also cannot have If God doesn't exist, he exists necessarily. In fact there is only combination that will work that my argument will generate that I can keep and not have to throw out and that is If God doesn't exist, he doesn't exist necessarily.If I wanted to make my argument as valid as yours, my underlying premise could be that there doesn't exist a greater being.
By uttering the words "If God exists" you've committed yourself to the affirmitive case, and you haven't dealt with the negative case if that particular value isn't true. In computer programming as you've indicated you are interested in, it is a rare thing to see only one value accounted for in a program unless the programmer happens to know that is the only value that will come up in a case selection.
It ususally takes the form if so and so is true, then...
if not then...
But you haven't left any room for not in part because of your underlying assumption and your first premise which as I see it, assumes the existance of God allbeit implicitly.
>You appear to be confused on what the first premise
>actually says. Again, premise #1 just says,
>“If God exists, then he exists necessarily.”
>This is because the greatest possible being would have
>the greatest possible form of existence: necessary
>existence. I don’t see why this premise fails.
It fails in part because it implies by contradiction that the opposite case cannot be true via the first premise. It implies it's own conclusion. God not existing would clash horribly with the first premise of God existing. The conclusion would look monsterous if it read If God exists, and the conclusion read God doesn't exist.
The
>ontological argument is not simply a single syllogism
>where I immediately affirm the antecedent to utilize
>modus ponens or immediately state the negation of the
>converse statement to utilize disjunctive syllogism.
>Rather, I used a series of steps to obtain a formal
>proof that if premise #1 and premise #2 are correct,
>then []G must be true. The only way to deny []G in
>this argument is to deny either premise #1 or premise
>#2, (or both). But since both seem to be true by
>definition, I’m not too sure how you can accomplish
>that.
Well you left off the underlying assumption of the greatest possible being as well. I think I've shown that though the argument is valid, it isn't necessarily sound because it implies its own expectations. In fact, it is circular by implication. If I used the negative case with the negative assumption I mentioned, I would also classify it as circular by implication for it would be a strange thing to read If God doesn't exist, and then at the bottom read, he exists! Praises and saints be. No, unfortunately, my first premise would assume the outcome by implication provided that I threw out all contradictions it generated.
Damoclese
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