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Friday, February 10, 2006

The Formal Presuppositional Argument?

I noticed that Dusman, an administrator over at Gene Cook's forum formalized the Presuppositional argument* in the thread about John Loftus’ appearance on the Atheist Hour:

1) For X to be the case, Y has to be the case.
2) X is the case.
3) Therefore, Y is the case.

Read that first premise to yourself slowly a few times. Does that seem strange to anyone? This is not the standard language used to make a conditional statement. The standard language would be:

"If X is the case, then Y is the case."

But why isn’t the presuppositional argument stated clearly as an if-then conditional? Why is it stated as a for-has? This presuppositional phrasing is awkward- making it difficult to determine which is the antecedent and which is the consequent. But is the meaning of the statement changed if the statement changed directly to an if-then conditional, as shown above? This translation doesn’t seem to be completely accurate- in the presuppositional for-has conditional, the truth of X is dependent on the truth of Y. But in the if-then condition, the truth of Y is dependent on the truth of X. These statements are not equivalent, so clearly it’s not accurate to translate the presuppositional for-has conditional directly into an if-then.

But what if X and Y were flipped? In this event, the conditional would read:

“If Y is the case, then X is the case.”

Here we see that the truth of X is dependent on the truth of Y, just as in the presuppositional for-has conditional. So, the two wordings of the statement are equivalent, and we are now able to use a much clearer if-then conditional to reexamine the presuppositional argument:

1) If Y is the case, then X is the case.
2) X is the case.
3) Therefore, Y is the case.

Now we can easily see that this argument takes the form of the logical fallacy Affirming the Consequent. It makes sense why Dusman needed to use the for-has phrasing that he did to hide this fallacy- although grammatically confusing, the presuppositional use of for-has results in listing the consequent prior to the antecedent in the conditional statement, giving the illusion of a perfectly valid modus ponens.

But why would the presuppositionalist risk a logical fallacy just to make his argument? Why not simply construct a valid modus ponens and stand by it? My guess is that he then runs the risk of being accused of a more informal non sequitur, as many explanations can be given for X being the case without calling upon Y. But since the truth of X is uncontested by all, and in fact presupposed by any who would seek to argue logically, the presuppositionalist tries to use this acceptance of X as a wedge to force acceptance of Y, by making the truth of X dependent on the truth of Y. Unfortunately, this is a fallacious argument as I’ve already noted.

I’m inclined to suppose that this underlying error may be the reason why the presuppositional argument is so rarely displayed formally- I’m frankly surprised that Dusman did so without provocation, although he was in the comfortable setting of a presuppositionalist forum. This was the first time that I’ve seen the for-has phrasing of the major premise- on the one occasion that Paul Manata formalized the same argument, he used a slightly different strategy:

1) If X is the case, then Y is the case (since Y is the precondition for X)
2) X is the case.
3) Therefore, Y is the case.

I’m sure that by this point, you don’t need my help to see that this is committing the same error. By inserting additional information about the relationship between X and Y parenthetically, Paul has made the truth of X dependent on the truth of Y, and thus enters into the same fallacy as Dusman above.

Of course, this is just based on the postings of two individuals who claim presuppositional apologetic strategies. They may be incorrect in their formulation of the presuppositional argument, in which case I look forward to seeing the real McCoy. Or maybe there are some subtleties to the argument that I’ve missed. Either way, I’m eagerly anticipating edification.

* in the presuppositional argument, X=logic and Y=God

Post a Comment


17 Comments:

At 2/10/2006 5:19 PM, Blogger John W. Loftus declaimed...

Don't forget to check out my response to presuppositionalism, here.

 
At 2/10/2006 5:21 PM, Blogger Zachary Moore declaimed...

Thanks, John. My comment there was the kernel which became this post.

 
At 2/11/2006 10:33 AM, Blogger Bahnsen Burner declaimed...

Dusman pulled this silly tripe on me as well when he and I butted heads in "The Bible as Evidence" thread. My link will take you to page 5 of that conversation where Dusman unpockets the very "argument" he pulled on you. He got it from Michael Butler, who wrote a chapter called “The Transcendental Argument for the Existence of God" in S. Schlissel’s The Standard Bearer: A Festschrift for Greg L. Bahnsen, pp. 65-124. Butler presents his model on p. 79, where it reads very closely to Dusman's version:

For x (some aspect of human experience) to be the case, y must also be the case since y is the precondition of x. Since x is the case, y is the case.

Dusman did not offer much of a response to any of the criticisms I raised against it.

 
At 2/11/2006 12:30 PM, Blogger Zachary Moore declaimed...

Ah. I seem to recall that Paul Manata was, at least at one time, a student at Bahnsen Theological Seminary, where Butler teaches philosophy and apologetics. This would explain why Paul's argument is much closer to Butler's phrasing.

I suppose, then, if Paul was a student of Butler's his claims of having contact information for Michael Martin derive from Butler's communications with Martin.

 
At 2/11/2006 1:31 PM, Blogger Aaron Kinney declaimed...

Well done Zach. I never thought about the argument like that before, nor did I see the fallacy of affirming the consequent before now.

 
At 2/16/2006 10:04 AM, Blogger Zachary Moore declaimed...

No presuppositionalists want to weigh in on this before it slips off the front page? Well, I guess I had it right, then.

 
At 2/18/2006 8:11 PM, Blogger Paul Manata declaimed...

First off, show me the logic book that allowed you to translate it that way. Or, were you just shooting in the dark? You were, weren't you? You tried to get smart and just make things up as you went as if your translation was a valid one. There are rules to translating, you know?

Anyway, Dustin said, For X to be the case Y *has* to be the case. This shows that Y was the necessary proposition. When translating a conditional proposition, you place the sufficient condition in the antecedent position and the necessary condition in the consequent position.

Now, it is possible that you could have wanted to translate Dustin's as a bioconditional, depending on what he said. But in that case you would still have had the *has* proposition in the consequent position, but you would just have notated it differently:

x <--> y

x

/y

 
At 2/19/2006 8:12 PM, Blogger Zachary Moore declaimed...

Paul-

Glad to see you weigh in, finally!

For someone to communcate a biconditional statement in plain English, really the only way to do it is by using "if and only if." Why didn't Dusman do that? For that matter, why didn't you use that? Without the words, "if and only if," it's not a clear biconditional, and is very much a fallacy.

My next question is: how do you prove a biconditional? Is it necessary to prove both conditionals separately?

 
At 2/19/2006 9:28 PM, Blogger Paul Manata declaimed...

Moore,. I know that. But you need to learn how to translate arguments. i didn;t read Dustin's post and so I don;t know what other info he gave. That's why I said that "DEPENDING ON WHAT HE SAID" you might have translated it that way. Sheesh! Anyway, my point was that EVEN IF he had said iff, then the Y still goes in the CONSEQUENT POSITION.

You maid the Y go in the ANTECEDENT. You failed to translate it properly. Now, take your lumps like a man and admit you were wrong.

Oh, and don't try and act like you knew about bioconditionals. I know you just looked it up. Your constant ignorance on this subject proves you have no clue what you're talking about.

The way you hold to your faith is always funny to me.

 
At 2/19/2006 9:56 PM, Blogger Paul Manata declaimed...

http://triablogue.blogspot.com/2006/02/no-one-responded-to-my-horrible_19.html

 
At 2/20/2006 8:11 AM, Blogger Zachary Moore declaimed...

Aha. So this post was silly and ridiculous enough that you just had to post on tribalogue about it? You're so transparent, buddy.

But you still haven't clarified things for me. Is this, in fact, the formal presuppositional argument? That's the question that I've been asking since the beginning. If it's a biconditional, are you able to prove both conditionals, and how do you do so?

I'm trying to learn here, Paul. So far, you're just interested in boastful talk.

 
At 2/20/2006 10:25 AM, Blogger Paul Manata declaimed...

No you're not, Zach.

You said, "No presuppositionalists want to weigh in on this before it slips off the front page? Well, I guess I had it right, then."

Your false piety isn't working on me.

Bioconditionals have *nothing* to do with the point I'm making. It's just another one of your attempts to shift the focus off the real issue.

So, try and get this: The real issue is that you translated the "for-has" premise the wrong way. Your critique was that it commits the fallacy of affirming the consequent. That was your ENTIRE critique, i.e., that it affirms the consequent. But if you had translated it correctly, Zach, then you couldn't of made your critique. You were wrong about Dustin's argument. It does not affirm the consequent. Just admit it.

Also, to ask how I can prove anything is beyond the scope of your post. I answerd *your* post. Don't act like not showing *how* to prove something is a defect in what I wrote. I answerd *your critique* of Dustin.

Anyway, you prove a TA by retortion. And, yes, modus ponens (how dustin had it) is basically the form all TAs take (Christian and non-Christian).

 
At 2/20/2006 4:03 PM, Blogger Zachary Moore declaimed...

"You said, "No presuppositionalists want to weigh in on this before it slips off the front page? Well, I guess I had it right, then.""

Yeah, pretty funny. I wondered if that would get your goat. I guess I was right.

"Bioconditionals have *nothing* to do with the point I'm making. It's just another one of your attempts to shift the focus off the real issue."

Not at all. You said that Dustin's argument was correctly translated as a biconditional. Well, fine. That's what I'm trying to get to the root of- what the presuppositional argument is. Of course, I'd like to see the logic book that says that "for-has" conditionals are really biconditionals. From what I've seen, you really have to specify "if and only if" to be clear. Dustin didn't do that, and you didn't chide him for not doing so, so I'm still wondering- did he really intend for it to be a biconditional? I mean, really. Sure, making it a biconditional escapes the fallacious form, but can it really be rewritten as I quoted it? Or are you just reaching for some way to escape the fallacy?

"So, try and get this: The real issue is that you translated the "for-has" premise the wrong way."

Maybe so. But I'd like for you to show me the logic book that tells me that a proper conditional statement is writen "for-has." I always understood "If-then" to be the proper English form.

"Anyway, you prove a TA by retortion."

Well, okay. But here's what I pointed out before, nobody is going to retort logic, because obviously that's self-defeating. The issue whether you can argue that the existence of God is necessary for the existence of logic. So now we're back to the beginning. If God, then logic, right? But then you can't put forth logic, because we're back to a fallacy.

Can a guy get a straight answer here?

 
At 2/20/2006 5:18 PM, Blogger groundfighter76 declaimed...

Zach said, "I'm trying to learn here, Paul."

For some reason, I find this particularly difficult to believe.

 
At 2/21/2006 10:53 AM, Blogger Zachary Moore declaimed...

Groundfighter-

Did you even read my post all the way to the bottom?

"Of course, this is just based on the postings of two individuals who claim presuppositional apologetic strategies. They may be incorrect in their formulation of the presuppositional argument, in which case I look forward to seeing the real McCoy. Or maybe there are some subtleties to the argument that I’ve missed. Either way, I’m eagerly anticipating edification."

 
At 2/22/2006 1:28 PM, Blogger groundfighter76 declaimed...

Yes I did read it Zach, but so what? Am I just supposed to believe you because you said it?

good one, zach...

 
At 2/22/2006 6:41 PM, Blogger Zachary Moore declaimed...

"Am I just supposed to believe you because you said it?"

Well, you believe in the truth of the Bible because it says so. I mean, why be stingy with your gullibility?

 

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