From: ksand@apple.com (Kent Sandvik )
Newsgroups: talk.religion.misc
Subject: Re: Criticism: "There's no logic in Christianity"
Date: 6 Jan 93 19:26:54 GMT
Followup-To: talk.religion.misc
Organization: (Evil Eye Creature from Mars, Inc.)

In article <1993Jan4.202908.2644@csrd.uiuc.edu>, skinner@sp94.csrd.uiuc.edu
(Gregg Skinner) wrote:
> I am at a loss to understand what either of Mr. Sandvik or Mr. Sarver
> means when he uses the term, "valid argument".  Each has objected
> strongly to the standard meaning: If the premise is true, then the
> conclusion must be true.  In order to help clarify, I ask them to
> define "valid logical argument" and answer the following questions.
 
> Is the following a valid logical argument?  If not, please explain.
> 
>      Premise:
> 	  1. A is B.
> 	  2. C is ~A.  (where ~ represents negation)
> 	  3. D is true.
> 	  4. if D, then E implies ~C.
> 	  5. F implies E.

I agree that we all have agreed upon the logical a priory rules, so 
the rules are valid. However, let me know what you mean with A, B and 
C and then we could shake out the conclusions from opinions. There's a
gap between the formal logical definitions humans have agreed upon,
and the 'supposedly' logical constructs where the rules are used.

>      Propositions:
> 	  a. C is ~B.  (From 1 and 2)
> 	  b. if D, then E implies B. (a and 4)
> 	  c. E implies B. (b and 3)
> 
>      Conclusion: F implies B. (c and 5)

See answer above.
 
> Is the following (taken from a logic text) a valid logical argument?
> If not, and if the reason differs from the one given above, please
> explain.  (The texts says it's valid.)
> 
>      Premise:
>           1. p
> 	  2. p implies q
>           3. ~q or r
> 
>      Conclusion: r

See answer above.

> Mr. Sandvik asks me whether the following is logical.
> 
>      Let's give an example, now I establish a premiss called
>      SchlackerDunkGestalt -- and a couple more, and just to honour the
>      tradition to use weird foreign/german names, I do the same:
> 
>      SchlackerDunkGestalt is the ultimate PrippsMacht of
>      DunkerLangerung. If DunkerLangerung has a NichtVerlangen, then
>      PrippsMacht will unterlangetize SchlackerkDunkGestalt!
> 
> For brevity, I substitute A for SchlackerDunkGestalt, B for
> PrippsMacht C for DunkerLangerung, and D for NichtVerlangen.  The
> argument takes the form:
> 
>      1. A
>      2. A is the ultimate B of C.
>      3. If C has a D, then B will unterlangetize A.
> 
> Mr. Sandvik says this is a "fully logical construct", so I must assume
> there is a premise and a conclusion.  As it is not specified, I will
> assume the conclusion appears last.  The argument is then as follows.
> 
>      Given "A" and "A is the ultimate B of C", 
>      it follows that "if C has a D, then B will unterlangetize A."
> 
> The premise makes no statements about C or D; however "if C has a D"
> might be trivially true, so we must continue.  "B will unterlangetize
> A."  There is nothing in the premise that indicates this is the case,
> regardless to whether or not C has a D.  The argument as it stands is
> not logically valid, for the truth of the premise does not imply the
> truth of the conclusion.

Well, I think I made my point. You didn't know about the premises because
there was no *agreement* on these, neither did you know about the logical
outcome because you *assumed* the assertions. Moreover, if I tell you
that 'unterlangetize' is mapped in my assertion to 'negate' or something
similar, then B will negate A if C has D. Or map it to something else,
if we agree that 'ultimate' stands for, if 'ultimate' is the last
negative number, and where C is a - sign, so:

the number A is the last negative number B in the set of C.
If C has a '-' operator that operates on the set C, then the last negative
number B will negate A (itself).

Or we could make many more definitions based on our interpretations
of the premises. I could make one about Christianity as well, if you like!

> Mr. Sandvik may object (he has in the past) that it makes no sense to
> apply the tools of logic to such an abstract statement.  I disagree.
> This is a skill learned in elementary logic courses.  I cite an
> exercise from an elementary logic text:

Did they tell you in logic class about a priori agreements about 
universals, such as logical tools?

>      Analyze these arguments for logical validity.
>      ...
>      7. All fields are rings.  Some rings are integral domains.  Some
>      integral domains are not fields.  Therefore some rings are not
>      fields.

Note the difference once again, we agree that a ring and a field is,
so we don't have problems ending up with figuring out this this makes
sense or not. There's one case however, where 'ring' might be a
ring on a finger, or a ring in water, and where field is either a
gravitational
field, or a field between the forests, so we still have the need to 
fully qualify the assertions before we could attack the actual statement.

I hope this once again clarified the situation concerning religion and 
premises. Logic works pretty well if we agree on the premises, if we don't
we are dealing with metaphysics that may or may not be true/false, 
depending on your own personal bias.

Kent
-------------------
Kent Sandvik (UUCP: ....!apple!ksand; INTERNET: ksand@apple.com)
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Newsgroups: talk.religion.misc