🚀 go-pugleaf

ksand@apple.com (Kent Sandvik ) writes:

>I ended up in trouble on one of the religious groups due to demonstration
>of logical validity, and where I personally was unable to quantify and
>draw a conclusion if premises such as sin, God and similar constructs
>ended up in a true or a false statement. 

Mr. Sandvik's trouble came from making the easily falsified claim
"There's nothing logical about Christianity."  When he rejected a
simple counter-example, it eventually became clear he claim relies on
a non-standard definition of logic:

     My personal interpretation of a logically valid argument is one
     where the outcome is clearly a known statement.

For Mr. Sandvik to find logic in an argument, the premises and the
conclusion must be true.  (If they are unverifiable, as in the case of
Euclidean geometry, he will admit to logic in an argument if there
some sort of "universal agreement".)

This notion can be contrasted with a passage from "Logic: A Modern
Introduction to Deductive Reasoning" by D.B. Terrell:

     An argument can be valid even though its premises and its
     conclusion are all false or the premises false (or one or more
     premises false) and the conclusion true.  As long as we must say
     that if the premises were true, the conclusion would have to be
     true as well, validity is not affected by the actual truth or
     falsity of the argument's component parts.

     From what has just been said about validity, it is clear
     that the mere validity of an argument does not insure
     the truth of its conclusion....



                                  Gregg Skinner