[B5JMS] Message to JMS about ASM #511

[b5jms at cs.columbia.edu]

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From: Adam Cadre <see-website-for-address at adamcadre.ac>
Lines: 44
Date: Sun, 29 Aug 2004 09:31:59 GMT

Scott Dubin wrote:
 > "Comics worth reading" sounds to me like "Here's a list of comics
 > worth reading."
 >
 > You rephrased it to mean "Here's a list of the only only comics that
 > are worth reading.  All other comics suck."

This is a logical error known as assuming the inverse.  While the
contrapositive of a true statement is always true, the inverse is
not necessarily so.

Example 1:
"If you're in Times Square, you're in New York."

The contrapositive of this statement flips and negates the two halves,
leaving us with "If you're not in New York, you're not in Times Square."
Makes sense.

The inverse, however, negates the two halves without flipping them.
This gives us "If you're not in Times Square, you're not in New York."
That's certainly not a true statement.

(The converse flips the two halves, giving us "If you're in New York,
you're in Times Square."  This isn't necessarily true either.)

(One of my pet peeves is when people begin a statement with
"Conversely..." and then say something that isn't the converse of
anything they've previously said.)

Example 2:
"If a comic is on this list, it's worth reading."

Contrapositive: "If a comic isn't worth reading, it's not on this list."
If Johanna titles her page Comics Worth Reading, she should obey this
rule.

Inverse: "If a comic isn't on this list, it's not worth reading."
Johanna does NOT have to obey this rule.  The inverse of a statement
does NOT follow logically from that statement.  We must judge its
truth or falsehood independently of the original statement.

   -----
  Adam Cadre, Holyoke, MA
  http://adamcadre.ac

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Lines: 19
From: jmsatb5 at aol.com (Jms at B5)
Date: 29 Aug 2004 22:01:38 GMT

>Inverse: "If a comic isn't on this list, it's not worth reading."
>Johanna does NOT have to obey this rule.  The inverse of a statement
>does NOT follow logically from that statement.  We must judge its
>truth or falsehood independently of the original statement.

Except of course that's not what I said.  I said that the implication is that
if a comic that's reviewed doesn't measure up, it's not worth reading...never
got into the question of what wasn't reviewed (and actually made the point of
saying it excluded books not yet read).

 jms

(jmsatb5 at aol.com)
(all message content (c) 2004 by synthetic worlds, ltd., 
permission to reprint specifically denied to SFX Magazine 
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