Max,
Thanks for the info. After class I found an online Britannica
article which explains the Latin derivation. Modus ponens
literally means "method of affirming" and modus tollens means
"method of denying."
Tim
>Tim:
>
>In a nutshell:
>According to Ray (2000), modus ponens involves confirmatory reasoning:
>If p, then q.
>P.
>Therefore, q.
>
>Modus Tollens involves disconfirmatory reasoning:
>If p, then q.
>Not q.
>Therefore, not p.
>
>I don't know the etiology of the terms, but you can check out:
>http://www.bu.edu/wcp/Papers/Logi/LogiDagl.htm
>
>which states:
>
>According to the Stoic logicians, the first kind of indemonstrable
>statements is as follows: "If the first, then the second; but the first;
>therefore the second." We call this basic argument form as modus ponendo
>ponens, in abbreviation modus ponens, the mood that by affirming affirms.
>The second kind of indemonstrable statements of the Stoics is: "If the
>first, then the second; but the second is not; therefore the first is
>not." This basic argument form is called as modus tollendo tollens, in
>abbreviation modus tollens, the mood that by denying denies, nowadays.(2)
>
>
>-Max
>
>
>On Fri, 26 Jan 2001, Tim Gaines wrote:
>
>> I'm putting TIPS to the test this morning. In 30 minutes I'll
>> be talking to my Research Methods class about the logic of
>> testing theories, and one point I want to make is that neither
>> of the two logically valid modes of syllogistic reasoning
>> (modus ponens and modus tollens) permits confirmation of the
>> antecedent (the theory). It would be nice to be able to
>> provide the etiology of the terms, but I have loaned my copy
>> of Wason and Johnson-Laird to a student, and I can't seem to
>> find the terms in other references I have. Anyone know these
>> terms?
>>
>> Thanks,
>>
> > Tim
> > --
>
> >
>
>Maxwell Gwynn, PhD [EMAIL PROTECTED]
>Department of Psychology (519) 884-0710 ext 3854
>Wilfrid Laurier University
>Waterloo, Ontario N2L 3C5 Canada
