Jerry wrote: The swan example:
Rule: All swans are white Case: Jimmy is a swan Result: Jimmy is white. Except, all swans are not white. Some are black. But people thought swans were only white long ago...or so they say. Also, given our awareness of genetics, there was always the possibility that swans could have been black...blue, even. [, , ,] So, is the deductive swan example necessary reasoning? Is it correct? Is the intention of deductive reasoning and syllogisms in general to promote correct reasoning or necessary reasoning? The form of the syllogism is correct. For deductive reasoning the conclusion will necessarily be true if the rule is true. In the swan example it is not true that all swans are white, so the conclusion is not necessarily correct, although its form most certainly is. This is pretty basic logic. Best, Gary R [image: Gary Richmond] *Gary Richmond* *Philosophy and Critical Thinking* *Communication Studies* *LaGuardia College of the City University of New York* *C 745* *718 482-5690* On Wed, Apr 27, 2016 at 5:45 PM, Gary Richmond <[email protected]> wrote: > List, > > Not to be taken too seriously--as this was just a bit of play which > occupied me for an hour or so today-- but based on the bean example, here's > how I see the three inference patterns and their paths (vectors) through > the 3 categories. > > *Inference patterns and categoriality:* > 1ns, Result (for deduction only) == 'Character' (for abduction/induction) > |> 3ns, Rule > 2ns, Case > > Middle term: That which is the middle term in deduction is put in *bold *in > all 3 patterns > Vectorial order: In each case start at * and conclude at *** > > *Deduction* (vector of involution): > ***3rd, 1ns: *conclusion*-It is NECESSARY that Jesus die. > |> *1st, 3ns: All *men* die, > **2nd, 2ns: Jesus is a *man*; > > *Abduction* (vector of representation): > **2nd, 1ns: Jesus died; > |> *1st, 3ns: I make the supposition that all *men* die, > ***3rd, 2ns: *conclusion*-It is POSSIBLE that Jesus was but a *man*. > > *Induction* (vector of determination): > **2nd, 1ns: Jesus dies; > |> ***3rd, 3ns: *conclusion*-It is PROBABLE that all *men* die. > *1st, 2ns: Jesus is a *man, * > > Well, again, one doesn't want to make too much of this except to note that > both deduction and abduction begin with a rule (in abduction, a mere > 'supposition'), while induction concludes with a rule (which has some > probability). > > Best, > > Gary R >
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