Jerry, You're attempting to discuss apples and oranges here. Here are the basics as given in the syllabus for a first course in logic:
*Introduction to LogicTruth, Validity, and Soundness* I. Truth, Validity, and Soundness: probably the three most important concepts of the course. A. First, let us briefly characterize these concepts. 1*. truth*: a property of statements, *i.e*., that they are the case. 2. *validity*: a property of arguments, *i.e*., that they have a good structure. (The premisses and conclusion are so related that it is absolutely impossible for the premisses to be true unless the conclusion is true also.) 3. *soundness*: a property of both arguments and the statements in them, *i.e*., the argument is valid and all the statement are true. *Sound Argument*: (1) valid, (2) true premisses (obviously the conclusion is true as well by the definition of validity). B. The fact that a deductive argument is valid cannot, in itself, assure us that any of the statements in the argument are true; this fact only tells us that the conclusion must be true* if *the premisses are true. 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 Thu, Apr 28, 2016 at 3:00 PM, Jerry Rhee <[email protected]> wrote: > Thanks Gary, > > What about my last question? Would you say there's an intention to > deduction or using syllogisms or is that so ambiguous we leave it alone? > > I guess the reason I ask is because if everyone agrees that all swans are > white, then there's no problem...but it's often the case that arguments > happen because they don't agree on the premise that all swans are white and > syllogisms are of little help. > > Best, > J > > > > On Thu, Apr 28, 2016 at 1:54 PM, Gary Richmond <[email protected]> > wrote: > >> 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 <718%20482-5690>* >> >> 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 >>> >> >> >> >> ----------------------------- >> PEIRCE-L subscribers: Click on "Reply List" or "Reply All" to REPLY ON >> PEIRCE-L to this message. PEIRCE-L posts should go to >> [email protected] . To UNSUBSCRIBE, send a message not to PEIRCE-L >> but to [email protected] with the line "UNSubscribe PEIRCE-L" in the >> BODY of the message. More at >> http://www.cspeirce.com/peirce-l/peirce-l.htm . >> >> >> >> >> >> >
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