Does inductive reasoning lead to knowledge?
in [Logic]
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From: dorayme on 13 Dec 2009 19:56 In article <daniel_t-D773AE.18584313122009(a)earthlink.us.supernews.com>, "Daniel T." <daniel_t(a)earthlink.net> wrote: > My basic point is that for all sound deductive arguments, there must be > a set of true premises. These premises are eather deductivly true (which > leads to a circle,) true by definition (as in your example,) or > inductivly true. I doubt if a reasonable belief in a proposition has to fall into one of these three categories. It can be reasonable to believe something because there is nothing else one can think of that explains as much. This is not obviously something that can be squeezed into these straight jackets. Not only is it not the case that it looks forced to think of explanation as induction from cases but there is the question of statements which are not "true by definition" (using your terms) but which are impossible to deny, such as first person statements about how things *seem* to the person. -- dorayme
From: dorayme on 13 Dec 2009 20:03 In article <daniel_t-333938.19103413122009(a)earthlink.us.supernews.com>, "Daniel T." <daniel_t(a)earthlink.net> wrote: > dorayme <doraymeRidThis(a)optusnet.com.au> wrote: > > "Daniel T." <daniel_t(a)earthlink.net> wrote: > > > > > .... all deductive arguments rely on either arbitrary definitions > > > or inductive arguments. > > > > > > > How so? > > Every sound deductive argument requires true premises. Soundness in the sense of validity of argument has nothing to do with the truth per se of the premises or the conclusions. This sort of logical goodness is only about the relationship between the truth of either. Naturally an argument often is the worse for not having true premises in any actual practical use. > These premises > must be proven true through either deductive or inductive arguments, or > by arbitrary definitions. > No, this is incorrect or at least is not obvious. I replied in another post on this matter. -- dorayme
From: John Stafford on 13 Dec 2009 20:39 In article <doraymeRidThis-09A13A.11563314122009(a)news.albasani.net>, dorayme <doraymeRidThis(a)optusnet.com.au> wrote: > In article <daniel_t-D773AE.18584313122009(a)earthlink.us.supernews.com>, > "Daniel T." <daniel_t(a)earthlink.net> wrote: > > > My basic point is that for all sound deductive arguments, there must be > > a set of true premises. These premises are eather deductivly true (which > > leads to a circle,) true by definition (as in your example,) or > > inductivly true. > > I doubt if a reasonable belief in a proposition has to fall into one of > these three categories. > > It can be reasonable to believe something because there is nothing else > one can think of that explains as much. This is not obviously something > that can be squeezed into these straight jackets. > > Not only is it not the case that it looks forced to think of explanation > as induction from cases but there is the question of statements which > are not "true by definition" (using your terms) but which are impossible > to deny, such as first person statements about how things *seem* to the > person. In deductive reasoning, arguments that depend upon how things "seem" is immediately weak so the argument is not sound. Discard it. That's how it works.
From: Patricia Aldoraz on 13 Dec 2009 22:58 On Dec 14, 12:39 pm, John Stafford <n...(a)droffats.ten> wrote: > > In deductive reasoning, arguments that depend upon how things "seem" is > immediately weak so the argument is not sound. Discard it. That's how it > works. That is how *what* works exactly?
From: dorayme on 13 Dec 2009 23:20
In article <76ceb3ee-0a86-42c2-a6fb-2332712fbe20(a)z3g2000prd.googlegroups.com>, Patricia Aldoraz <patricia.aldoraz(a)gmail.com> wrote: > On Dec 14, 12:39 pm, John Stafford <n...(a)droffats.ten> wrote: > > > > In deductive reasoning, arguments that depend upon how things "seem" is > > immediately weak so the argument is not sound. Discard it. That's how it > > works. > > That is how *what* works exactly? There are various types of weaknesses in arguments, one being the premises do not support the conclusion, the other being the conclusion is too obviously contained in the premises, another would be the premises are false. These things need to be distinguished and some sort of context mentioned otherwise sweeping generalizations look like false knee jerk reactions to what was actually said. Arguments that depend on how things seem are not immediately weak in the sense that they *must* have false premises. They are not necessarily weak in the sense that they *must* lack the entailment relationship. A patient tells his doctor: "I seem to see a fog when I first open my eyes in the mornings. "There is never any fog at this time of the year. "Therefore, there is something wrong with me" There are even trivial but perfectly valid ones like: "I seem to always think Mr. X is a bachelor! Therefore I always seem to think Mr. X is an unmarried man." -- dorayme |