Does inductive reasoning lead to knowledge?
in [Logic]
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From: M Purcell on 13 Dec 2009 23:32 On Dec 13, 4:56 pm, dorayme <doraymeRidT...(a)optusnet.com.au> wrote: > In article <daniel_t-D773AE.18584313122...(a)earthlink.us.supernews.com>, > "Daniel T." <danie...(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. Yes, a proposition must be imagined first. And since there may be an unimagined proposition that contradicts the known, I suppose the certainty of an assumption is limited by our imagination.
From: John Stafford on 14 Dec 2009 01:53 In article <doraymeRidThis-75E190.15203014122009(a)news.albasani.net>, dorayme <doraymeRidThis(a)optusnet.com.au> wrote: > 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? > > [...]. I screwed up and addressed deductive reasoning. Sorry for that!
From: Patricia Aldoraz on 14 Dec 2009 02:26 On Dec 14, 3:32 pm, M Purcell <sacsca...(a)aol.com> wrote: > On Dec 13, 4:56 pm, dorayme <doraymeRidT...(a)optusnet.com.au> wrote: > > > > > In article <daniel_t-D773AE.18584313122...(a)earthlink.us.supernews.com>, > > "Daniel T." <danie...(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. > > Yes, a proposition must be imagined first. And since there may be an > unimagined proposition that contradicts the known, I suppose the > certainty of an assumption is limited by our imagination. I think there is a misunderstanding. The point is not about how a proposition seems but rather that how some things seem to humans has traditionally been argued to be incorrigible, not able to be doubted, not able to be imagined wrong. It has been argued that my seeming to see a red patch before my eyes is something that needs no argument to establish, there is no evidence beyond the act of it seeming so to me that could count as being evidence for it. That rules out inductive reasoning being the justification. And there is surely no deductive argument that brings us to the proposition. If such statements about my experience are neither deductively arrived at nor inductively arived at, it does not augur well for the idea that there is some circularity in a deductive argument that contains such premises.
From: M Purcell on 14 Dec 2009 08:58 On Dec 13, 11:26 pm, Patricia Aldoraz <patricia.aldo...(a)gmail.com> wrote: > On Dec 14, 3:32 pm, M Purcell <sacsca...(a)aol.com> wrote: > > > > > > > On Dec 13, 4:56 pm, dorayme <doraymeRidT...(a)optusnet.com.au> wrote: > > > > In article <daniel_t-D773AE.18584313122...(a)earthlink.us.supernews.com>, > > > "Daniel T." <danie...(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. > > > Yes, a proposition must be imagined first. And since there may be an > > unimagined proposition that contradicts the known, I suppose the > > certainty of an assumption is limited by our imagination. > > I think there is a misunderstanding. The point is not about how a > proposition seems but rather that how some things seem to humans has > traditionally been argued to be incorrigible, not able to be doubted, > not able to be imagined wrong. The misunderstanding is yours. > It has been argued that my seeming to see a red patch before my eyes > is something that needs no argument to establish, there is no evidence > beyond the act of it seeming so to me that could count as being > evidence for it. That rules out inductive reasoning being the > justification. And there is surely no deductive argument that brings > us to the proposition. The fact that you are ignorant of other evidence does not preclude it's existance. > If such statements about my experience are neither deductively arrived > at nor inductively arived at, it does not augur well for the idea that > there is some circularity in a deductive argument that contains such > premises. Justifying your experience because it is your experience is a circular argument.
From: PD on 14 Dec 2009 11:38
On Dec 12, 8:01 pm, Immortalista <extro...(a)hotmail.com> wrote: > What is the justification for either: > > 1. generalising about the properties of a class of objects based on > some number of observations of particular instances of that class (for > example, the inference that "all swans we have seen are white, and > therefore all swans are white," before the discovery of black swans) > or > > 2. presupposing that a sequence of events in the future will occur as > it always has in the past (for example, that the laws of physics will > hold as they have always been observed to hold). > > http://en.wikipedia.org/wiki/Problem_of_induction > > ------------------------------------------ > > Two views of Deduction & Induction: > > View 1: conclusion; > Deduction = infers particular from general truths > Induction = infers general from particular truths > > View 2: conclusion; > Deduction = follows with absolute necessity > Induction = follows with some degree of probability > > Deduction and Induction From > Introduction to Logic Irving M. Copihttp://www.amazon.com/exec/obidos/tg/detail/-/0130749214/ The rationale for inductive reasoning is that it works expeditiously in matters of science. The reason why it works is because of the options of controlled experiment and abundant observational opportunity. This is in fact the crucial step, as the inference itself as an internal mental process proves little. This is the mistake that many hobbyists make, judging both theories and the methodology used to produce them on the basis of the purely *mental* process. On that basis, then deduction is more sound than induction. This basis is attractive to hobbyists because it requires no resources other than a brain. However, science involves observation and measurement, and this additional component is what makes the difference, even though that becomes prohibitive to many hobbyists. |