Does inductive reasoning lead to knowledge?
in [Logic]
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From: Frederick Williams on 13 Dec 2009 10:34 Immortalista wrote: > Induction = follows with some degree of probability Try proving that! (Or read Hume.) -- Pigeons were widely suspected of secret intercourse with the enemy; counter-measures included the use of British birds of prey to intercept suspicious pigeons in mid-air. Christopher Andrew, 'Defence of the Realm', Allen Lane
From: Daniel T. on 13 Dec 2009 15:17 Immortalista <extropy1(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. Copi > http://www.amazon.com/exec/obidos/tg/detail/-/0130749214/ The problem is that all deductive arguments rely on either arbitrary definitions or inductive arguments. Everything we know about reality is ultimately inductive. So what's your point?
From: dorayme on 13 Dec 2009 17:02 In article <daniel_t-283CEC.15173013122009(a)earthlink.us.supernews.com>, "Daniel T." <daniel_t(a)earthlink.net> wrote: > > .... all deductive arguments rely on either arbitrary > definitions or inductive arguments. > How so? > Everything we know about reality is ultimately inductive. This is a big claim! Got any argument for it? -- dorayme
From: Daniel T. on 13 Dec 2009 18:58 Frank Eskesen wrote (to me via email): > Daniel T. wrote: > > Immortalista <extropy1(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. > > > Copi http://www.amazon.com/exec/obidos/tg/detail/-/0130749214/ > > > > The problem is that all deductive arguments rely on either > > arbitrary definitions or inductive arguments. > > > > Everything we know about reality is ultimately inductive. So > > what's your point? > > I'm not sure whether, ultimately, I'm disagreeing with you, but some > things that we know about reality might be relational. >� > For example, we know about lines as sums of points, areas as sums of > lines, and volumes as sums of areas. The list goes on, backwards and > forwards. Physics is just chock full of relational equations. These > equations are things we say we (conditionally) know. We *define* lines as sums of points and areas as sums of lines and volumes as sums of areas. I don't think you are disagreing with me. You seem to be simply bringing up a particular case. 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.
From: Daniel T. on 13 Dec 2009 19:10
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. These premises must be proven true through either deductive or inductive arguments, or by arbitrary definitions. Note that the above statement is circular in regards to deductive arguments and only stops at premises that are true either by definition or deductively. Therefore, all deductive arguments ultimately rely on either arbitrary definitions or inductive arguments. I can see where you might want to quibble with me about the use of the word "arbitrary" but the point here is that the definitions in question cannot be justified through either deductive or inductive arguments, so consider that to be the definition of "arbitrary" for this special case. (The above deductive argument itself ultimately relies on definitions.) |