Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!sri-unix!chips2.sri.com!ellis
From: ellis@chips2.sri.com (Michael Ellis)
Newsgroups: comp.ai
Subject: Re: abduction vs. induction
Keywords: induction
Message-ID: <32132@sri-unix.SRI.COM>
Date: 25 May 89 14:57:36 GMT
References: <1480@crin.crin.fr> <526@thor.wright.EDU> <287@kubix.UUCP>
Sender: news@unix.SRI.COM
Reply-To: ellis@chips2.sri.com.UUCP (Michael Ellis)
Organization: SRI International
Lines: 38

> Peter Flach >> Venu Dasigi

>Peirce's beautiful characterisation of deduction, induction and abduction:

    Peirce's thought is indeed beautiful.

>>Starting with

>>1. A --> B (if a sample is from this bag, the sample is white.)
>>2. A (this sample s is from this bag.)
>>3. B (the sample s is white.)

>>Deduction amounts to concluding 3 from 1 and 2.
>>Induction amounts to concluding 1 from 2 and 3.
>>Abduction amounts to concluding 2 from 1 and 3.

>The formulation of induction given here, brings into mind a problem that
>has been bothering me for some time. Given premises A and B, why should
>I prefer the inductive conclusion A --> B over B --> A (any white sample
>is from this bag)?

    That's a good point, but it doesn't seem to show up in Peirce's
    original formulation, which follows:

				DEDUCTION:	
		Rule-	All the beans from this bag are white
		Case-	These beans are from this bag
      Therefore	Result-	These beans are white
				INDUCTION:	
		Case-	These beans are from this bag
		Result-	These beans are white
      Therefore	Rule-	All the beans from this bag are white
				ABDUCTION:	
		Rule-	All the beans from this bag are white
		Result-	These beans are white
      Therefore Case-	These beans are from this bag

-michael