From nicholas@uci.edu Mon Aug 27 00:17:35 2001 Return-Path: X-Sender: nicholas@uci.edu X-Apparently-To: lojban@yahoogroups.com Received: (EGP: mail-7_3_2); 27 Aug 2001 07:17:35 -0000 Received: (qmail 54757 invoked from network); 27 Aug 2001 07:17:34 -0000 Received: from unknown (10.1.10.27) by m8.onelist.org with QMQP; 27 Aug 2001 07:17:34 -0000 Received: from unknown (HELO e4e.oac.uci.edu) (128.200.222.10) by mta2 with SMTP; 27 Aug 2001 07:17:34 -0000 Received: from [128.195.187.106] (dialin53b-09.ppp.uci.edu [128.195.186.149]) by e4e.oac.uci.edu (8.9.3/8.9.3) with ESMTP id AAA27328 for ; Mon, 27 Aug 2001 00:15:59 -0700 (PDT) X-Sender: nicholas@e4e.oac.uci.edu Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Mon, 27 Aug 2001 00:20:08 -0700 To: lojban@yahoogroups.com Subject: Re: Induction From: Nick Nicholas cu'u la xod. > What is the difference between abduction and deduction? Deduction: I have a Case, and a Rule, and I infer a Result Case: Socrates is human Rule: All humans are mortal Result: Therefore, Socrates is mortal Induction: I have a Case and a Result, and I infer a Rule Case: Socrates is human Result: Socrates is mortal Rule: Therefore, All humans are mortal (If you're a good scientist, you haven't used just one Case-Result pair!) Abduction: I have a Result and a Rule, and I infer a Case Rule: All humans are mortal Result: Socrates is mortal Case: Therefore, Socrates is human As is well known, abduction is logically just silly (the classic counterexample is, Socrates is a fruit fly.) But human are forced to do abduction all the time. For instance, language parsing: you're working backwards from the Result (the sentence you heard) and the Rule (grammar) to obtain the Case (what was meant). Unlike deduction, abduction is indeed logically fallible; that's why misunderstanding sentences is possible. induction is sucta. deduction and abduction are both tolsucta. deduction is the logical reverse of abduction. Nick Nicholas, TLG, UCI, USA. nicholas@uci.edu www.opoudjis.net "Most Byzantine historians felt they knew enough to use the optatives correctly; some of them were right." --- Harry Turtledove.