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《(普特南) Putnam - 1971 - 'Philosophy of Logic'》由会员上传分享，免费在线阅读，更多相关内容在学术论文-天天文库。
1、PhilosophyofLogic405(3)pandnot-p.Andstillanotherprincipleisthevalidityofthis:(4)pornot-9.Letusnowlookattheseprinciplesonebyone.Inference(1)istraditionallyPhilosophyofLogicstatedtobevalidforalltmS,M,P.Butwhatisaterm?Textsofcontemporarylogicusuallysaythat(1)isvalidnomatterwhatclassesmayb
2、eassignedtothelettersS,MandPastheirextensions.Inference(1)thenbecomesjustawayofsayingthatifaclassSisasubclassofaclassM,andMisinturnasubclassofaHilaryPutnamclassP,thenSisasubclassofP.Inshort,(1)onitsmoderninterpretationjustexpressesthetransitivityoftherelation'subclassofI.Thisisafarcryf
3、romwhat1WhatLogicIstraditionallogiciansthoughttheyweredoingwhentheytalkedaboutLawsofThoughtand'terms'.HerewehaveoneoftheconfusingthingsaboutthescienceLetusstartbyaskingwhatlogicis,andthentrytoseewhythereshouldbeaoflogic:thatevenwhereaprinciplemayseemtohaveundergonenochangeinthephilosop
4、hicalproblemaboutlogic.Wemighttrytofindoutwhatlogicisbycourseofthecenturies-e.g.westillwrite:examiningvariousdefinitionsof'logic',butthiswouldbeabadidea.Thevariousextantdefinitionsof'logic'managetocombinecircularitywithinexactnessinoneAllSareMwayoranother.Insteadletuslookatlogicitself.
5、AllA4arePIfwelookatlogicitself,wefirstnoticethatlogic,likeeveryotherscience,(therefore)AllSarePundergoeschanges-sometimesrapidchanges.Indifferentcenturieslogicianshavehadverydifferentideasconcerningthescopeoftheirsubject,themethods-theinterpretationofthe'unchanging'truthhas,infact,chan
6、gedconsiderably.propertoit,etc.Todaythescopeoflogicisdefinedmuchmorebroadlythanitwhatisworse,thereisstillsomecontroversyaboutwhatthe'correct'interpreta-everwasinthepast,sothatlogicassomelogiciansconceiveit,comestoincludealltionis.ofpuremathematics.Also,themethodsusedinlogicalresearchto
7、dayarealmostPrinciple(2)isanotherexampleofa~rinciplewhosecorrectinterpretationisexclusivelymathematicalones.However,certainaspectsoflogicseemtoundergoindispute.Theinterpretationfavouredbymostlogicians(includingthelittlechange.Logicalresults,onceestablished,seemtoremainforeveraccepted
