ItmayperhapsbeexpectedthatIshouldbeginalectureontherelationsbetweenthoughtandlanguagewithsomedefinitionofboththesethings；butthought，asSirWilliamGrovesaidofmotion，isaphenomenon\"soobvioustosimpleapprehension，thattodefineitwouldmakeitmoreobscure。\"{17}Definitionsareusefulwherethingsarenewtous，buttheyaresuperfluousaboutthosethatarealreadyfamiliar，andmischievous，sofarastheyarepossibleatall，inrespectofallthosethingsthatentersoprofoundlyandintimatelyintoourbeingthatinthemwemusteitherliveorbearnolife。Tovivisectthemorevitalprocessesofthoughtistosuspend，ifnottodestroythem；forthoughtcanthinkabouteverythingmorehealthilyandeasilythanaboutitself。Itislikeitsinstrumentthebrain，whichknowsnothingofanyinjuriesinflicteduponitself。Asregardswhatisnewtous，adefinitionwillsometimesdiluteadifficulty，andhelpustoswallowthatwhichmightchokeusundiluted；buttodefinewhenwehaveoncewellswallowedistounsettle，ratherthansettle，ourdigestion。
Definitions，again，arelikestepscutinasteepslopeofice，orshellsthrownontoagreasypavement；theygiveusfoothold，andenableustoadvance，butwhenweareatourjourney’sendwewantthemnolonger。Again，theyareusefulasmentalfluxes，andashelpingustofusenewideaswithourolderones。Theypresentuswithsometagsandendsofideasthatwehavealreadymastered，ontowhichwecanhitchournewones；buttomultiplytheminrespectofsuchamatterasthought，islikescratchingthebiteofagnat；
themorewescratchthemorewewanttoscratch；themorewedefinethemoreweshallhavetogoondefiningthewordswehaveusedinourdefinitions，andshallendbysettingupaseriousmentalrawintheplaceofasmalluneasinessthatwasafterallquiteendurable。
Weknowtoowellwhatthoughtis，tobeabletoknowthatweknowit，andIampersuadedthereisnooneinthisroombutunderstandswhatismeantbythoughtandthinkingwellenoughforallthepurposesofthisdiscussion。Whoeverdoesnotknowthiswithoutwordswillnotlearnitforallthewordsanddefinitionsthatarelaidbeforehim。Themore，indeed，hehears，themoreconfusedhewillbecome。Ishall，therefore，merelypremisethatIusetheword\"thought\"inthesamesenseasthatinwhichitisgenerallyusedbypeoplewhosaythattheythinkthisorthat。Atanyrate，itwillbeenoughifItakeProfessorMaxMuller’sowndefinition，andsaythatitsessenceconsistsinabringingtogetherofmentalimagesandideaswithdeductionstherefrom，andwithacorrespondingpowerofdetachingthemfromoneanother。Hobbes，theProfessortellsus，maintainedthislongago，whenhesaidthatallourthinkingconsistsofadditionandsubtraction——thatistosay，inbringingideastogether，andindetachingthemfromoneanother。
Turningfromthoughttolanguage，weobservethatthewordisderivedfromtheFrenchlangue，ortongue。Strictly，therefore，itmeanstonguage。This，however，takesaccountofbutaverysmallpartoftheideasthatunderlietheword。Itdoes，indeed，seizeafamiliarandimportantdetailofeverydayspeech，thoughitmaybedoubtedwhetherthetonguehasmoretodowithspeakingthanlips，teethandthroathave，butitmakesnoattemptatgraspingandexpressingtheessentialcharacteristicofspeech。Anythingdonewiththetongue，eventhoughitinvolvenospeakingatall，istonguage；eatingorangesisasmuchtonguageasspeechis。Theword，therefore，thoughittellsusinparthowspeechiseffected，revealsnothingofthatulteriormeaningwhichisneverthelessinseparablefromanyrightuseofthewordseither\"speech\"or\"language。\"Itpresentsuswithwhatisindeedaveryfrequentadjunctofconversation，buttheuseofwrittencharacters，orthefinger-speechofdeafmutes，isenoughtoshowthattheword\"language\"omitsallreferencetothemostessentialcharacteristicsoftheidea，whichinpracticeitneverthelessverysufficientlypresentstous。Ihopepresentlytomakeitcleartoyouhowandwhyitshoulddoso。Thewordisincompleteinthefirstplace，becauseitomitsallreferencetotheideaswhichwords，speechorlanguageareintendedtoconvey，andtherecanbenotruewordwithoutitsactuallyorpotentiallyconveyinganidea。Secondly，itmakesnoallusiontothepersonorpersonstowhomtheideasaretobeconveyed。Languageisnotlanguageunlessitnotonlyexpressesfairlydefiniteandcoherentideas，butunlessitalsoconveystheseideastosomeotherlivingintelligentbeing，eithermanorbrute，thatcanunderstandthem。Wemayspeaktoadogorhorse，butnottoastone。Ifwemakepretenceofdoingsoweareinrealityonlytalkingtoourselves。Thepersonoranimalspokentoishalfthebattle——ahalf，moreover，whichisessentialtotherebeinganybattleatall。Ittakestwopeopletosayathing——asayeeaswellasasayer。Theoneisasessentialtoanytruesayingastheother。A。mayhavespoken，butifB。hasnotheard，therehasbeennothingsaid，andhemustspeakagain。True，thebeliefonA。’spartthathehadabonafidesayeeinB。，saveshisspeechquahim，butithasbeenbarrenandleftnofertileissue。Ithasfailedtofulfiltheconditionsoftruespeech，whichinvolvenotonlythatA。