Sincetheexchange—valueofcommoditiesisindeednothingbutamutualrelationbetweenvariouskindsoflabourofindividualsregardedasequalanduniversallabour,i。e。,nothingbutamaterialexpressionofaspecificsocialformoflabour,itisatautologytosaythatlabouristheonlysourceofexchange—valueandaccordinglyofwealthinsofarasthisconsistsofexchange—value。Itisequallyatautologytosaythatmaterialinitsnaturalstatedoesnothaveexchange—value[5]sinceitcontainsnolabour,andthatexchange—valueassuchincludesnomaterialinanaturalstate。ItistruethatWilliamPettycalls"labourthefatherandearththemotherofwealth",BishopBerkeleyasks"whetherthefourelements,andman'slabourtherein,benotthetruesourceofwealth",[6]
　　andtheAmericanThomasCooperexplainsinpopularform:
　　"Takeawayfromapieceofbreadthelabourbestowedbythebakerontheflour,bythemilleronthegrainbroughttohim,bythefarmerinploughing,sowing,tending,gathering,threshing,cleaningandtransportingtheseed,andwhatwillremain？Afewgrainsofgrass,growingwildinthewoods,andunfitforanyhumanpurpose。"[7]
　　Butalltheseobservationsareconcernednotwithabstractlabour,whichisthesourceofexchange—value,butwithconcretelabourasthesourceofmaterialwealth,inshortwithlabourinsofarasitproducesuse—values。
　　Sincetheuse—valueofthecommodityispostulated,thespecificutilityandthedefiniteusefulnessofthelabourexpendedonitisalsopostulated;
　　butthisistheonlyaspectoflabourasusefullabourwhichisrelevanttothestudyofcommodities。Inconsideringbreadasause—value,weareconcernedwithitspropertiesasanarticleoffoodandbynomeanswiththelabourofthefarmer,miller,baker,etc。Evenifthelabourrequiredwerereducedby95percentasaresultofsomeinvention,theusefulnessofaloafofbreadwouldremainquiteunaffected。Itwouldlosenotasingleparticleofitsuse—valueevenifitdroppedready—madefromthesky。Whereaslabourpositingexchange—valuemanifestsitselfintheequalityofcommoditiesasuniversalequivalents,labourasusefulproductiveactivitymanifestsitselfintheinfinitevarietyofuse—values。Whereaslabourpositingexchange—valueisabstrectuniversalandunifornlabour,labourpositinguse—valueisconcreteanddistinctivelabour,comprisinginfinitelyvaryingkindsoflabourasregardsitsformandthematerialtowhichitisapplied。
　　Itwouldbewrongtosaythatlabourwhichproducesuse—valuesistheonlysourceofthewealthproducedbyit,thatisofmaterialwealth。Sincelabourisanactivitywhichadaptsmaterialforsomepurposeorother,itneedsmaterialasaprerequisite。Differentuse—valuescontainverydifferentproportionsoflabourandnaturalproducts,butuse—valuealwayscomprisesanaturalelement。Asusefulactivitydirectedtotheappropriationofnaturalfactorsinoneformoranother,labourisanaturalconditionofhumanexistence,aconditionofmaterialinterchangebetweenmanandnature,quiteindependentoftheformofsociety。Ontheotherhand,thelabourwhichpositsexchange—valueisaspecificsocialformoflabour。
　　Forexample,tailoringifoneconsidersitsphysicalaspectasadistinctproductiveactivityproducesacoat,butnottheexchange—valueofthecoat。Theexchange—valueisproducedbyitnotastailoringassuchbutasabstractuniversallabour,andthisbelongstoasocialframeworknotdevisedbythetailor。Womeninancientdomesticindustry,forinstance,producedcoatswithoutproducingtheexchange—valueofcoats。LabourassourceofmaterialwealthwaswellknownbothtoMoses,thelaw—giver,andtoAdamSmith,thecustomsofficial。[8]
　　Letusnowexamineafewpropositionswhichfollowfromthereductionofexchange—valuetolabour—time。
　　Acommodityasause—valuehasaneminentlymaterialfunction。Wheatforexampleisusedasfood。Amachinereplacesacertainamountoflabour。
　　Thisfunction,byvirtueofwhichacommodityisause—value,anarticleofconsumption,maybecalleditsservice,theserviceitrendersasause—value。Butthecommodityasanexchange—valueisalwaysconsideredsolelyfromthestandpointoftheresult。Whatmattersisnottheserviceitrenders,buttheservice[9]renderedtoitinthecourseofitsproduction。Thustheexchange—valueofamachine,forinstance,isdeterminednotbytheamountoflabour—timewhichitcanreplace,butbytheamountoflabour—timeexpendedinitsproductionandthereforerequiredfortheproductionofanewmachineofthesametype。
　　Thus,iftheamountoflabourrequiredfortheproductionofcommoditiesremainedconstant,theirexchange—valuewouldalsoremainunchanged。Butthefacilityordifficultyofproductionvariescontinually。Iftheproductivityoflabourgrows,thesameuse—valuewillbeproducedinlesstime。If~theproductivityoflabourdeclines,moretimewillbeneededtoproducethesameuse—value。Theamountoflabour—timecontainedinacommodity,andthereforeitsexchange—value,isconsequentlyavariablequantity,risingorfallingininverseproportiontotheriseorfalloftheproductivityoflabour。Theleveloftheproductivityoflabour,whichispredeterminedinmanufacturingindustry,dependsinagricultureandextractiveindustryalsouponunpredictablenaturalconditions。Thesamequantityoflabourwillresultinalargerorsmalleroutputofvariousmetals——dependingontherelativeabundanceofthedepositsofthesemetalsintheearth'scrust。Thesameamountoflabourmayyieldtwobushelsofwheatinafavourableseason,andperhapsonlyonebushelinanunfavourableseason。Scarcityorabundancebroughtaboutbynaturalcircumstancesseemsinthiscasetodeterminetheexchange—valueofcommodities,becauseitdeterminestheproductivityofthespecificconcretelabourwhichisboundupwiththenaturalconditions。
　　Equalamountsoflabour—time,orequalamountsofexchange—value,arecontainedinunequalvolumesofdifferentuse—values。Thesmallerthevolumeofause—valuewhichcontainsagivenamountoflabour—timeascomparedwithotheruse—valuesofcommodities,thegreateristhespecificexchange—valueofthatcommodity。Ifwefindthatindifferentepochsofcivilisationseparatedbylongperiodsoftime,varioususe—values——forexamplegold,silver,copperandiron,orwheat,rye,barleyandoats——formaseriesofspecificexchange—valueswhichonthewholeretaintheirrelativeorderinrelationtooneanother,thoughnottheirexactnumericalproportions,itfollowsthattheprogressivedevelopmentofthesocialproductiveforceshasexertedauniformornearlyuniformeffectonthelabour—timerequiredfortheproductionofthesecommodities。
　　Theexchange—valueofacommodityisnotexpressedinitsownuse—value。
　　Butasmaterialisationofuniversalsociallabour—time,theuse—valueofonecommodityisbroughtintorelationwiththeuse—valuesofothercommodities。
　　Theexchange—valueofonecommoditythusmanifestsitselfintheuse—valuesofothercommodities。Infacttheexchange—valueofonecommodityexpressedintheuse—valueofanothercommodityrepresentsequivalence。Ifonesays,forinstance,oneyardoflinenisworthtwopoundsofcoffee,thentheexchange—valueoflinenisexpressedintheuse—valueofcoffee,anditismoreoverexpressedinadefinitequantityofthisuse—value。Oncetheproportionisgiven,thevalueofanyquantityoflinencanbeexpressedintermsofcoffee。Itisevidentthattheexchange—valueofacommodity,e。g。,linen,isnotexhaustivelyexpressedbytheproportioninwhichaparticularcommodity,e。g。,coffee,formsitsequivalent。Thequantityofuniversallabour—timerepresentedbyayardoflinenexistssimultaneouslyininfinitelyvariedamountsoftheuse—valuesofallothercommodities。
　　Theuse—valueofanyothercommoditytakenintheproportionwhichrepresentsthesamequantityoflabour—timeconstitutesanequivalentfortheyardoflinen。Theexchange—valueofthisparticularcommoditycanthereforebeexhaustivelyexprcssedonlybytheinfinitenumberofequationsinwhichtheuse—valuesofallothercommoditiesformitsequivalent。Theonlyexhaustiveexpressionforauniversalequivalentisthesumoftheseequationsorthetotalityofthedifferentproportionsinwhichacommoditycanbeexchangedforanyothercommodity。Forexampletheseriesofequations——
　　1yardoflinen=1/2lb。oftea1yardoflinen=2lbs。ofcoffee1yardoflinen=8lbs。ofbread1yardoflinen=6yardsofcalicomaybeputinthefollowingform——
　　1yardoflinen=t/8lb。oftea1/2lb。ofcoffee2lbs。Ofbread11/2yardsofcalico。
　　Thusifwehadalltheequationsinwhichthevalueofayardoflinenisexhaustivelyexpressed,wecoulddenoteitsexchange—valueintheformofaseries。Thisisinfactaninfiniteseries,fortherangeofcommoditiescanneverbefinallycircumscribedbutexpandscontinuously。Sincetheexchange—valueofonecommodityismeasuredbytheuse—valuesofallothercommodities,theexchange—valuesofallothercommoditiesareonthecontrarymeasuredintermsoftheuse—valueoftheonecommoditymeasuredbythem。[10]Iftheexchange—valueofoneyardoflinenisexpressedin1/2lb。oftea,or2lbs。ofcoffee,or6yardsofcalico,or8lbs。Ofbread,etc。,itfollowsthatcoffee,tea,calico,bread,etc。,mustbeequaltooneanotherintheproportioninwhichtheyareequaltolinen,athirdmagnitude,linenthusservesasacommonmeasureoftheirexchange—value。Theexchange—valueofanycommodityconsideredasmaterialiseduniversallabour—time,。e。,asadefinitequantityofuniversallabour—time,ismeasuredsuccessivelyintermsofdefinitequantitiesoftheuse—valuesofallothercommodities;
　　andontheotherhandtheexchange—valuesofallothercommoditiesaremeasuredintheuse—valueofthisoneexclusivecommodity。Butanycommodityconsideredasexchange—valueisboththeexclusivecommoditywhichservesasthecommonmeasureoftheexchange—valuesofallothercommoditiesandontheotherhanditismerelyonecommodityofthemanycommoditiesintheseriesinwhichtheexchange—valueofanyothercommodityisdirectlyexpressed。
　　Theexistingnumberofdifferenttypesofcommoditiesdoesnotaffectthevalueofacommodity。Butwhethertheseriesofequationsinwhichitsexchange—valuecanberealisedislongerorshorterdependsonthegreaterorsmallervarietyofdifferentcommodities。Theseriesofequationswhichexpress,say,thevalueofcoffeeshowstherangeofitsexchangeability,thelimitswithinwhichitfunctionsasanexchange—value。
　　Theexchange—valueofacommodityastheobjectiveexpressionofuniversalsociallabour—timefindsitsappropriateexpressionofequivalenceintheinfinitevarietyofuse—values。
　　Wehaveseenthattheexchange—valueofacommodityvarieswiththequantityoflabour—timedirectlycontainedinit。Itsrealisedexchange—value,thatisitsexchange—valueexpressedintheuse—valuesofothercommodities,mustalsodependonthedegreetowhichthelabour—timeexpendedontheproductionofallothercommoditiesvaries。Forexample,ifthelabour—timenecessaryfortheproductionofabushelofwheatremainedunchanged,whilethelabour—timeneededfortheproductionofallothercommoditiesdoubled,theexchange—valueofabushelofwheatintermsofitsequivalentswouldhavebeenhalved。Theresultwouldactuallybethesameasifthelabour—timerequiredtoproduceabushelofwheathadbeenhalvedandthelabour—timerequiredtoproduceallothercommoditieshadremainedunchanged。Thevalueofcommoditiesisdeterminedbytheamountofthemwhichcanbeproducedinagivenlabour—time。Inordertoexaminewhatchangesareliabletoaffectthisproportion,letustaketwocommodities,AandB。FirstThelabour—timerequiredfortheproductionofBisassumedtoremainunchanged。
　　Inthiscasetheexchange—valueofAexpressedintermsofBfallsorrisesindirectproportiontothedecreaseorincreaseinthelabour—timenecessaryfortheproductionofA。Secondly。Thelabour—timenecessaryfortheproductionofcommodityAisassumedtoremainunchanged。Theexchange—valueofcommodityAintermsofBfallsorrisesininverseproportiontothedecreaseorincreaseinthelabour—timerequiredtoproduceB。Thirdly。Thelabour—timerequiredfortheproductionofAandofBisassumedtodecreaseorincreaseatthesamerate。TheequationexpressingthevalueofcommodityAintermsofBremainsunchangedinthiscase。Ifsomefactorweretocausetheproductivityofalltypesoflabourtofallinequaldegree,thusrequiringthesameproportionofadditionallabourfortheproductionofallcommodities,thenthevalueofallcommoditieswouldrise,theactualexpressionoftheirexchange—valueremainingunchanged,andtherealwealthofsocietywoulddecrease,sincetheproductionofthesamequantityofuse—valueswouldrequirealargeramountoflabour—time。Fourthly。Thelabour—timerequiredfortheproductionofbothAandBisassumedtoincreaseordecreasebutinunequaldegree,orelsethelabour—timerequiredfortheproductionofAisassumedtoincreasewhilethatrequiredforBdecreases,orviceversa。Allthesecasescanbesimplyreducedtothepositionwherethelabour—timerequiredfortheproductionofonecommodityremainsunchanged,whilethatrequiredfortheproductionoftheothereitherincreasesordecreases。
　　Theexchange—valueofanycommodityisexpressedintermsoftheuse—valueofanyothercommodity,eitherinwholeunitsorinfractionsofthatuse—value。
　　Everycommodityasexchange—valuecanbejustaseasilydividedasthelabour—timecontainedinit。Theequivalenceofcommoditiesisjustasindependentofthephysicaldivisibilityoftheiruse—valuesasthesummationoftheexchange—valuesofcommoditiesisunaffectedbythechangeswhichtheuse—valuesofthecommoditiesmayundergointhecourseoftheirtransformationintoasinglenewcommodity。
　　Sofartwoaspectsofthecommodity——use—valueandexchange—value——havebeenexamined,buteachoneseparately。Thecommodity,however,isthedirectunityofuse—valueandexchange—value,andatthesametimeitisacommodityonlyinrelationtoothercommodities。Theexchangeprocessofcommoditiesistherealrelationthatexistsbetweenthem。Thisisasocialprocesswhichiscarriedonbyindividualsindependentlyofoneanother,buttheytakepartinitonlyascommodity—owners;
　　theyexistforoneanotheronlyinsofarastheircommoditiesexist;theythusappeartobeinfacttheconsciousrepresentativesoftheexchangeprocess。
　　Thecommodityisause—value,wheat,linen,adiamond,machinery,etc。,butasacommodityitissimultaneouslynotause—value。Itwouldnotbeacommodity,ifitwereause—valueforitsowner,thatisadirectmeansforthesatisfactionofhisownneeds。Foritsowneritisonthecontraryanon—use—value,thatismerelythephysicaldepositoryofexchange—value,orsimplyameansofexchange。Use—valueasanactivecarrierofexchange—valuebecomesameansofexchange。Thecommodityisause—valueforitsowneronlysofarasitisanexchange—value。
　　[ItisinthissensethatAristotlespeaksofexchange—value（seethepassagequotedatthebeginningofthischapter）。]Thecommoditythereforehasstilltobecomeause—value,inthefirstplaceause—valueforothers。Sinceitisnotause—valuetoitsowner,itmustbeause—valuetoownersofothercommodities。Ifthisisnotthecase,thenthelabourexpendedonitwasuseless;labourandtheresultaccordinglyisnotacommodity。Thecommoditymust,ontheotherhand,becomeause—valueforitsowner,sincehismeansofexistenceexistoutsideit,intheuse—valuesofotherpeople'scommodities。Tobecomeause—value,thecommoditymustencountertheparticularneedwhichitcansatisfy。Thustheuse—valuesofcommoditiesbecomeuse—valuesbyamutualexchangeofplaces:theypassfromthehandsofthoseforwhomtheyweremeansofexchangeintothehandsofthoseforwhomtheyserveasconsumergoods。Onlyasaresultofthisuniversalalienationofcommoditiesdoesthelabourcontainedinthembecomeusefullabour。Commoditiesdonotacquireaneweconomicforminthecourseofmutualrelationsasuse—values。Onthecontrary,thespecificformwhichdistinguishedthemascommoditiesdisappears。Bread,forinstance,inpassingfromthebakertotheconsumerdoesnotchangeitscharacterasbread。Itisratherthattheconsumertreatsitasause—
　　value,asaparticularfoodstuff,whereassolongasitwasinthehandsofthebakeritwassimplyrepresentativeofaneconomicrelation,aconcreteandatthesametimeanabstractthing。Theonlytransformationthereforethatcommoditiesexperienceinthecourseofbecominguse—valuesisthecessationoftheirformalexistenceinwhichtheywerenon—use—valuesfortheirowner,anduse—valuesfortheirnon—owner。Tobecomeuse—valuescommoditiesmustbealtogetheralienated;theymustenterintotheexchangeprocess;
　　exchangehoweverisconcernedmerelywiththeiraspectasexchange—values。
　　Hence,onlybebeingrealizedasexchange—valuescantheyberealizedasuse—values。
　　Theindividualcommodityasause—valuewasoriginallyregardedassomethingindependent,whileasanexchange—valueitwasfromtheoutsetregardedinitsrelationtoallothercommoditiesButthiswasmerelyatheoretical,hypothetical,relation。Itrealisesitselfonlyintheprocessofexchange。
　　Ontheotherhand,acommodityisanexchange—valueinsofarasadefiniteamountoflabour—timehasbeenexpendedonitsproductionanditaccordinglyrepresentsmaterialisedlabour—time。Yetthecommodityasitcomesintobeingisonlymaterialisedindividuallabour—timeofaspecifickind,andnotuniversallabour—time。Thecommodityisthusnotimmediatelyexchange—value,buthasstilltobecomeexchange—value。Tobeginwith,itcanbematerialisationofuniversallabour—timeonlywhenitrepresentsaparticularusefulapplicationoflabour—time,thatisause—value。Thisisthematerialconditionunderwhichalonethelabour—timecontainedincommoditiesisregardedasuniversal,sociallabour—time。Acommoditycanonlythereforebecomeause—valueifitisrealisedasanexchange—value,whileitcanonlyberealisedasanexchange—valueifitisalienatedandfunctionsasause—value。Thealienationofacommodityasause—valueisonlypossibletothepersonforwhomitisause—value,i。e。,anobjectsatisfyingparticularneeds。Ontheotherhand,itcanonlybealienatedinexchangeforanothercommodity,orifweregardthematterfromthestandpointoftheowneroftheothercommodity,hetoocanonlyalienate,i。e。,realise,hiscommoditybybringingitintocontactwiththeparticularneedofwhichitistheobject。Duringtheuniversalalienationofcommoditiesasuse—valuestheyarebroughtintorelationwithoneanotherasdiscretethingswhicharephysicallydifferentandbecauseoftheirspecificpropertiessatisfyparticularneeds。Butasmereuse—valuestheyexistindependentlyofoneanotherorratherwithoutanyconnection。Theycanbeexchangedasuse—valuesonlyinconnectionwithparticularneeds。Theyare,however,exchangeableonlyasequivalents,andtheyareequivalentsonlyasequalquantitiesofmaterialisedlabour—time,whentheirphysicalpropertiesasuse—values,andhencetherelationsofthesecommoditiestospecificneeds,areentirelydisregarded。Acommodityfunctionsasanexchange—valueifitcanfreelytaketheplaceofadefinitequantityofanyothercommodity,irrespectiveofwhetherornotitconstitutesause—valuefortheowneroftheothercommodity。Butfortheowneroftheothercommodityitbecomesacommodityonlyinsofarasitconstitutesause—valueforhim,andfortheownerinwhosehandsitisitbecomesanexchange—valueonlyinsofarasitisacommodityfortheotherowner。
　　Oneandthesamerelationmustthereforebesimultaneouslyarelationofessentiallyequalcommoditieswhichdifferonlyinmagnitude,i。e。,arelationwhichexpressestheirequalityasmaterialisationsofuniversallabour—time,andatthesametimeitmustbetheirrelationasqualitativelydifferentthings,asdistinctuse—valuesfordistinctneeds,inshortarelationwhichdifferentiatesthemasactualuse—valuesButequalityandinequalitythuspositedaremutuallyexclusive。Theresultisnotsimplyaviciouscircleofproblems,wherethesolutionofoneproblempresupposesthesolutionoftheother,butawholecomplexofcontradictorypremises,sincethefulfillmentofoneconditiondependsdirectlyuponthefulfillmentofitsopposite。
　　Theexchangeprocessmustcompriseboththeevolutionandthesolutionofthesecontradictions,whichcannothoweverbedemonstratedintheprocessinthissimpleformWehavemerelyobservedhowthecommoditiesthemselvesarerelatedtooneanotherasuse—values,i。e。,howcommoditiesasuse—valuesfunctionwithintheexchangeprocess。Ontheotherhand,exchange—valueaswehaveconsideredittillnowhasmerelyexistedasourabstraction,or,ifoneprefers,astheabstractionoftheindividualcommodity—owner,whokeepsthecommodityasuse—valueintheware—house,andhasitonhisconscienceasexchange—value。Intheexchangeprocess,however,thecommoditiesmustexistforoneanothernotonlyasuse—valuesbutalsoasexchange—values,andthisaspectoftheirexistencemustappearastheirownmutualrelation。Thedifficultywhichconfrontedusinthefirstplacewasthatthecommodityasause—valuehastobealienated,disposedof,beforeitcanfunctionasanexchange—value,asmaterialisedlabour,whileonthecontraryitsalienationasause—valuepresupposesitsexistenceasexchange—value。Butletussupposethatthisdifficultyhasbeenovercome,thatthecommodityhassheditsparticularuse—valueandhastherebyfulfilledthematerialconditionofbeingsociallyusefullabour,insteadoftheparticularlabourofanindividualbyhimself。Intheexchangeprocess,thecommodityasexchange—valuemustthenbecomeauniversalequivalent,materialisedgenerallabour—timeforallothercommodities;ithasthusnolongerthelimitedfunctionofaparticularuse—value,butiscapableofbeingdirectlyrepresentedinalluse—valuesasitsequivalents。Everycommodityhoweveristhecommoditywhich,asaresultofthealienationofitsparticularuse—value,mustappearasthedirectmaterialisationofuniversallabour—time。Butontheotherhand,onlyparticularcommodities,particularuse—valuesembodyingthelabourofprivateindividuals,confrontoneanotherintheexchangeprocess。Universallabour—timeitselfisanabstractionwhich,assuch,doesnotexistforcommodities。
　　Letusconsidertheseriesofequationsinwhichtheexchange—valueofacommodityisexpressedinconcreteterms,forexample——
　　1yardoflinen=2lbs。ofcoffee1yardoflinen=1/2lb。oftea1yardoflinen=8lbs。ofbread,etc。Tobesure,theseequationsmerelydenotethatequalamountsofuniversalsociallabour—timearematerialisedin1yardoflinen,2lbs。ofcoffee,1/2lb。oftea,etc。Butthedifferentkindsofindividuallabourrepresentedintheseparticularuse—values,infact,becomelabouringeneral,andinthiswaysociallabour,onlybyactuallybeingexchangedforoneanotherinquantitieswhichareproportionaltothelabour—timecontainedinthem。
　　Sociallabour—timeexistsinthesecommoditiesinalatentstate,sotospeak,andbecomesevidentonlyinthecourseoftheirexchange。Thepointofdepartureisnotthelabourofindividualsconsideredassociallabour,butonthecontrarytheparticularkindsoflabourofprivateindividuals,i。e。,labourwhichprovesthatitisuniversalsociallabouronlybythesupersessionofitsoriginalcharacterintheexchangeprocess。Universalsociallabourisconsequentlynotaready—madeprerequisitebutanemergingresult。Thusanewdifficultyarises:ontheonehand,commoditiesmustentertheexchangeprocessasmaterializeduniversallabour—time,ontheotherhand,thelabour—timeofindividualsbecomesmaterializeduniversallabour—timeonlyastheresultoftheexchangeprocess。
　　Itisthroughthealienationofitsuse—value,thatisofitsoriginalformofexistence,thateverycommodityhastoacquireitscorrespondingexistenceasexchange—value。Thecommoditymustthereforeassumeadualformexistenceintheexchangeprocess。Ontheotherhand,itssecondformofexistence,exchange—value,canonlyberepresentedbyanothercommodity,foronlycommoditiesconfrontoneanotherintheexchangeprocess。Howisitpossibletopresentaparticularcommoditydirectlyasmaterialiseduniversallabour—time,or——whichamountstothesamething——howcantheindividuallabour—timematerialisedinaparticularcommoditydirectlyassumeauniversalcharacter？Theconcreteexpressionoftheexchange—valueofacommodity,i。e。,ofanycommodityconsideredasuniversalequivalent,consistsofaninfiniteseriesofequationssuchas——
　　1yardoflinen=2lbs。ofcoffee1yardoflinen=1/2lb。oftea1yardoflinen=8lbs。ofbread1yardoflinen=6yardsofcalico1yardoflinen=andsoon。Thisisatheoreticalstatementsincethecommodityismerelyregardedasadefinitequantityofmaterialiseduniversallabour—time。Aparticularcommodityasauniversalequivalentistransformedfromapureabstractionintoasocialresultoftheexchangeprocess,ifonesimplyreversestheaboveseriesofequations。Forexample——
　　2lbs。ofcoffee=1yardoflinen1/2lb。oftea=1yardoflinen8lbs。ofbread=1yardoflinen6yardsofcalico=1yardoflinen。Justasthelabour—timecontainedincoffee,tea,bread,calico,inshortinallcommodities,isexpressedintermsoflinen,soconverselytheexchange—valueoflinenisreflectedinallothercommoditieswhichactasitsequivalents,andthelabour—timematerialisedinlinenbecomesdirectuniversallabour—time,whichisequallyembodiedindifferentvolumesofallothercommodities。
　　Linenthusbecomestheuniversalequivalentinconsequenceoftheuniversalactionofallothercommoditiesinrelationtoit。Everycommodityconsideredasexchange—valuebecameameasureofthevalueofallothercommodities。Inthiscase,onthecontrary,becausetheexchange—valueofallcommoditiesismeasuredintermsofoneparticularcommodity,theexcludedcommoditybecomestheadequaterepresentationofexchange—valueastheuniversalequivalent。Ontheotherhand,theinfiniteseriesortheinfinitenumberofequationsinwhichtheexchange—valueofeachcommoditywasexpressedisnowreducedtoasingleequationconsistingoftwoterms。
　　Theequation2lbs。ofcoffee=1yardoflinenisnowacomprehensiveexpressionfortheexchange—valueofcoffee,forinthisexpressionitappearsasthedirectequivalenttoadefinitequantityofanyothercommodity。
　　Commoditieswithintheexchangeprocessaccordinglyexistforoneanother,orappeartooneanother,asexchange—valuesintheformoflinen。Thefactthatallcommoditiesarerelatedtooneanotherasexchange—values！
　　i。e。,simplyasdifferentquantitiesofmaterialiseduniversallabour—time,nowappearsintheformthatallexchange—valuesrepresentmerelydifferentquantitiesofoneandthesamearticle,linen。Universallabour—timethusappearsasaspecificthing,asacommodityinadditiontoandapartfromallothercommodities。Atthesametime,theequationinwhichonecommodityrepresentstheexchange—valueofanothercommodity,e。g。,2lbs。
　　ofcoffee=1yardoflinen,hasstilltoberealised。Onlybybeingalienatedasause—value——analienationwhichdependsonwhetheritisabletoproveintheexchangeprocessthatitisaneededobject——isitreallyconvertedfromtheformofcoffeeintothatoflinen,thusbecomingauniversalequivalentandreallyrepresentingexchange—valueforallothercommodities。
　　Ontheotherhand,becauseasaresultoftheiralienationasuse—valuesallcommoditiesareconvertedintolinen,linenbecomestheconvertedformofallothercommodities,andonlyasaresultofthistransformationofallothercommoditiesintolinendoesitbecomethedirectreificationofuniversallabour—time,i。e。,theproductofuniversalalienationandofthesupersessionofallindividuallabour。Whilecommoditiesthusassumeadualforminordertorepresentexchange—valueforoneanother,thecommoditywhichhasbeensetapartasuniversalequivalentacquiresadualuse—value。Inadditiontoitsparticularuse—valueasanindividualcommodityitacquiresauniversaluse—value。Thislatteruse—valueisitselfadeterminateform,i。e。,itarisesfromthespecificrolewhichthiscommodityplaysasaresultoftheuniversalactionexertedonitbytheothercommoditiesintheexchangeprocess。Theuse—valueofeachcommodityasanobjectwhichsatisfiesparticularneedshasadifferentvalueindifferenthands,e。g。,ithasonevalueforthepersonwhodisposesofitandadifferentvalueforthepersonwhoacquiresit。Thecommoditywhichhasbeensetapartastheuniversalequivalentisnowanobjectwhichsatisfiesauniversalneedarisingfromtheexchangeprocessitself,andhasthesameuse—valueforeverybody——thatofbeingcarrierofexchange—valueorauniversalmediumofexchange。