Sincethedeterminationofexchange—valuebylabour—timehasbeenformulatedandexpoundedintheclearestmannerbyRicardo,whogavetoclassicalpoliticaleconomyitsfinalshape,itisquitenaturalthattheargumentsraisedbyeconomistsshouldbeprimarilydirectedagainsthim。Ifthispolemicisstrippedofitsmainlytrivial[19]formitcanbesummarisedasfollows:
One。Labouritselfhasexchange—valueanddifferenttypesoflabourhavedifferentexchange—values。Ifonemakesexchange—valuethemeasureofexchange—value,oneiscaughtupinaviciouscircle,fortheexchange—valueusedasameasurerequiresinturnameasure。Thisobjectionmergesintothefollowingproblem:givenlabour—timeastheintrinsicmeasureofvalue,howarewagestobedeterminedonthisbasis。
Thetheoryofwage—labourprovidestheanswertothis。
Two。Iftheexchange—valueofaproductequalsthelabour—timecontainedintheproduct,thentheexchange—valueofaworkingdayisequaltotheproductityields,inotherwords,wagesmustbeequaltotheproductoflabour。[20]Butinfacttheoppositeistrue。Ergo,thisobjectionamountstotheproblem,——howdoesproductiononthebasisofexchange—valuesolelydeterminedbylabour—timeleadtotheresultthattheexchange—valueoflabourislessthantheexchange—valueofitsproduct？Thisproblemissolvedinouranalysisofcapital。
Three。Inaccordancewiththechangingconditionsofdemandandsupply,themarket—priceofcommoditiesfallsbeloworrisesabovetheirexchange—value。Theexchange—valueofcommoditiesis,consequently,determinednotbythelabour—timecontainedinthem,butbytherelationofdemandandsupply。Infact,thisstrangeconclusiononlyraisesthequestionhowonthebasisofexchange—valueamarket—pricedifferingfromthisexchange—valuecomesintobeing,orrather,howthelawofexchange—valueassertsitselfonlyinitsantithesis。Thisproblemissolvedinthetheoryofcompetition。