Butthepossibilityitselfisconditionedbysubjectiveandobjectivenaturalcircumstances。Andheretooliesnothingatallmysterious。Shouldlabour-powerbeminute，andthenaturalconditionsoflabourscanty，thenthesurplus-labourissmall，butinsuchacasesoarethewantsoftheproducersontheonehandandtherelativenumberofexploitersofsurplus-labourontheother，andfinallysoisthesurplus-product，wherebythisbarelyproductivesurplus-labourisrealisedforthosefewexploitinglandowners。
Finally，labourrentinitselfimpliesthat，allothercircumstancesremainingequal，itwilldependwhollyupontherelativeamountofsurplus-labour，orenforcedlabour，towhatextentthedirectproducershallbeenabledtoimprovehisowncondition，toacquirewealth，toproduceanexcessoverandabovehisindispensablemeansofsubsistence，or，ifwewishtoanticipatethecapitalistmodeofexpression，whetherheshallbeabletoproduceaprofitforhimself，andhowmuchofaprofit，i。e。，anexcessoverhiswageswhichhavebeenproducedbyhimself。Renthereisthenormal，all-absorbing，sotosaylegitimateformofsurplus-labour，andfarfrombeingexcessoverprofit，whichmeansinthiscasebeingaboveanyotherexcessoverwages，itisratherthattheamountofsuchprofit，andevenitsveryexistence，depends，othercircumstancesbeingequal，upontheamountofrent，i。e。，theenforcedsurplus-labourtobesurrenderedtothelandowners。
Sincethedirectproducerisnottheowner，butonlyapossessor，andsinceallhissurplus-labourdejureactuallybelongstothelandlord，somehistorianshaveexpressedastonishmentthatitshouldheatallpossibleforthosesubjecttoenforcedlabour，orserfs，toacquireanyindependentproperty，orrelativelyspeaking，wealth，undersuchcircumstances。However，itisevidentthattraditionmustplayadominantroleintheprimitiveandundevelopedcircumstancesonwhichthesesocialproductionrelationsandthecorrespondingmodeofproductionarebased。Itisfurthermoreclearthathereasalwaysitisintheinterestoftherulingsectionofsocietytosanctiontheexistingorderaslawandtolegallyestablishitslimitsgiventhroughusageandtradition。Apartfromallelse，this，bytheway，comesaboutofitselfassoonastheconstantreproductionofthebasisoftheexistingorderanditsfundamentalrelationsassumesaregulatedandorderlyforminthecourseoftime。Andsuchregulationandorderarethemselvesindispensableelementsofanymodeofproduction，ifitistoassumesocialstabilityandindependencefrommerechanceandarbitrariness。
Thesearepreciselytheformofitssocialstabilityandthereforeitsrelativefreedomfrommerearbitrarinessandmerechance。Underbackwardconditionsoftheproductionprocessaswellasthecorrespondingsocialrelations，itachievesthisformbymererepetitionoftheirveryreproduction。
Ifthishascontinuedonforsometime，itentrenchesitselfascustomandtraditionandisfinallysanctionedasanexplicitlaw。However，sincetheformofthissurplus-labour，enforcedlabour，isbasedupontheimperfectdevelopmentofallsocialproductivepowersandthecrudenessofthemethodsoflabouritself，itwillnaturallyabsorbarelativelymuchsmallerportionofthedirectproducer抯totallabourthanunderdevelopedmodesofproduction，particularlythecapitalistmodeofproduction。Takeit，forinstance，thattheenforcedlabourforthelandlordoriginallyamountedtotwodaysperweek。Thesetwodaysofenforcedlabourperweekaretherebyfixed，areaconstantmagnitude，legallyregulatedbyprescriptiveorwrittenlaw。Buttheproductivityoftheremainingdaysoftheweek，whichareatthedisposalofthedirectproducerhimself，isavariablemagnitude，whichmustdevelopinthecourseofhisexperience，justasthenewwantsheacquires，andjustastheexpansionofthemarketforhisproductandtheincreasingassurancewithwhichhedisposesofthisportionofhislabour-powerwillspurhimontoagreaterexertionofhislabour-power，wherebyitshouldnotbeforgottenthattheemploymentofhislabour-powerisbynomeansconfinedtoagriculture，butincludesruralhomeindustry。