Theycouldonlyamendtheargumentbysayingthatallmenwereequalinsofarastheypossessedcertainattributes。Butthoseattributescouldonlybedeterminedbyexperience，or，asBenthamwouldhaveputit，byanappealto’utility。’Itisillogical，saidtheanti-slaveryadvocate，totreatmendifferentlyOnaccountofthecolouroftheirskins。Nodoubtitisillogicalif，infact，thedifferenceofcolourdoesnotimplyadifferenceofthepowerswhichfitamanfortheenjoymentofcertainrights。Wemayatleastgrantthattheburdenofproofshouldbeuponthosewhowoulddisfranchiseallred-hairedmen。Butthisisbecauseexperienceshowsthatthedifferenceofcolourdoesnotmarkarelevantdifference。Wecannotsay，apriori，whetherthedifferencebetweenanegroandawhitemanmaynotbesogreatastoimplyincapacityforenjoymentofequalrights。Theblackskinmight——foranythingamerelogiciancansay——indicatethemindofachimpanzee。Thecaseagainstslaverydoesnotrestonthebarefactthatnegroesandwhitesbothbelongtotheclass’man，’butonthefactthatthenegrohaspowersandsensibilitieswhichfithimtoholdproperty，toformmarriages，tolearnhisletters，andsoforth。Butthatfactisundeniablytobeproved，notfromthebarelogic，butfromobservationoftheparticularcase。
Benthamsawwithperfectclearnessthatsoundpoliticaltheoryrequiresabasisofsolidfact。Themainpurposeofhiswholesystemwastocarryoutthatdoctrinethoroughly。Hisviewisgivenvigorouslyinthe’AnarchicalFallacies’——aminuteexaminationoftheFrenchDeclarationofRightsin1791。Hisargumentisofmercilesslength，andoccasionallysominuteastosoundlikequibbling。Thepith，however，isclearenough。’Allmenarebornandremainfreeandequalinrespectofrights’arethefirstwordsoftheDeclaration。Nobodyis’bornfree，’retortsBentham。Everybodyisborn，andlongremains，ahelplesschild。Allmenbornfree！Absurdandmiserablenonsense！Why，youarecomplaininginthesamebreaththatnearlyeverybodyisaslave。97*Tomeetthisobjection，thewordsmightbeamendedbysubstituting’oughttobe’for’is。’This，however，onBentham’sshowing，atonceintroducestheconceptionofutility，andthereforeleadstoempiricalconsiderations。
Theproposition，whenlaiddownasalogicalnecessity，claimstobeabsolute。
Thereforeitimpliesthatallauthorityisbad；theauthority，forexample，ofparentoverchild，orofhusbandoverwife；andmoreover，thatalllawstothecontraryareipsofactovoid。Thatiswhyitis’anarchical。’Itsupposesa’naturalright，’notonlyassuggestingreasonsforproposedalterationsofthelegalright，butasactuallyannihilatingtherightandthereforedestroyingallgovernment。’Naturalrights，’saysBentham，98*issimplenonsense；naturalandimprescriptiblerights’rhetoricalnonsense——nonsenseuponstilts。’For’naturalright’substituteutility，andyouhave，ofcourse，areasonableprinciple，becauseanappealtoexperience。Butlaydown’liberty’
asanabsoluterightandyouannihilatelaw，foreverylawsupposescoercion。