Onesuchprinciplewasgiveninchap。i。§；3
ofthisBook；whereIpointedoutthatwhateveractionanyofusjudgestoberightforhimself，heimplicitlyjudgestoberightforallsimilarpersonsinsimilarcircumstances。Or，aswemayotherwiseputit，`ifakindofconductthatisrightorwrongformeisnotrightorwrong
forsomeoneelse，itmustbeonthegroundofsomedifferencebetweenthetwocases，otherthanthefactthatIandhearedifferentpersons。’
Acorrespondingpropositionmaybestatedwithequaltruthinrespectofwhatoughttobedoneto——notby——differentindividuals。
Theseprincipleshavebeenmostwidelyrecognised，notintheirmostabstractanduniversalform，butintheirspecialapplicationtothesituationoftwoormoreindividualssimilarlyrelatedtoeachother:assoapplied，theyappearinwhatispopularlyknownastheGoldenRule，`Dotoothersasyouwouldhavethemdotoyou。’Thisformulaisobviouslyunpreciseinstatement；foronemightwishforanother’sco-operationinsin，andbewillingtoreciprocateit。Norisiteventruetosaythatweoughttodotoothersonlywhatwethinkitrightforthemtodotous；fornoonewilldenythattheremaybedifferencesinthecircumstances——andeveninthenatures——oftwoindividuals，AandB，whichwouldmakeitwrongforAtotreatBinthewayinwhichitisrightforBtotreatA。