Is，then，thisobligationintuitivelyseentobeindependentandcertain？
Itisoftensaidtobeso:andperhapswemaysaythatitseemssotounreflectivecommonsense。Butreflectionseemsatleasttodiscloseaconsiderablenumberofqualificationsoftheprinciple；
someclearandprecise，whileothersaremoreorlessindefinite。
Inthefirstplace，thoughtfulpersonswouldcommonlyadmitthattheobligationofapromiseisrelativetothepromisee，andmaybeannulledbyhim。Andthereforeifthepromiseebedead，orotherwiseinaccessibleandincapableofgrantingrelease，thereisconstitutedanexceptionalcase，ofwhichthesolutionpresentssomedifficulty。[1]
Secondly，apromisetodoanimmoralactisheldnottobebinding，becausethepriorobligationnottodotheactisparamount；justasinlawacontracttodowhatamanisnotlegallyfreetodo，isinvalid:otherwiseonecouldevadeanymoralobligationbypromisingnottofulfilit，whichisclearlyabsurd。[2]