Asthedifferentrulesofmoralityadmitsuchdifferentdegreesofaccuracy，thoseauthorswhohaveendeavouredtocollectanddigestthemintosystemshavedoneitintwoDifferentmanners；andonesethasfollowedthroughthewholethatloosemethodtowhichtheywerenaturallydirectedbytheconsiderationofonespeciesofvirtues；whileanotherhasasuniversallyendeavouredtointroduceintotheirpreceptsthatsortofaccuracyofwhichonlysomeofthemaresusceptible。Thefirsthavewrotelikecritics，thesecondlikegrammarians。
　　I。Thefirst，amongwhomwemaycountalltheancientmoralists，havecontentedthemselveswithdescribinginageneralmannerthedifferentvicesandvirtues，andwithpointingoutthedeformityandmiseryoftheonedispositionaswellastheproprietyandhappinessoftheother，buthavenotaffectedtolaydownmanypreciserulesthataretoholdgoodunexceptionablyinallparticularcases。Theyhaveonlyendeavouredtoascertain，asfaraslanguageiscapableofascertaining，first，whereinconsiststhesentimentoftheheart，uponwhicheachparticularvirtueisfounded，whatsortofinternalfeelingoremotionitiswhichconstitutestheessenceoffriendship，ofhumanity，ofgenerosity，ofjustice，ofmagnanimity，andofalltheothervirtues，aswellasoftheviceswhichareopposedtothem:and，secondly，whatisthegeneralwayofacting，theordinarytoneandtenorofconducttowhicheachofthosesentimentswoulddirectus，orhowitisthatafriendly，agenerous，abrave，ajust，andahumaneman，would，uponordinaryoccasions，chusetoact。
　　Tocharacterizethesentimentoftheheart，uponwhicheachparticularvirtueisfounded，thoughitrequiresbothadelicateandanaccuratepencil，isatask，however，whichmaybeexecutedwithsomedegreeofexactness。Itisimpossible，indeed，toexpressallthevariationswhicheachsentimenteitherdoesoroughttoundergo，accordingtoeverypossiblevariationofcircumstances。Theyareendless，andlanguagewantsnamestomarkthemby。Thesentimentoffriendship，forexample，whichwefeelforanoldmanisdifferentfromthatwhichwefeelforayoung:
　　thatwhichweentertainforanausteremandifferentfromthatwhichwefeelforoneofsofterandgentlermanners:andthatagainfromwhatwefeelforoneofgayvivacityandspirit。Thefriendshipwhichweconceiveforamanisdifferentfromthatwithwhichawomanaffectsus，evenwherethereisnomixtureofanygrosserpassion。Whatauthorcouldenumerateandascertaintheseandalltheotherinfinitevarietieswhichthissentimentiscapableofundergoing？Butstillthegeneralsentimentoffriendshipandfamiliarattachmentwhichiscommontothemall，maybeascertainedwithasufficientdegreeofaccuracy。Thepicturewhichisdrawnofit，thoughitwillalwaysbeinmanyrespectsincomplete，may，however，havesucharesemblanceastomakeusknowtheoriginalwhenwemeetwithit，andevendistinguishitfromothersentimentstowhichithasaconsiderableresemblance，suchasgood-will，respect，esteem，admiration。
　　Todescribe，inageneralmanner，whatistheordinarywayofactingtowhicheachvirtuewouldpromptus，isstillmoreeasy。
　　Itis，indeed，scarcepossibletodescribetheinternalsentimentoremotionuponwhichitisfounded，withoutdoingsomethingofthiskind。Itisimpossiblebylanguagetoexpress，ifImaysayso，theinvisiblefeaturesofallthedifferentmodificationsofpassionastheyshowthemselveswithin。Thereisnootherwayofmarkinganddistinguishingthemfromoneanother，butbydescribingtheeffectswhichtheyproducewithout，thealterationswhichtheyoccasioninthecountenance，intheairandeternalbehaviour，theresolutionstheysuggest，theactionstheypromptto。ItisthusthatCicero，inthefirstbookofhisOffices，endeavourstodirectustothepracticeofthefourcardinalvirtues，andthatAristotleinthepracticalpartsofhisEthics，pointsouttousthedifferenthabitsbywhichhewouldhaveusregulateourbehaviour，suchasliberality，magnificence，magnanimity，andevenjocularityandgood-humour，qualitieswhichthatindulgentphilosopherhasthoughtworthyofaplaceinthecatalogueofthevirtues，thoughthelightnessofthatapprobationwhichwenaturallybestowuponthem，shouldnotseemtoentitlethemtosovenerableaname。
　　Suchworkspresentuswithagreeableandlivelypicturesofmanners。Bythevivacityoftheirdescriptionstheyinflameournaturalloveofvirtue，andincreaseourabhorrenceofvice:bythejustnessaswellasdelicacyoftheirobservationstheymayoftenhelpbothtocorrectandtoascertainournaturalsentimentswithregardtotheproprietyofconduct，andsuggestingmanyniceanddelicateattentions，formustoamoreexactjustnessofbehaviour，thanwhat，withoutsuchinstruction，weshouldhavebeenapttothinkof。Intreatingoftherulesofmorality，inthismanner，consiststhesciencewhichisproperlycalledEthics，asciencewhich，thoughlikecriticismitdoesnotadmitofthemostaccurateprecision，is，however，bothhighlyusefulandagreeable。Itisofallothersthemostsusceptibleoftheembellishmentsofeloquence，andbymeansofthemofbestowing，ifthatbepossible，anewimportanceuponthesmallestrulesofduty。Itsprecepts，whenthusdressedandadorned，arecapableofproducingupontheflexibilityofyouth，thenoblestandmostlastingimpressions，andastheyfallinwiththenaturalmagnanimityofthatgenerousage，theyareabletoinspire，foratimeatleast，themostheroicresolutions，andthustendbothtoestablishandconfirmthebestandmostusefulhabitsofwhichthemindofmanissusceptible。Whateverpreceptandexhortationcandotoanimateustothepracticeofvirtue，isdonebythissciencedeliveredinthismanner。
　　II。Thesecondsetofmoralists，amongwhomwemaycountallthecasuistsofthemiddleandlatteragesofthechristianchurch，aswellasallthosewhointhisandintheprecedingcenturyhavetreatedofwhatiscallednaturaljurisprudence，donotcontentthemselveswithcharacterizinginthisgeneralmannerthattenorofconductwhichtheywouldrecommendtous，butendeavourtolaydownexactandpreciserulesforthedirectionofeverycircumstanceofourbehaviour。Asjusticeistheonlyvirtuewithregardtowhichsuchexactrulescanproperlybegiven；itisthisvirtue，thathaschieflyfallenundertheconsiderationofthosetwodifferentsetsofwriters。Theytreatofit，however，inaverydifferentmanner。
　　Thosewhowriteupontheprinciplesofjurisprudence，consideronlywhatthepersontowhomtheobligationisdue，oughttothinkhimselfentitledtoexactbyforce；whateveryimpartialspectatorwouldapproveofhimforexacting，orwhatajudgeorarbiter，towhomhehadsubmittedhiscase，andwhohadundertakentodohimjustice，oughttoobligetheotherpersontosufferortoperform。Thecasuists，ontheotherhand，donotsomuchexaminewhatitis，thatmightproperlybeexactedbyforce，aswhatitis，thatthepersonwhoowestheobligationoughttothinkhimselfboundtoperformfromthemostsacredandscrupulousregardtothegeneralrulesofjustice，andfromthemostconscientiousdread，eitherofwronginghisneighbour，orofviolatingtheintegrityofhisowncharacter。Itistheendofjurisprudencetoprescriberulesforthedecisionsofjudgesandarbiters。Itistheendofcasuistrytoprescriberulesfortheconductofagoodman。Byobservingalltherulesofjurisprudence，supposingthemeversoperfect，weshoulddeservenothingbuttobefreefromexternalpunishment。Byobservingthoseofcasuistry，supposingthemsuchastheyoughttobe，weshouldbeentitledtoconsiderablepraisebytheexactandscrupulousdelicacyofourbehaviour。
　　Itmayfrequentlyhappenthatagoodmanoughttothinkhimselfbound，fromasacredandconscientiousregardtothegeneralrulesofjustice，toperformmanythingswhichitwouldbethehighestinjusticetoextortfromhim，orforanyjudgeorarbitertoimposeuponhimbyforce。Togiveatriteexample；ahighwayman，bythefearofdeath，obligesatravellertopromisehimacertainsumofmoney。Whethersuchapromise，extortedinthismannerbyunjustforce，oughttoberegardedasobligatory，isaquestionthathasbeenverymuchdebated。
　　Ifweconsideritmerelyasaquestionofjurisprudence，thedecisioncanadmitofnodoubt。Itwouldbeabsurdtosupposethatthehighwaymancanbeentitledtouseforcetoconstraintheothertoperform。Toextortthepromisewasacrimewhichdeservedthehighestpunishment，andtoextorttheperformancewouldonlybeaddinganewcrimetotheformer。Hecancomplainofnoinjurywhohasbeenonlydeceivedbythepersonbywhomhemightjustlyhavebeenkilled。Tosupposethatajudgeoughttoenforcetheobligationofsuchpromises，orthatthemagistrateoughttoallowthemtosustainactionatlaw，wouldbethemostridiculousofallabsurdities。Ifweconsiderthisquestion，therefore，asaquestionofjurisprudence，wecanbeatnolossaboutthedecision。
　　Butifweconsideritasaquestionofcasuistry，itwillnotbesoeasilydetermined。Whetheragoodman，fromaconscientiousregardtothatmostsacredruleofjustice，whichcommandstheobservanceofallseriouspromises，wouldnotthinkhimselfboundtoperform，isatleastmuchmoredoubtful。Thatnoregardisduetothedisappointmentofthewretchwhobringshimintothissituation，thatnoinjuryisdonetotherobber，andconsequentlythatnothingcanbeextortedbyforce，willadmitofnosortofdispute。Butwhethersomeregardisnot，inthiscase，duetohisowndignityandhonour，totheinviolablesacrednessofthatpartofhischaracterwhichmakeshimreverencethelawoftruthandabhoreverythingthatapproachestotreacheryandfalsehood，may，perhaps，morereasonablybemadeaquestion。Thecasuistsaccordinglyaregreatlydividedaboutit。Oneparty，withwhomwemaycountCiceroamongtheancients，amongthemoderns，Puffendorf，Barbeyrachiscommentator，andaboveallthelateDrHutcheson，onewhoinmostcaseswasbynomeansaloosecasuist，determine，withoutanyhesitation，thatnosortofregardisduetoanysuchpromise，andthattothinkotherwiseismereweaknessandsuperstition。Anotherparty，amongwhomwemayreckon20*someoftheancientfathersofthechurch，aswellassomeveryeminentmoderncasuists，havebeenofanotheropinion，andhavejudgedallsuchpromisesobligatory。
　　Ifweconsiderthematteraccordingtothecommonsentimentsofmankind，weshallfindthatsomeregardwouldbethoughtdueeventoapromiseofthiskind；butthatitisimpossibletodeterminehowmuch，byanygeneralrulethatwillapplytoallcaseswithoutexception。Themanwhowasquitefrankandeasyinmakingpromisesofthiskind，andwhoviolatedthemwithaslittleceremony，weshouldnotchuseforourfriendandcompanion。Agentlemanwhoshouldpromiseahighwaymanfivepoundsandnotperform，wouldincursomeblame。Ifthesumpromised，however，wasverygreat，itmightbemoredoubtful，whatwaspropertobedone。Ifitwassuch，forexample，thatthepaymentofitwouldentirelyruinthefamilyofthepromiser，ifitwassogreatastobesufficientforpromotingthemostusefulpurposes，itwouldappearinsomemeasurecriminal，atleastextremelyimproper，tothrowit，forthesakeofapunctilio，intosuchworthlesshands。Themanwhoshouldbeggarhimself，orwhoshouldthrowawayanhundredthousandpounds，thoughhecouldaffordthatvastsum，forthesakeofobservingsuchaparolewithathief，wouldappeartothecommonsenseofmankind，absurdandextravagantinthehighestdegree。Suchprofusionwouldseeminconsistentwithhisduty，withwhatheowedbothtohimselfandothers，andwhat，therefore，regardtoapromiseextortedinthismanner，couldbynomeansauthorise。Tofix，however，byanypreciserule，whatdegreeofregardoughttobepaidtoit，orwhatmightbethegreatestsumwhichcouldbeduefromit，isevidentlyimpossible。Thiswouldvaryaccordingtothecharactersofthepersons，accordingtotheircircumstances，accordingtothesolemnityofthepromise，andevenaccordingtotheincidentsoftherencounter。andifthepromiserhadbeentreatedwithagreatdealofthatsortofgallantry，whichissometimestobemetwithinpersonsofthemostabandonedcharacters，morewouldseemduethanuponotheroccasions。Itmaybesaidingeneral，thatexactproprietyrequirestheobservanceofallsuchpromises，whereveritisnotinconsistentwithsomeotherdutiesthataremoresacred；suchasregardtothepublicinterest，tothosewhomgratitude，whomnaturalaffection，orwhomthelawsofproperbeneficenceshouldpromptustoprovidefor。But，aswasformerlytakennoticeof，wehavenopreciserulestodeterminewhatexternalactionsareduefromaregardtosuchmotives，nor，consequently，whenitisthatthosevirtuesareinconsistentwiththeobservanceofsuchpromises。