ChapterXII
OftheImprovementofourKnowledge1。Knowledgeisnotgotfrommaxims。Ithavingbeenthecommonreceivedopinionamongstmenofletters，thatmaximswerethefoundationofallknowledge；andthatthescienceswereeachofthembuiltuponcertainpraecognitafromwhencetheunderstandingwastotakeitsrise，andbywhichitwastoconductitselfinitsinquiriesintothemattersbelongingtothatscience，thebeatenroadoftheSchoolshasbeen，tolaydowninthebeginningoneormoregeneralpropositions，asfoundationswhereontobuildtheknowledgethatwastobehadofthatsubject。Thesedoctrines，thuslaiddownforfoundationsofanyscience，werecalledprinciples，asthebeginningsfromwhichwemustsetout，andlooknofurtherbackwardsinourinquiries，aswehavealreadyobserved。
2。Theoccasionofthatopinion。Onethingwhichmightprobablygiveanoccasiontothiswayofproceedinginothersciences，wasasIsupposethegoodsuccessitseemedtohaveinmathematics，whereinmen，beingobservedtoattainagreatcertaintyofknowledge，thesesciencescamebypre-eminencetobecalledMathemata，andMathesis，learning，orthingslearned，thoroughlylearned，ashavingofallothersthegreatestcertainty，clearness，andevidenceinthem。
3。Butfromcomparingclearanddistinctideas。Butifanyonewillconsider，hewillIguessfind，thatthegreatadvancementandcertaintyofrealknowledgewhichmenarrivedtointhesesciences，wasnotowingtotheinfluenceoftheseprinciples，norderivedfromanypeculiaradvantagetheyreceivedfromtwoorthreegeneralmaxims，laiddowninthebeginning；butfromtheclear，distinct，completeideastheirthoughtswereemployedabout，andtherelationofequalityandexcesssoclearbetweensomeofthem，thattheyhadanintuitiveknowledge，andbythatawaytodiscoveritinothers；andthiswithoutthehelpofthosemaxims。ForIask，Isitnotpossibleforayoungladtoknowthathiswholebodyisbiggerthanhislittlefinger，butbyvirtueofthisaxiom，thatthewholeisbiggerthanapart；norbeassuredofit，tillhehaslearnedthatmaxim？Orcannotacountrywenchknowthat，havingreceivedashillingfromonethatowesherthree，andashillingalsofromanotherthatowesherthree，theremainingdebtsineachoftheirhandsareequal？Cannotsheknowthis，Isay，unlessshefetchthecertaintyofitfromthismaxim，thatifyoutakeequalsfromequals，theremainderwillbeequals，amaximwhichpossiblysheneverheardorthoughtof？Idesireanyonetoconsider，fromwhathasbeenelsewheresaid，whichisknownfirstandclearestbymostpeople，theparticularinstance，orthegeneralrule；andwhichitisthatgiveslifeandbirthtotheother。Thesegeneralrulesarebutthecomparingourmoregeneralandabstractideas，whicharetheworkmanshipofthemind，made，andnamesgiventothemfortheeasierdispatchinitsreasonings，anddrawingintocomprehensivetermsandshortrulesitsvariousandmultipliedobservations。Butknowledgebeganinthemind，andwasfoundedonparticulars；thoughafterwards，perhaps，nonoticewastakenthereof:itbeingnaturalforthemindforwardstilltoenlargeitsknowledgemostattentivelytolayupthosegeneralnotions，andmaketheproperuseofthem，whichistodisburdenthememoryofthecumbersomeloadofparticulars。ForIdesireitmaybeconsidered，whatmorecertaintythereistoachild，oranyone，thathisbody，littlefinger，andall，isbiggerthanhislittlefingeralone，afteryouhavegiventohisbodythenamewhole，andtohislittlefingerthenamepart，thanhecouldhavehadbefore；
orwhatnewknowledgeconcerninghisbodycanthesetworelativetermsgivehim，whichhecouldnothavewithoutthem？Couldhenotknowthathisbodywasbiggerthanhislittlefinger，ifhislanguagewereyetsoimperfectthathehadnosuchrelativetermsaswholeandpart？I