Nowwhetheritbesoornot，canonlyappearuponexamination；anditisincumbentonthesephilosopherstomakegoodtheirassertion，bydefiningordescribingthatnecessity，andpointingitouttousintheoperationsofmaterialcauses。
Itwouldseem，indeed，thatmenbeginatthewrongendofthisquestionconcerninglibertyandnecessity，whentheyenteruponitbyexaminingthefacultiesofthesoul，theinfluenceoftheunderstanding，andtheoperationsofthewill。Letthemfirstdiscussamoresimplequestion，namely，theoperationsofbodyandofbruteunintelligentmatter；
andtrywhethertheycanthereformanyideaofcausationandnecessity，exceptthatofaconstantconjunctionofobjects，andsubsequentinferenceofthemindfromonetoanother。Ifthesecircumstancesform，inreality，thewholeofthatnecessity，whichweconceiveinmatter，andifthesecircumstancesbealsouniversallyacknowledgedto
takeplaceintheoperationsofthemind，thedisputeisatanend；atleast，mustbeownedtobethenceforthmerelyverbal。Butaslongaswewillrashlysuppose，thatwehavesomefartherideaofnecessityandcausationintheoperationsofexternalobjects；atthesametime，thatwecanfindnothingfartherinthevoluntaryactionsofthemind；thereisnopossibilityofbringingthequestiontoanydeterminateissue，whileweproceeduponsoerroneousasupposition。Theonlymethodofundeceivingusistomountuphigher；toexaminethenarrowextentofsciencewhenappliedtomaterialcauses；andtoconvinceourselvesthatallweknowofthemistheconstantconjunctionandinferenceabovementioned。Wemay，perhaps，findthatitiswithdifficultyweareinducedtofixsuchnarrowlimitstohumanunderstanding:Butwecanafterwardsfindnodifficultywhenwecometoapplythisdoctrinetotheactionsofthewill。
Forasitisevidentthatthesehavearegularconjunctionwithmotivesandcircumstancesandcharacters，andaswealwaysdrawinferencesfromonetotheother，wemustbeobligedtoacknowledgeinwordsthatnecessity，whichwehavealreadyavowed，ineverydeliberationofourlives，andineverystepofourconductandbehaviour。[22]