I　have　just　spoken　of；　and　there　is　therefore　nothing　in　them　which　does　not　give　testimony　to　the　power　and　goodness　of　the　God　＇who　has　produced　them28＇。　　Thus；　for　example；　when　the　nerves　which　are　in　the　feet　are　violently　or　more　than　usually　moved；　their　movement；　passing　through　the　medulla　of　the　spine29　to　the　inmost　parts　of　the　brain；　gives　a　sign　to　the　mind　which　makes　it　feel　somewhat；　to　wit；　pain；　as　though　in　the　foot；　by　which　the　mind　is　excited　to　do　its　utmost　to　remove　the　cause　of　the　evil　as　dangerous　and　hurtful　to　the　foot。　　It　is　true　that　God　could　have　constituted　the　nature　of　man　in　such　a　way　that　this　same　movement　in　the　brain　would　have　conveyed　something　quite　different　to　the　mind；　for　example；　it　might　have　produced　consciousness　of　itself　either　in　so　far　as　it　is　in　the　brain；　or　as　it　is　in　the　foot；　or　as　it　is　in　some　other　place　between　the　foot　and　the　brain；　or　it　might　finally　have　produced　consciousness　of　anything　else　whatsoever；　but　none　of　all　this　would　have　contributed　so　well　to　the　conservation　of　the　body。　　Similarly；　when　we　desire　to　drink；　a　certain　dryness　of　the　throat　is　produced　which　moves　its　nerves；　and　by　their　means　the　internal　portions　of　the　brain；　and　this　movement　causes　in　the　mind　the　sensation　of　thirst；　because　in　this　case　there　is　nothing　more　useful　to　us　than　to　become　aware　that　we　have　need　to　drink　for　the　conservation　o　our　health；　and　the　same　holds　good　in　other　instances。　　　　　　From　this　it　is　quite　clear　that；　notwithstanding　the　supreme　goodness　of　God；　the　nature　of　man；　inasmuch　as　it　is　composed　of　mind　and　body；　cannot　be　otherwise　than　sometimes　a　source　of　deception。　　For　if　there　is　any　cause　which　excites；　not　in　the　foot　but　in　some　part　of　the　nerves　which　are　extended　between　the　foot　and　the　brain；　or　even　in　the　brain　itself；　the　same　movement　which　usually　is　produced　when　the　foot　is　detrimentally　affected；　pain　will　be　experienced　as　though　it　were　in　the　foot；　and　the　sense　will　thus　naturally　be　deceived；　for　since　the　same　movement　in　the　brain　is　capable　of　causing　but　one　sensation　in　the　mind；　and　this　sensation　is　much　more　frequently　excited　by　a　cause　which　hurts　the　foot　than　by　another　existing　in　some　other　quarter；　it　is　reasonable　that　it　should　convey　to　the　mind　pain　in　the　foot　rather　than　in　any　other　part　of　the　body。　And　although　the　parchedness　of　the　throat　does　not　always　proceed；　as　it　usually　does；　from　the　fact　that　drinking　is　necessary　for　the　health　of　the　body；　but　sometimes　comes　from　quite　a　different　cause；　as　is　the　case　with　dropsical　patients；　it　is　yet　much　better　that　it　should　mislead　on　this　occasion　than　if；　on　the　other　hand；　it　were　always　to　deceive　us　when　the　body　is　in　good　health；　and　so　on　in　similar　cases。　　　　　　And　certainly　this　consideration　is　of　great　service　to　me；　not　only　in　enabling　me　to　recognise　all　the　errors　to　which　my　nature　is　subject；　but　also　in　enabling　me　to　avoid　them　or　to　correct　them　more　easily。　　for　knowing　that　all　my　senses　more　frequently　indicate　to　me　truth　than　falsehood　respecting　the　things　which　concern　that　which　is　beneficial　to　the　body；　and　being　able　almost　always　to　avail　myself　of　many　of　them　in　order　to　examine　one　particular　thing；　and；　besides　that；　being　able　to　make　use　of　my　memory　in　order　to　connect　the　present　with　the　past；　and　of　my　understanding　which　already　has　discovered　all　the　causes　of　my　errors；　I　ought　no　longer　to　fear　that　falsity　may　be　found　in　matters　every　day　presented　to　me　by　my　senses。　　And　I　ought　to　set　aside　all　the　doubts　of　these　past　days　as　hyperbolical　and　ridiculous；　particularly　that　very　common　uncertainty　respecting　sleep；　which　I　could　not　distinguish　from　the　waking　state；　for　at　present　I　find　a　very　notable　difference　between　the　two；　inasmuch　as　our　memory　can　never　connect　our　dreams　one　with　the　other；　or　with　the　whole　course　of　our　lives；　as　it　unites　events　which　happen　to　us　while　we　are　awake。　　And；　as　a　matter　of　fact；　if　someone；　while　I　was　awake；　quite　suddenly　appeared　to　me　and　disappeared　as　fast　as　do　the　images　which　I　see　in　sleep；　so　that　I　could　not　know　from　whence　the　form　came　nor　whither　it　went；　it　would　not　be　without　reason　that　I　should　deem　it　a　spectre　or　a　phantom　formed　by　my　brain　＇and　similar　to　those　which　I　form　in　sleep＇；　rather　than　a　real　man。　　But　when　I　perceive　things　as　to　which　I　know　distinctly　both　the　place　from　which　they　proceed；　and　that　in　which　they　are；　and　the　time　at　which　they　appeared　to　me；　and　when；　without　any　interruption；　I　can　connect　the　perceptions　which　I　have　of　them　with　the　whole　course　of　my　life；　I　am　perfectly　assured　that　these　perceptions　occur　while　I　am　waking　and　not　during　sleep。　　And　I　ought　in　no　wise　to　doubt　the　truth　of　such　matters；　if；　after　having　called　up　all　my　senses；　my　memory；　and　my　understanding；　to　examine　them；　nothing　is　brought　to　evidence　by　any　one　of　them　which　is　repugnant　to　what　is　set　forth　by　the　others。　　For　because　God　is　in　no　wise　a　deceiver；　it　follows　that　I　am　not　deceived　in　this。　　But　because　the　exigencies　of　action　often　oblige　us　to　make　up　our　minds　before　having　leisure　to　examine　matters　carefully；　we　must　confess　that　the　life　of　man　is　very　frequently　subject　to　error　in　respect　to　individual　objects；　and　we　must　in　the　end　acknowledge　the　infirmity　of　our　nature。
  Notes：
  2For　convenience　sake　the　〃Objections　and　Replies〃　are　published　in　the　second　volume　of　this　edition。　3The　French　version　is　followed　here。　4The　French　version　is　followed　here。　5When　it　is　thought　desirable　to　insert　additional　readings　from　the　French　version　this　will　be　indicated　by　the　use　of　square　brackets。　6Between　the　Praefatio　ad　Lectorem　and　the　Synopsis；　the　Paris　Edition　（1st　Edition）　interpolates　an　Index　which　is　not　found　in　the　Amsterdam　Edition　（2nd　Edition）。　　Since　Descartes　did　not　reproduce　it；　he　was　doubtless　not　its　author。　　Mersenne　probably　composed　it　himself；　adjusting　it　to　the　paging　of　the　first　Edition。　（Note　in　Adam　and　Tannery's　Edition。）　7intellectio。　8imaginatio。　9In　place　of　this　long　title　at　the　head　of　the　page　the　first　Edition　had　immediately　after　the　Synopsis；　and　on　the　same　page　7；　simply　〃First　Meditation。〃　　（Adam's　Edition。）　10Or　〃form　an　image〃　（effingo）。　11Sentire。　12entendement　F。；　mens　L。　13inspectio。　14sensus　communis。　15Percipio；　F。　nous　concevons。　16The　French　version　is　followed　here　as　being　more　explicit。　In　it　〃action　de　mon　esprit〃　replaces　〃mea　cogitatio。〃　17In　the　Latin　version　〃similitudinem。〃　18Not　in　the　French　version。　19percipio。　20perceptio。　21〃In　the　idea　of　whom　alone　necessary　or　eternal　existence　is　comprised。〃　　French　version。　22〃From　the　moment　that。〃　　French　version。　23〃Conception；〃　French　version。　　〃intellectionem；〃　Latin　version。　24intueor。　25acie　mentis。　26intellectionem。　27sensus　communis。　28Latin　version　only。　29spini　dorsae　medullam。