the origin and nature of emotions-第8节

按键盘上方向键 ← 或 → 可快速上下翻页，按键盘上的 Enter 键可回到本书目录页，按键盘上方向键 ↑ 可回到本页顶部！
————未阅读完？加入书签已便下次继续阅读！




Natural　Selection　and　Chemical　Noci…association　in　the　Infections


Thus　far　we　have　considered　the　behavior　of　the　individual　as　a　whole　in　his　response　to　a　certain　type　of　noci…influences。　We　have　been　voicing　our　argument　in　terms　of　physical　escape　from　GROSS　physical　dangers；　or　of　grappling　with　GROSS　NERVE…MUSCULAR　enemies　of　the　same　or　of　other　species。　　To　explain　these　phenomena　we　have　invoked　the　aid　of　the　laws　of　natural　selection　and　phylogenetic　association。　If　our　conclusions　be　correct；　then　it　should　follow　that　in　the　same　laws　we　may　find　the　explanation　of　immunity；　which；　of　course；　means　a　defensive　response　to　our　MICROSCOPIC　enemies。　　There　should　be　no　more　difficulty　in　evolving　an　efficient　army　of　phagocytes　by　natural　selection；　or　in　developing　specific　chemical　reactions　against　_*microscopic　enemies_；　than　there　was　in　evolving　the　various　nociceptors　for　our　nerve…muscular　defense　against　our　_*gross　enemies_。　That　immunity　is　a　chemical　reaction　is　no　argument　against　the　application　of　the　law　of　natural　selection　or　of　association。　What　essential　difference　is　there　between　the　chemical　defense　of　the　skunk　against　its　NERVE…MUSCULAR　enemies　and　its　chemical　defense　（immunity）　against　its　MICROSCOPIC　ENEMIES？

The　administration　of　vaccines　becomes　the　adequate　stimulus　which　awakens　phylogenetic　association　of　a　chemical　nature　as　a　result　of　which　immune　bodies　are　produced。

In　discussing　this　subject　I　will　raise　only　the　question　whether　or　not　the　specific　character　of　the　inaugural　symptoms　of　some　infectious　diseases　may　be　due　to　phylogenetic　association。　These　inaugural　symptoms　are　measurably　a　recapitulation　of　the　leading　phenomena　of　the　disease　in　its　completed　clinical　picture。　Thus；　the　furious　initiative　symptoms　of　pneumonia；　of　peritonitis；　or　erysipelas；　of　the　exanthemata；　are　exaggerations　of　phenomena　which　are　analogous　to　the　phenomena　accompanying　physical　injury　and　fear　of　physical　violence。　　Just　as　the　acute　phenomena　of　fear；　or　those　which　accompany　the　adequate　stimulation　of　nociceptors；　are　recapitulations　of　phylogenetic　struggles；　so　may　the　inaugural　symptoms　of　an　infection　be　a　similar　phylogenetic　recapitulation　of　the　course　of　the　disease。　　A　certain　amount　of　negative　evidence　is　supplied　by　a　comparison　of　the　response　to　a　dose　of　toxins　with　the　response　to　a　dose　of　a　standard　drug。　No　drug　in　therapeutic　dosage　except　the　iodin　compounds　causes　a　febrile　response；　no　drug　causes　a　chill；　on　the　other　hand；　all　specific　toxins　cause　febrile　responses　and　many　cause　chills。　If　a　species　of　animal　had　been　poisoned　by　a　drug　during　vast　periods　of　time；　and　if　natural　selection　had　successfully　established　a　self…defensive　response；　then　the　administration　of　that　drug　would　cause　a　noci…association　（chemical）；　and　a　specific　reaction　analogous　to　that　following　the　administration　of　Coley's　toxins　might　be　expected。　Bacterial　noci…association　probably　operates　through　the　same　law　as　that　through　which　physical　noci…association　operates。　Natural　selection　is　impartial；　however。　　It　must　be　supposed　that　it　acts　impartially　upon　the　microscopic　invader　and　upon　the　host。　On　this　ground　one　must　infer　that；　in　accordance　with　the　same　law　of　natural　selection；　the　bacteria　of　acute　infections　have　met　by　natural　selection　each　advance　in　the　struggle　of　the　host　for　immunity。　　Hence　the　fast　and　furious　struggle　between　man　and　his　microscopic　enemies　merely　indicates　to　what　extent　natural　selection　has　developed　the　ATTACK　and　the　DEFENSE　respectively。　This　struggle　is　analogous　to　the　quick　and　decisive　battles　of　the　carnivora　when　fighting　among　themselves　or　when　contending　against　their　ancient　enemies。　　But　when　phylogenetically　strange　animals　meet　each　other；　they　do　not　understand　how　to　conduct　a　fight：　natural　selection　has　not　had　the　opportunity　of　teaching　them。　The　acute　infections　have　the　characteristics　of　being　ancient　enemies。　On　this　hypothesis　one　can　understand　the　high　mortality　of　measles　when　it　is　introduced　into　a　new　country。　　By　natural　selection；　measles　has　become　a　powerful　enemy　of　the　human　race；　and　a　race　to　which　this　infection　is　newly　introduced　has　not　had　the　advantage　of　building　up　a　defense　against　it　by　the　law　of　natural　selection。　May　not　the　phenomena　of　anaphylaxis　be　studied　on　associational　lines？　Then；　too；　there　may　be　chemical　noci…associations　with　enemies　now　extinct；　which；　like　the　ticklish　points；　may　still　be　active　on　adequate　stimulation。　　This　brief　reference　to　the　possible　relation　of　the　phenomena　of　the　acute　infections　to　the　laws　of　natural　selection　and　of　specific　chemical　noci…association　has　been　made　as　a　suggestion。　　Since　the　doctrine　of　evolution　explains　all　or　nothing；　I　have　included　many　phenomena　to　see　how　reasonable　or　unreasonable　such　an　explanation　might　be。


Recapitulation


The　following　are　the　principal　points　presented：　　In　operations　under　inhalation　anesthesia　the　nerve　impulses　from　the　trauma　reach　every　part　of　the　brainthe　cerebrum　that　is　apparently　anesthetized　as　well　as　the　medulla　that　is　known　to　remain　awake　the　proof　being　the　PHYSIOLOGIC　exhaustion　of　and　the　PATHOLOGIC　change　in　the　nerve…cells。　Under　ether　anesthesia　the　damage　to　the　nerve…cells　is　at　least　four　times　greater　than　under　nitrous　oxid。　　Inhalation　anesthesia　is；　therefore；　but　a　veneer　a　mask　that　〃covers　the　deep　suffering　of　the　patient。〃　　The　cause　of　the　exhaustion　of　the　brain　is　the　discharge　of　nervous　energy　in　a　futile　effort　to　energize　the　paralyzed　muscles　in　an　attempt　to　escape　from　the　injury　just　as　if　no　anesthetic　had　been　given。　The　exhaustion　is；　therefore；　of　the　same　nature　as　that　from　overexertion；　but　if　the　nerve…paths　connecting　the　field　of　operation　and　the　brain　be　blocked；　then　there　is　no　discharge　of　nervous　energy　from　the　trauma；　and　consequently　there　is　no　exhaustion；　however　severe　or　prolonged　the　operation　may　be。

Fear　is　a　factor　in　many　injuries　and　operations。　　The　phenomena　of　fear　probably　are　exhibited　only　by　animals　whose　natural　defense　is　nerve…muscular。　The　skunk；　the　porcupine；　the　turtle；　have　little　or　no　fear。　　Fear　is　born　of　the　innumerable　injuries　which　have　been　inflicted　in　the　course　of　evolution。　　Fear；　like　trauma；　may　cause　physiologic　exhaustion　of　and　morphologic　changes　in　the　brain…cells。　The　representation　of　injury；　which　is　fear；　being　elicited　by　phylogenetic　association；　may　be　prevented　by　the　exclusion　of　the　noci…association　or　by　the　administration　of　drugs　like　morphin　and　scopolamin；　which　so　impair　the　associational　function　of　the　brain…cells　that　immunity　to　fear　is　established。　Animals　whose　natural　defense　is　in　muscular　exertion；　among　which　is　man；　may　have　their　dischargeable　nervous　energy　exhausted　by　fear　alone；　or　by　trauma　alone；　but　most　effectively　by　the　combination　of　both。　What　is　the　mechanism　of　this　discharge　of　energy？　　It　is　the　adequate　stimulation　of　the　nociceptors　and　the　physiologic　response　for　the　purpose　of　self…preservation。　According　to　Sherrington；　the　nervous　system　responds　in　action　as　a　whole　and　to　but　one　stimulus　at　a　time。　The　integration　of　the　individual　as　a　whole　occurs　not　alone　in　injury　and　fear；　but　also；　though　not　so　markedly；　as　a　result　of　other　phylogenetic　associations；　such　as　those　of　the　chase　and　procreation。　When　adequate　stimuli　are　repeated　with　such　rapidity　that　the　new　stimulus　is　received　before　the　effect　of　the　previous　one　has　worn　off；　a　higher　maximum　effect　is　produced　than　is　possible　under　a　single　stimulus；　however　powerful。

Sexual　receptors　are　implanted　in　the　body　by　natural　selection；　and　the　adequate　stimuli　excite　the　nerve…muscular　reactions　of　conjugation　in　a　manner　analogous　to　the　action　of　the　adequate　stimuli　of　the　nociceptors。　　The　specific　response　of　either　the　sexual　receptors　or　the　nociceptors　is　at　the　expense　of　the　total　amount　of　nervous　energy　available　at　the　moment。　Likewise　in　daily　labor；　which；　in　the　language　of　evolution；　is　the　chase；　nervous　energy　is　expended。　　Under　the　dominance　of　fear　or　injury；　however；　the　integration　is　most　nearly　absolute　and　probably　every　expenditure　of　nervous　energy　which　is　not　required　for　efforts　toward　self…preservation　is　arrested；　hence　fear　and　injury　drain　the　cup　of　energy　to　the　dregs。　This　is　the　potential　difference　between　fear　and　desire；　between　injury　and　conjugation。

What　is　the　practical　application　of　this？　　In　operative　surgery　there　is　introduced　a　new　principle；　which　removes　from　surgery　much　of　the　immediate　risk　from　its　trauma　by　establishing　ANOCI…ASSOCIATION；　it　places　certain　of　the　phenomena　of　fear　on　a　physical　basis；　it　explains　to　us　the　physical　basis　for　the　impairment　of　the　entire　individual　under　worry　or　misfortune；　it　makes　evident　the　physical　results　of　the　daily　noci…associations　experienced　by　the　individual　as　a　social　unit。　　On　the　other　hand；　it　explains　the　power　of　therapeutic　suggestion　and　of　other　influences　which　serve　for　the　time　to　change　the　noci…integration；　it　shows　the　physical　basis　for　the　difference　between　hope　and　despair；　it　explains　some　of　the　phenomena　of　Graves'　dis