an enquiry concerning human understanding-第9节

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the　branches　of　human　knowledge；　endeavour　to　show　that　none
of　them　can　afford　such　an　argument。

　　　　　All　reasonings　may　be　divided　into　two　kinds；　namely；
demonstrative　reasoning；　or　that　concerning　relations　of
ideas；　and　moral　reasoning；　or　that　concerning　matter　of
fact　and　existence。　That　there　are　no　demonstrative
arguments　in　the　case　seems　evident；　since　it　implies　no
contradiction　that　the　course　of　nature　may　change；　and　that
an　object；　seemingly　like　those　which　we　have　experienced；
may　be　attended　with　different　or　contrary　effects。　May　I
not　clearly　and　distinctly　conceive　that　a　body；　falling
from　the　clouds；　and　which；　in　all　other　respects；　resembles
snow；　has　yet　the　taste　of　salt　or　feeling　of　fire？　Is　there
any　more　intelligible　proposition　than　to　affirm；　that　all
the　trees　will　flourish　in　D/ECEMBER　and　J/ANUARY；　and
decay　in　M/AY　and　J/UNE？　Now　whatever　is　intelligible；　and
can　be　distinctly　conceived；　implies　no　contradiction；　and
can　never　be　proved　false　by　any　demonstrative　argument　or
abstract　reasoning　。

　　　　　If　we　be；　therefore；　engaged　by　arguments　to　put　trust
in　past　experience；　and　make　it　the　standard　of　our　future
judgment；　these　arguments　must　be　probable　only；　or　such　as
regard　matter　of　fact　and　real　existence　according　to　the
division　above　mentioned。　But　that　there　is　no　argument　of
this　kind；　must　appear；　if　our　explication　of　that　species
of　reasoning　be　admitted　as　solid　and　satisfactory。　We　have
said　that　all　arguments　concerning　existence　are　founded　on
the　relation　of　cause　and　effect；　that　our　knowledge　of　that
relation　is　derived　entirely　from　experience；　and　that　all
our　experimental　conclusions　proceed　upon　the　supposition
that　the　future　will　be　conformable　to　the　past。　To
endeavour；　therefore；　the　proof　of　this　last　supposition　by
probable　arguments；　or　arguments　regarding　existence；　must
be　evidently　going　in　a　circle；　and　taking　that　for　granted；
which　is　the　very　point　in　question。

　　　　　In　reality；　all　arguments　from　experience　are　founded
on　the　similarity　which　we　discover　among　natural　objects；
and　by　which　we　are　induced　to　expect　effects　similar　to
those　which　we　have　found　to　follow　from　such　objects。　And
though　none　but　a　fool　or　madman　will　ever　pretend　to
dispute　the　authority　of　experience；　or　to　reject　that　great
guide　of　human　life；　it　may　surely　be　allowed　a　philosopher
to　have　so　much　curiosity　at　least　as　to　examine　the
principle　of　human　nature；　which　gives　this　mighty　authority
to　experience；　and　makes　us　draw　advantage　from　that
similarity　which　nature　has　placed　among　different　objects。
From　causes　which；　appear　；　we　expect　similar
effects。　This　is　the　sum　of　all　our　experimental
conclusions。　Now　it　seems　evident　that；　if　this　conclusion
were　formed　by　reason；　it　would　be　as　perfect　at　first；　and
upon　one　instance；　as　after　ever　so　long　a　course　of
experience。　But　the　case　is　far　otherwise。　Nothing　so　like
as　eggs；　yet　no　one；　on　account　of　this　appearing
similarity；　expects　the　same　taste　and　relish　in　all　of
them。　It　is　only　after　a　long　course　of　uniform　experiments
in　any　kind；　that　we　attain　a　firm　reliance　and　security
with　regard　to　a　particular　event。　Now　where　is　that　process
of　reasoning　which；　from　one　instance；　draws　a　conclusion；
so　different　from　that　which　it　infers　from　a　hundred
instances　that　are　nowise　different　from　that　single　one？
This　question　I　propose　as　much　for　the　sake　of　information；
as　with　an　intention　of　raising　difficulties。　I　cannot　find；
I　cannot　imagine　any　such　reasoning。　But　I　keep　my　mind
still　open　to　instruction；　if　any　one　will　vouchsafe　to
bestow　it　on　me。

　　　　　Should　it　be　said　that；　from　a　number　of　uniform
experiments；　we　　a　connexion　between　the　sensible
qualities　and　the　secret　powers；　this；　I　must　confess；　seems
the　same　difficulty；　couched　in　different　terms。　The
question　still　recurs；　on　what　process　of　argument　this
　is　founded？　Where　is　the　medium；　the　interposing
ideas；　which　join　propositions　so　very　wide　of　each　other？
It　is　confessed　that　the　colour；　consistence；　and　other
sensible　qualities　of　bread　appear　not；　of　themselves；　to
have　any　connexion　with　the　secret　powers　of　nourishment　and
support。　For　otherwise　we　could　infer　these　secret　powers
from　the　first　appearance　of　these　sensible　qualities；
without　the　aid　of　experience；　contrary　to　the　sentiment　of
all　philosophers；　and　contrary　to　plain　matter　of　fact。
Here；　then；　is　our　natural　state　of　ignorance　with　regard　to
the　powers　and　influence　of　all　objects。　How　is　this
remedied　by　experience？　It　only　shows　us　a　number　of　uniform
effects；　resulting　from　certain　objects；　and　teaches　us　that
those　particular　objects；　at　that　particular　time；　were
endowed　with　such　powers　and　forces。　When　a　new　object；
endowed　with　similar　sensible　qualities；　is　produced；　we
expect　similar　powers　and　forces；　and　look　for　a　like
effect。　From　a　body　of　like　colour　and　consistence　with
bread　we　expect　like　nourishment　and　support。　But　this
surely　is　a　step　or　progress　of　the　mind；　which　wants　to　be
explained。　When　a　man　says；　　And　when　he　says；　；　he　is　not　guilty　of　a　tautology；　nor　are　these
propositions　in　any　respect　the　same。　You　say　that　the　one
proposition　is　an　inference　from　the　other。　But　you　must
confess　that　the　inference　is　not　intuitive；　neither　is　it
demonstrative：　Of　what　nature　is　it；　then？　To　say　it　is
experimental；　is　begging　the　question。　For　all　inferences
from　experience　suppose；　as　their　foundation；　that　the
future　will　resemble　the　past；　and　that　similar　powers　will
be　conjoined　with　similar　sensible　qualities。　If　there　be
any　suspicion　that　the　course　of　nature　may　change；　and　that
the　past　may　be　no　rule　for　the　future；　all　experience
becomes　useless；　and　can　give　rise　to　no　inference　or
conclusion。　It　is　impossible；　therefore；　that　any　arguments
from　experience　can　prove　this　resemblance　of　the　past　to
the　future；　since　all　these　arguments　are　founded　on　the
supposition　of　that　resemblance。　Let　the　course　of　things　be
allowed　hitherto　ever　so　regular；　that　alone；　without　some
new　argument　or　inference；　proves　not　that；　for　the　future；
it　will　continue　so。　In　vain　do　you　pretend　to　have　learned
the　nature　of　bodies　from　your　past　experience。　Their　secret
nature；　and　consequently　all　their　effects　and　influence；
may　change；　without　any　change　in　their　sensible　qualities。
This　happens　sometimes；　and　with　regard　to　some　objects：　Why
may　it　not　happen　always；　and　with　regard　to　all　objects？
What　logic；　what　process　or　argument　secures　you　against
this　supposition？　My　practice；　you　say；　refutes　my　doubts。
But　you　mistake　the　purport　of　my　question。　As　an　agent；　I
am　quite　satisfied　in　the　point；　but　as　a　philosopher；　who
has　some　share　of　curiosity；　I　will　not　say　scepticism；　I
want　to　learn　the　foundation　of　this　inference。　No　reading；
no　enquiry　has　yet　been　able　to　remove　my　difficulty；　or
give　me　satisfaction　in　a　matter　of　such　importance。　Can　I
do　better　than　propose　the　difficulty　to　the　public；　even
though；　perhaps；　I　have　small　hopes　of　obtaining　a　solution？
We　shall　at　least；　by　this　means；　be　sensible　of　our
ignorance；　if　we　do　not　augment　our　knowledge。

　　　　　I　must　confess　that　a　man　is　guilty　of　unpardonable
arrogance　who　concludes；　because　an　argument　has　escaped　his
own　investigation；　that　therefore　it　does　not　really　exist。
I　must　also　confess　that；　though　all　the　learned；　for
several　ages；　should　have　employed　themselves　in　fruitless
search　upon　any　subject；　it　may　still；　perhaps；　be　rash　to
conclude　positively　that　the　subject　must；　therefore；　pass
all　human　comprehension。　Even　though　we　examine　all　the
sources　of　our　knowledge；　and　conclude　them　unfit　for　such　a
subject；　there　may　still　remain　a　suspicion；　that　the
enumeration　is　not　complete；　or　the　examination　not
accurate。　But　with　regard　to　the　present　subject；　there　are
some　considerations　which　seem　to　remove　all　this　accusation
of　arrogance　or　suspicion　of　mistake。

　　　　　It　is　certain　that　the　most　ignorant　and　stupid
peasants　　nay　infants；　nay　even　brute　beasts　　improve　by
experience；　and　learn　the　qualities　of　natural　objects；　by
observing　the　effects　which　result　from　them。　When　a　child
has　felt　the　sensation　of　pain　from　touching　the　flame　of　a
candle；　he　will　be　careful　not　to　put　his　hand　near　any
candle；　but　will　expect　a　similar　effect　from　a　cause　which
is　similar　in　its　sensible　qualities　and　appearance。　If　you
assert；　therefore；　that　the　understanding　of　the　child　is
led　into　this　conclusion　by　any　process　of　argument　or
ratiocination；　I　may　justly　require　you　to　produce　that
argument；　nor　have　you　any　pretence　to　refuse　so　equitable　a
demand。　You　cannot　say　that　the　argument　is　abstruse；　and
may　possibly　escape　your　enquiry；　since　you　confess　that　it
is　obvious　to　the　capacity　of　a　mere　infant。　If　you
hesitate；　therefore；　a　moment；　or　if；　after　reflection；　you
produce　any　intricate　or　pr