1000000030

1019 / 1042

L o G
Tbis is Ihe mfoh, why, ;úlderto exctl remarbbly
in .ny ooe br.neh of Icarning, it is neeeíTary to have at
lea/l ¡ general acquain!anee \Vith the whole eirele of art!
and lcien"",. Th~ truth i9, _11 Ihe various divifiool of
human k(l()wledge are very nearly related among Ihem·
(e1'f!, and io iMume'able io/laom ferve to illufirate and
rel offeaeh olhe.. And a1tho' il is nOI 10 be denied, Ihal,
by 3n obnioale applieation lO ooe buneh of tludy, a mao
mar make eoofKlenble p.rogref9 aod aequire fome degree
of emioenee in il; yel his vie"! \ViII be always narrOIV
and ecolraéted, and he will waol Ihat ma/lerly difeern·
menl, IVhieh nOI ooly eoables us 10 purfue our difeove·
ries ",ilh eafe, bUI alfo, in hying Ihem opéo to other!, la
fpread a mlai. brighlnef! around IheOl. But when ou~
reafoning a particular feieaee, il is farther neeef·
fary, Ihu we mor~ oearly aequaiot ourfehes Wilh "hal'
eycr rel.ttl 10 Ihal ·feietlCe. A general knowledge is a
good prepmlioD, and enables us lO proeeed with eafe
and e~pedition', in whatever braneh of learning we apply
ID. ut lbenin Ihe mi.ute and iotricale qudtioDSof any
\Ve are by no meROS qualified 10 mfos wilh
ge, uDtil we hne perfeélly manered Ihe feieoee
10 whieh Ihey belons.
We come DOW lO the feeond thing requircd, in order
to a fumfsful progrer. in reafoning, oamely, Ihe !kili
t nd lalenl of applying iOlermedim ideas happily in all
putieular ionaoees Ihal eomeunder eoofideratioo. Ufe aod
nercife m Ihe be/l innruétors io Ihe prefent eafe. Aod
,herefore the Irue way 10 aequire this taleol is, by being
1Ilueheon.edaD! in tho(e (eiences where the arl ofreafooiog
i, allowed lO ,eigo in tbe greate/l perfeétioo. Henee it IVas
Ihlt Ihe ancienl!. who (o well underfiood the manner of
forming tbe mind, a1ways begao \Vilh
Ihe foundation of their philofophical /l the
~Dderltanding is by degrees habituated 10 truth, eon–
mas inCenfibly a eertaio foodoe(s (or it, and learns oever
to yield il! arreot 10 any propofitioo, bUI where the eri·
deoee is fuffieient 10 produce full eooviétion. For Ihis
r~ron Pla/~ has ealled mathemalieal Jemoonrati~ns the
ealharl;cll or purgatives o( Ihe Coul, as beiog Ihe pro·
'pcr m~os to citarle il from error, and .ellOl'e Ihat na·
tural exereue of il! faeuhies, ~ wbieh ju/l Ihiokiog con
Ms.
If thmrore we 1V0uld form our mind, to a babil of
rcafoniog c10fely and in train, we cannol take aoy more
e~min melhod, th.o the exereifing ourCelv., in. mathe·
mllical demonnmions, fo as 10 eonmét a kir.d of fami·
liarity Wilh them. Not Ihat IVe look upoo it al ne·
ceíTary Ihal all men lhould be deep malhematieians, but
that, ha.ing got the lIay of ,eafooing whieh Ihu nudy
nectrrari ly briogs lhe mind 10, theymay be able to traoC·
rer il to olher parts of koowledge, as th~y lhall have oc·
cafion. '
'RuI although Ihe fiudy of malhematieks be of all o·
Ihers lhe mon ufdul 10 form Ihe mind, aod gi.e it 10
mly relilh of trulh, yet ough! not olher patl! of philo·
fophy In be oegleéted. For Ihere alfo IVe mcet lVilh
many oppOrtUnilies of excrcifing the pOIVm 01' the uo·
dcrfianding : aod the variety offubjcéls oalllrally leads us
lO obCen·. alllhofe difl'crent lurns of Ihioking Ihat are
peculiarly adapled to¡he fevml idm 'ye e¡¡¡¡mine aod
c. 993
Ihe trulhs \Ve (eareh a(ler. For Ihis purpofe, befides Ihe
I\udy of malhemalickl, IVe ollghl to apply ourCél,e. di·
hgendy to the re2.ding of fueh ,ulhors as have diUin–
guilhed thcmfellcs for Ilrenglh of reaConing, aod a joll
aDd aeeurate maooer or Ihinkiog. F,'r- it is obrervable,
Ihat a miDd excreiled aod feafoned tot,uth, reldom refi,
fatisfied ioabarecontemplation of the argu~nls olfered
by Olhers, bm will be frequentlyeíT.yiog ils owo nrenglh,
and purfuing ilS diCeo.eries upon Ihe plao it i$mon " .
cu/lomed 10. Thus u-e iofeolibly a habit of tra–
cing trutbfrom or,e /lage to anolh fiovenigatiog
thole general rdatioos aod prop"liei, whieh we after–
IVards aferibe 10 particular ihings, accordi~g as we fi04
them eomp"heqded uncer I~e abnraél idm 10 whieh
Ihe properties beloog.
O[ ¡he for/JII o/ S)'¡¡oglfn/l.
HI THUTOwe naYe eonlentedourfelves wilh a geoe·
ral nOlioo of fyllogifms, and of Ihe pans of whieh lhey
~onfin. It .is now time I~ cnler al'lde more partieul?r1y
lotO the fubJe~, to ex.mloe Iheir various forms, and lay
opeo Ihe rules of argumentatiOA prop" 10 each. In the
fyllog!fms ment.ioned io, IVe ~ay oblerve, thal the miqdle
t~m, II the fubJel:l of the nlaJor propoJilioo, and Ihe pre.
dlcate of Ihe minoro Thi, difpofition, though Ihe moq
oatural aod obvi.oUI, is nOI howe'er neeeíTary; ji fre.
9uend y happenmog, that the middl, term is the fubjea
'?both .the preOlitres, o, the prediealeio bOlb; and fome.
time! dueétly cootrary, the predieate io Ihe nlajor, aod
Ihe fu~jeét in ~he m~n.,. Henee Ihe diflioélioo of (yllo.
glfms ,oto vanous klOds, ealledIgum by logieians. Fot
Igore, aeeordin~ ta their ufe of the 1V0rd, is nOlhioge/fe
bUI the order and difpofil ion of Ihe middl, Imh io any
frllogifm. Aod as Ihis difpofition is fourfold, fo Ihe fi.
gures of fyllogifms theoee ariliog are four in number.
W.~en the midd/e ¡e~m is Ihe fubjel:l of Ihe mojor propo.
fiuoo , and Ihe predlCale cf the ,ninor, IVe ha,e what is
caUed lhe ¡rJl figu re. If, on the olher hand, it is Ihe'
predicate of bOlh the premiíTes, Ihe fyllogifm i,-raid to be
in the ficond fig ure. Agaio, io Ihe Ihird IgUrt, Ihe
I.iddle ¡erm is the fubjeélof Ihe tl\'O premiíT~s. And
lafily, by making it the predieale of the mojor, and
Cubjeét of lhe minor, we obtaia fyllogifms io Ihe [ourth
Ic ure •
But befides this fourfold difiinétionof fyllogifms, Ihere
js alfo a fanher fubdivifioo of them in eyery figure, ario
fing from Ih~ qUJnlil).and qua/il), as they are ealled, of
the propofiliQns. Byquanlil) "e meaoth~ eonfideration
of propofitions as uni,erfal or panicular; by 9,/a/il)', ~s
aflirrpative or mgati.e. NolV al, inalllhe feveral di(po.
fitions of Ihe idd/e I"/JI, Ihepropofition of "hieh a fyl.
logifm may ~e either univHfal or particular.
.ffirma Qegalive; the due dmrmioOlion of thefe,
~nd fo puning Ihcm logether as Ihe lall s of ar ta·
tion require, eOonilule IVhat logiei"ns c¡,1I tl¡e oC
fyllogirDls. Of Ihefe 11Jcodi there,re adelermin mo
ber 10 mry figure, ioeludíng all the pullihle ways in
whieh propofilions dill'cring in 9/1anl//) or qua!tly can be
eombined, aceordiog 10 aoy dilpufitiuo"f Ihe middle Ima,
io order 10 mive at a jull eor.cJufion.
lhe di¡ifioo of ryllogifms mOlding 10 Olood ¡nd fi.
gure,