L
o
bing,
&C.
of any decinlll fraaion by logarilhnil, it mufl
be obfemd, Ihat the firn fignificanl figure of Ihe power
be pUl fo manyplaces below Ihe place of unils, as IRe in.
dex of ils logarilhm wanls of 10, 100,
Óle.
multiplied
by Ibe index of Ihe power.
T••rlran Ih4 mIlo/powm
6j'LoGH1THMS.
G
1
c.
To find mean prop,,¡iona/¡ ¡(/weln a.'!
I'IJH
nUlnh:rJ.
S\lbtr.a the logarithm of the lea(l term from the lo.
garilhm of Ihe greaten, and divide the remainder by
l
number more by one Ihan Ihe number of mean5 defired I
theo add Ihe quoticnt to Ihe loglrilhm of Ihe leafl term
(or fubtral1 it from Ihe logarilhm of Ihe greatea) conti.
n\laUy, and il will give the logarilbms of. all the meaD
D¡, ide Ihe
logarit~m
O!
I~e
numbe.r by the index of pro¡iorfionals req\lired.
1he power, tbe quollenl
IS
the Joganthm of Ihe root
Example. Lel Ihreo meaDproportionals be fought,
fougbt.
bClween 106 and 100.
LogarilAm of 106=
2.025~058
Log.aritbm of 100= 2.0COO"l'O
Logaritbm of Ih:
le~(l
lerm 100 added
Lo,gariihm of the 6r(l meaD
IC!lI'4673846
Logarilhm of the fecond mean 102'9563°14
Logaritlllll of. Ihe Ihird mean 1°44670483
Logarilhru of the grem(l lerm 106
2.0000000
2.0
06 316
4.75
2.0 t26p9·5
2.0
18
9794.
2
5
2.
02 53°59.
L
o
1"
OGIC,
the arl of thinking and reafoning junIYi or,
:i..J
it may be defiaed tlie (cieoee or hi(lory of Ihe hu·
/nao mind, inafmuch as it tracel the progrefs of our
knowledge froin our fir(l and
11)0(1
fimple Ihrough all their
Bifferenl combioation5, conception5. and all tho(e nume·
rous deduaions thal re(ult from varioufly comparing Ihem
one witb anolher.
The
pre~i(e
bufioefs of logie, Iherefore, i5
10
explain
die nature orthe' human.mind, and the proper manner
of conduaing it5 (everal
po\~m,
iD order to the attaio·
ment of trulh aod knowledge. lllays open .thofe errors
20d miflake5 we are 'apt, through inmenlion, to run in·
to; and teaches us how
10
dillinguifh between truth: and
G
1
c.
whal oDly carries the appmance of il. By lhis .mean.
we grow acquainted wilb the nature and forceof tbe un.
derflanding i fee whal thing5 lie wilhio in reach i whers
\Ve may attaincertainlY and demontlralioD; aDd when ws
mufl be cooteoted Wilh probability.
Thi5 (cience is generally divided iOlo four pam,
viz.
Pmep¡ion, J.Jgmml, R'4foning,
aod
Mtlh,d. ·
This
divifion comprehends the whole hi(lory of tbe feoralions
and opemions of the humaD mind. But wemu(l refer Ihe
reader for Ihe 6rtl pan,
viz. P{rcep¡i,n,
and
Id,."
ta
METAPH VS
tcs. where it will be more conveniently and fui,
Iy Irealed. and confine ourfelm in ,this place lO the Ihres
la(l,
viz. JudgmeRI, Rea/Ming, and MelhoJ.
PART
1.
01
J
U D G M E N
1:.
T
HE
miod being furnifhed with ideas, its nexl
(I~p
io.tbe way to knolVledge is, Ihe comparing thefe ideas
logelher, in order to judge of Ibeir agreement or dif.·
greemeol. In this joint view of our ideas, if tbe rela.
tion i5 (uch, ., to be iml]1edialely difcoverable by the
bare infpedion of the mind i the judgments tbence ob·
tained are called
inluilive;
for in. this cafe, a mere ato
tenlioo
10
Ibe ideas compared, fullices to lel us fee, how
far tbeyare conneded or disjoined.. Thus,
Ihal lhe wh.I,
iJ
grealrr Ihan any o/ il, p.rll,
is an iotuilive judg·
Ilieot, nOlhing more being required
10
convince us of its
• IrUlh. Ih. n an menlion
10
Ihe ideas of
whole
and
parl,
Aod Ibis
100
is Ihe mfon, why we call the aa of the
mind forming Ihefe judgmenls,
in¡l/ilion;
as it is indeed
DOmore, Ihan ao immtdiale perceplion of Ihe agreement
or difagreemcol of any two ide.,.
!JUI il is
10
be obferved, lhal our knowledge of this
kind refpeas ooly our ideas, and lhe relation5 betweea
them i aod tberefore can ferre only ., a foundation
10
fueh reafoniog5 as are employed in invetligating Ihefe
rdations. Now many of our judgments are converfaDI
aboul faéls, and Ihe real exitlence of things, which can.
DOt be traced by Ihe bare conlemplalion of Qur ideas.
!t
does not follow, becau(e
1
havethe idea of acirele iD my
mind, Ihal therefore a figure
anfwering.toIhat idea, has
a real exi(lence io n'turé.
1
can form
10
myfelf the nQ·
tion of a centaur, or goldeo mounlain, but ncver ima.
gine on Ihat account, tbat eilher of Ibem exifl. Whal
then are Ihe grounds of our judgmenr in reladon to (.Iis
?
Experimce
and
IrflimMy.
By
e./,eritnce
we are io·
formed of Ihe exiflence of Ihe (everal objeéls which fur·
round us. and operate upoo our fenfes.
T,jlimony
i5 of
a wider eXtenl, and reache5 not only to objeas beyond
thc prerent (phm of our obfmalion, but airo
10
(,lis
and