UNDERSTANDING. 
keti from induction and analogy. This is 
tlie foundation of the rational assent. ThS 
practical depends upon the recurrency of 
tlie ideas, and the degree of agitation pro- 
duced by them in the mind. Hence reflec- 
tion makes' the practical assent grow for a 
long time after the rational is arisen to its 
height ; or, which is often the case, if the 
practical assent arises in any considerable 
degree, without the rational, it will gene- 
rate the rational. Thus the sanguine are 
apt to believe and assert what they hope to 
be true ; and the timorous what they fear. 
V. There are many speculative abstract 
propositions in logic, metaphysics, ethics, 
controversial divinity, &c. the evidence for 
w|iich is the coincidence or analogy of the 
abstract terms, in certain particular appli- 
cations of them, or as considered in their 
grammatical relations. This causes the ra- 
tional assent. As to the practical assent or 
dissent, it arises from the ideas of import- 
ance, reverence, piety, duty, ambition, jea- 
lousy, envy, self-interest, <Src. which inter- 
mix in these subjects, and thus, in some 
cases, add great strength to the rational 
assent, in others destroy it, and convert it 
into its opposite. 
On the whole it appears that rational 
assent has different causes in propositions, 
of different kinds, and practical assent in 
like manrrer : that the causes of rational 
are also different from those of practical : 
that there is, however, a great affinity and 
general resemblance in all the causes ; that 
rational and practical assent exert a perpe- 
tual reciprocal influence on each other ; 
and, consequently that the ideas belonging 
to assent and dissent, and their equivalents 
and relatives are highly complex, unless in 
the cases of very simple propositions, such 
as mathematical ones. For, besides the 
coincidence of ideas and terms, they in- 
clude, in other cases, ideas of utility, im- 
portance, respect, disrespect, ridicule, reli- 
gious affections, hope, fear, &c. and bear 
some gross general proportion to the vivid- 
ness of these ideas. 
It follows from the preceding statements, 
that vicious men, that is, alt persons who 
want practical faith, must be prejudiced 
against the historical and other foundations 
for rational faith in revealed religion. Fur- 
ther, it is impossible any person should be 
so sceptical as not to have the comple.x ideas 
denoted by the words assent and dissent 
associated with a great variety of proiiosi- 
tions in the same manner as m otlier pfcv- 
t'ciis ; jrst as he must have the same ideas 
in general affixed to the words of his nd- 
tive language, as other men have. An uni- 
versal sceptic is therefore no more than a 
person wdio varies from the common usage 
in his application of a certain set of words, 
viz. truth, certainty, assejit, dissent, &c. 
We shall close this article with the very 
important remarks on evidence, given by 
Hartley, in proposition 87 ; referring to the 
original those readers who wish to see how 
he illustrates or proves them by the em- 
ployment of simple mathematical expres- 
sions, and who are disposed to enter into 
his important observations respecting the 
ascertainment of truth and the advance- 
ment of kuow'ledge. 
1. If the evidences for any proposition, 
fact, &c. be dependant on each other, so 
that the first is required to support the 
second, the second the third, and so on ; 
that, is, if a failure of any one of the evi- 
dences renders all the rest of no value, the 
separate probability of each evidence must 
be very great in order to make the proposi- 
tion credible ; and this holds so much the 
more, as the dependent evidences are more 
numerous. 
2. If the evidences for any proposition, 
fact, &c. be independent on each other; 
that is, if they be not necessary to support 
each other, but concur, and can, each of 
them, when established upon its own pro- 
per evidences, be applied directly to esta- 
blish the proposition, fact, &c. in question ; 
the deficiency in the probability of each 
must be very great, in order to render the 
proposition perceptibly doubtful, and this 
holds so much the more, as the evidences 
are more numerous. 
3. The resulting probability may be suffi- 
ciently strong in dependent evidences, and 
of little value in independent ones, accord- 
ing as the separate probability of each evi- 
dence is greater or less. Thus the princi- 
pal facts of ancient history are not less pro- 
bable practically now, than ten or fifteen 
centuries ago ; nor less so then, than in the 
times immediately succeeding, because the 
diminution of evidence in each century is 
imperceptible. And for the same reason a 
large number of weak arguments prove 
little. 
4. It appears likewise, that the inequa- 
lity of the separate evidences does not pro- 
duce much alteration in these remarks. In 
like, manner, if the number of evidences, 
dependent or independent, be great, We 
may make great concessions as to the value 
of each. Again, a strong evidence in de- 
