SENSATION. 
The sensation thus connected with the 
complex idea is a perception. The accu- 
racy and vividness of the sensation depends 
entirely upon the sensitive power and its 
organs : the accuracy and vividness of the 
perception depends partly upon the accu- 
racy and vividness of the component sensa- 
tions, and partly upon the activity and energy 
of the retentive and associative powers. 
For a somewhat particular account of 
each sense, with statements respecting the 
share each has in forming our ideas, i. e, our 
notions and our feelings, we beg our readers 
to refer in this place to the following arti- 
cles, in the order in which we here detail 
them ; Sight, Touch, Taste, Smell, 
and Sound: and presuming upon the peru- 
sal of those articles, we shall here make a 
few general observations respecting sensa- 
tions. 
1. Sensations are the rudiments and ele- 
ments of all our ideas ; that is, of all out 
thoughts and feelings. — This is a position 
which perhaps few of those who are unac- 
quainted with the speculations of metaphy- 
sical writers would suppose to have been 
ever doubted. When an infant enters into 
the world, there is no appearance of any 
ideas being in its mind ; and no one can 
doubt, that if any human being could be 
deprived of all his organs and sensations, 
before any sensations had been received, 
that he would never have ideas. Yet it was 
once generally believed, that there are in 
every human being ideas born with him, 
which were called innate. What they were, 
or in what respects they differed from those 
which are indisputably received by means 
of the organs of sensation, was never, we 
apprehend, pointed out. Indeed the doc- 
trine of innate ideas rests merely on an ap- 
peal to ignorance ; and as soon as any pro- 
bable account of their origin is given,- all 
support of it falls at once. Before the grandi 
law of association was tolerably understood, 
the mode of the formation of many com- 
plex ideas could not be satisfactorily ascer- 
tained 5 and_ it must still be admitted, that 
we cannot in all cases fully trace the forma- 
tion of our complex ideas j but we can in 
a sufficient number to decide the point. 
Between those whose formation we can ex- 
plain, and those whose we cannot, there is 
no further difference than our greater or 
less acquaintance with the individual steps 
of the process. 
2. In the earliest exercise of the sensitive 
power, sensations are Simple, uncompounded 
with the relicts of former corresponding 
sensations ; but the sensations very soon be- 
come perceptions, that is, they instanta- 
neously recal the relicts of other corre- 
sponding sensations. This implies the ex- 
ercise of the retentive and associative pow- 
er; but as perceptions are almost hhi- 
formly produced by every exercise of the 
sensitive power, it may be proper to speak 
of them here in connection with sensations. 
That sensations in a somewhat advanced 
state of mental culture are usually percep- 
tions, any person may satisfy himself, by 
considering, that sensations are usually ac- 
companied either with an idea of an exter- 
nal object causing them, or (if they are 
thereby the effect of the state of the bodily 
system) with an idea of the sensation being 
in the part of the body in which the cause 
of the sensation exists ; both of which are 
complex ideas, formed from a great number 
of impressions, and which could in no in- 
stance be produced by any exertion of the 
sensitive power. — We, therefore, in many 
cases, without any impropriety, speak of 
perceptions and sensations indiscriminately; 
since a perception always implies a sensa- 
tion, and sensations most frequently are 
pel cep tions ; and accordingly we shall find 
in some writers that they are confounded, 
sometimes where they ought to be kept 
distinct. 
3. Considering man as an intellectual 
being, the accuracy and extent of his per- 
ceptions are of the first moment. They 
are, in fact, the materials of all knowledge 
respecting external objects, and in the early 
stages of mental culture are the only ob- 
jects of the understanding. Now the accu- 
racy and extent of the perception depends 
upon the vividness and efficaciousness of the 
component Sensations, and the number of 
them received from the same or similar ob- 
jects in different situations, and through the 
medium of different senses.— The object 
therefore of the early education of the hu- 
man being, should be to invigorate the or- 
gans of sense. Independently of the effects 
of the general healthiness of the system, it 
appears decidedly probable that the organs 
of sense are capable of being improved by 
exercise. It is the grand law of our frame, 
that moderate exertion increases the power 
of exertion ; and assuredly there are facts 
which lead to the same conclusion in this 
particular case. But this may be safely 
left to the natural eflfect df exertion. All 
that is to be done is to afford children the 
opportunity of exercising their senses on a 
variety of objects, and as ranch as possible 
