1808. | 
appreciable found: a higher ftill may be 
the (tate of a€tual /enfation: the higheft 
degree of all may be viclent pain or 
phrenzy ; but that an idea prefent fhould 
be alio datent, feems to involve no {mall 
degree of contradiétion. It admits of lit- 
tle doubt that in reverie, dreaming and 
delirium ideas are dilated and brightened 
(if | may fo exprefs myfelf) into a vivid 
diftingtne s uiual.y nit inferior and fome- 
times much fuperior to that of f{ nf>tions 
of impreffion. In thefe cafes they b-come 
truly fe {iti ns of con{cioutnefs not to be 
diftinguifhed from thofe of impreffion. 
When therefore the Exguirer fays that 
<‘the pe ceptions whicn in dreams we 
miliake tor fenfations are ideas,”” he feems 
to be incorreét in more refpe&is than one : 
in the firlt place, the images pretented in 
dreams, &c. are fir more lively and dif- 
ting *han thefe faint copies or relics of 
fenfaion of :mprefiion which we call ideas ; 
and feecndly, in the phrafeology of the 
Enquirer, perception 1s made a general 
term comprehending under it the lefs gene- 
ral terms, /enfation and idea. But what 
Jogician or what philologilt will agree to 
fach a claffification of terms? Sezfation 
is propeily the more general term, includ- 
ing wnder it the rerms zdea and perception. 
Ideas as they {pontaneoufly anfe in the 
mind as well as thofe mental feelings 
which we term volition, paffion, defire, &c. 
are comprehe ded under one divifion of 
fenfations, viz. fenfations of confciwufne/s, 
as is allo percepiton, which chicfly refers 
to fome judgment of the mind by which 
fenfations of impreflion are made the 
foundation, and ideas tie materials of 
knowledge. Following, with a little de- 
viation, the fteps of a deleivedly admired 
writer (D. SreEwarT, Outlines of Moral 
Philofopny, p. 21.) Y would fay, that fen. - 
fation implies a change in the {taté of the 
“mind produced by fome impreffion on the 
external organs of fen'e, or by fome af- 
fection of the internal organs ; while per- 
ception implies, in addition to that change, 
the judgment we form of the objects of 
fenfe or the fubjeéts of memory. Certain 
morbidaffections, as tinnitus aurium, fuffu- 
fio, vertigo, and others of the tribe of dif- 
eafes called by nofologitts Hallucinattones, 
are properly fenfat ons of confcioulnefs ; 
but the mind is not deceived; it forms 
no errone us\percepticn or miftaken pur- 
pofe in ccnfequence of thele fenfations. 
“When the perception ov judgment is vitia- 
ted, and correfponding volitions and aéti- 
ons follow, the difirder, according to its 
different concomitants and degre¢s, a- 
mounts to desrius ox infanity. 
Obfervations on Materialifm, the Ideal Sytem, &c. 
11 
6. The Exquirer feems alfo to be mif- 
taken in another affertion. He fays that 
“* Whereas fenfations can imprint ideas, 
ideas cannot imprict fenfations.” I wifh 
to declineufing the word “¢ zmprint,”’ which 
being a metaphorical term, may lead toa 
miftake; but I would fay that ideas can 
unqueftionably occafion fenfations. L 
have already obferved that the recollec— 
tion, 1. e. the zdea of a loathfome object 
will in a perfon of an irritable ftomach 
excie the very unpleafant fenfation of fick- 
nefs. The apprehenfion i. ¢., the idea of 
a difeafe affecting a particular part will, - 
in {ome conftitutions, produce a very lively 
fenfation of itching or pain in that part, 
wh'ch at the fame time fhall be perfectly 
free from: any other morbid affection s 
many other fimilar facts might be adduced. 
7. Lhe Enquirer jutly obferves that 
‘colour, fmell, and tafte are general 
terms.’”. Why he was not contented to 
reft in this obfervation, I cannot imagine. 
He goes on to remark, that ‘¢ there are 
biue, yellow, red, individual fenfations, 
whoie common phznomenon is called co~ 
lour ; but this impreflion, though it can 
be imaged in idea, is not -itfelf capable 
of being received apart by fenfe. It is 
obtained by abffraction.” Now J would 
afk, what is the meaning of a common 
phenomenon, or of the impreffion of a com- 
mon phenomenon imaged in idea ? If,as the 
Enquirer truly fays, ** Senfation is conver- 
fant only with individuals,” the famemuit 
be true of ideas. The generalization, the 
common acceptation belongs only to the 
term, colour. In fa, I fhonld think L 
talked as intelligibly when ufing the ex- 
preflions, a general landfcape, a general 
portrait, an abjiradé map or chart, as when 
ufing the terms ‘‘abfradét ov general ideas,” 
the exiflence of which I humbly conceive 
to be demonttratively impoffible.. To- 
wards the conclufion of his eflay the Bx- 
quirer {ays that ‘* whitenefs is an abftract 
idea :”” but he had before faid that ‘there 
are blue, yellow, red,’’ (and confequently- 
white) ‘* individual fenfations:”” the idea> 
of whitenefs then can hardly be calledan 
abftract idea, even in the language of 
the Ezxquirer, unlefs he be able to raife im 
his mind fuch an idea unaccompanied 
with that of any {ubftratum of that co- 
lour, as of chalk, fnow, milk, paper, or 
the like ; and if he be thus able, [ mutt 
admire in him a difcriminative power of 
imagination, which I do not myfelf pof- 
fefs, and can never hope to attain. 
8. Concurring as I do with much abler 
philofophers in the perfuafion that it is 
given to man to view only the pee 
2 6 
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