In  these  cases  most  people  will  readily  agree  with
us ;  for,  by  a  very  natural  confusion  of  ideas,  when
ever  they  speak  of  perceptions  they  mostly  mean
visual  perceptions  :  because  with  sight  is  associated
the  clearest  knowledge  ;  because  also  the  hypothesis
of  our  perceptions  being  Copies  of  Things,  is
founded  upon  sight.  The  same  persons  who  would
willingly  admit  that  Pain  was  not  a  Copy  of  the
Fire,  nor  of  any  thing  in  the  nature  of  Fire,  ex
cept  in  its  effect  on  our  nerves,  would  protest  that
the  appearance  of  Fire  to  the  Eye  was  the  real  ap
pearance  of  the  Fire,  all  Eyes  apart,  and  quite
independent  of  human  vision.  If  all  Sentient
beings  were  at  once  swept  from  the  face  of  the
earth,  the  fire  would  have  no  attribute  at  all
resembling  Pain :  because  Pain  is  a  modification,
not  of  Fire,  but  of  a  sentient  being.  In  like
manner  if  all  Sentient  beings  were  at  once  swept
from  the  face  of  the  earth,  the  Fire  would  have  no
attributes  at  all  resembling  light  and  colour ;  be
cause  light  and  colour  (however  startling  the  asser
tion)  are  modifications  of  the  sentient  being,  caused
by  something  external,  but  no  more  resembling  its
cause  than  the  pain  inflicted  by  an  instrument  re
sembles  that  instrument.
