BOOK I PART III
All the perceptions of the mind are of two
kinds, viz. impressions and ideas, which differ
from each other only in their different degrees
of force and vivacity. Our ideas are copyed
from our impressions, and represent them in
all their parts. When you would any way vary
the idea of a particular object, you can only en-
crease or diminish its force and vivacity. If you
make any other change on it, it represents a
different object or impression. The case is the
same as in colours. A particular shade of any
colour may acquire a new degree of liveliness
or brightness without any other variation. But
when you produce any other variation, it is no
longer the same shade or colour. So that as be-
lief does nothing but vary the manner, in which
we conceive any object, it can only bestow on
our ideas an additional force and vivacity. An
opinion, therefore, or belief may be most accu-