BOOK II PART III
formation; in which case there is no room for
study or application. Let us search for the rea-
son of this phaenomenon.
It has been proved at large, that the influence
of belief is at once to inliven and infix any idea
in the imagination, and prevent all kind of hes-
itation and uncertainty about it. Both these cir-
cumstances are advantageous. By the vivacity
of the idea we interest the fancy, and produce,
though in a lesser degree, the same pleasure,
which arises from a moderate passion. As the
vivacity of the idea gives pleasure, so its cer-
tainty prevents uneasiness, by fixing one par-
ticular idea in the mind, and keeping it from
wavering in the choice of its objects. It is a
quality of human nature, which is conspicuous
on many occasions, and is common both to the
mind and body, that too sudden and violent a