BOOK I PART III
the ideas of necessity, of power, and of efficacy,
are derived. These ideas, therefore, represent
not anything, that does or can belong to the
objects, which are constantly conjoined. This
is an argument, which, in every view we can
examine it, will be found perfectly unanswer-
able. Similar instances are still the first source
of our idea of power or necessity; at the same
time that they have no influence by their sim-
ilarity either on each other, or on any external
object. We must, therefore, turn ourselves to
some other quarter to seek the origin of that
idea.
Though the several resembling instances,
which give rise to the idea of power, have no
influence on each other, and can never produce
any new quality in the object, which can be the
model of that idea, yet the observation of this