BOOK I PART III
ideas, which at first sight may be esteemed
different from any of these, but will be found
at the bottom to depend on the same origin.
When every individual of any species of ob-
jects is found by experience to be constantly
united with an individual of another species,
the appearance of any new individual of ei-
ther species naturally conveys the thought to
its usual attendant. Thus because such a par-
ticular idea is commonly annexed to such a
particular word, nothing is required but the
hearing of that word to produce the correspon-
dent idea; and it will scarce be possible for the
mind, by its utmost efforts, to prevent that tran-
sition. In this case it is not absolutely neces-
sary, that upon hearing such a particular sound
we should reflect on any past experience, and
consider what idea has been usually connected
with the sound. The imagination of itself sup-