BOOK I PART III
experience and observation. I suppose there
is an object presented, from which I draw a
certain conclusion, and form to myself ideas,
which I am said to believe or assent to. Here
it is evident, that however that object, which is
present to my senses, and that other, whose ex-
istence I infer by reasoning, may be thought to
influence each other by their particular powers
or qualities; yet as the phenomenon of belief,
which we at present examine, is merely inter-
nal, these powers and qualities, being entirely
unknown, can have no hand in producing it. It
is the present impression, which is to be consid-
ered as the true and real cause of the idea, and
of the belief which attends it. We must there-
fore endeavour to discover by experiments the
particular qualities, by which it is enabled to
produce so extraordinary an effect.