e immediately
carries us to the idea of the other.

Being fully satisfyed on this head, I make a third set of experiments,
in order to know, whether any thing be requisite, beside the customary
transition, towards the production of this phaenomenon of belief. I
therefore change the first impression into an idea; and observe, that
though the customary transition to the correlative idea still remains,
yet there is in reality no belief nor perswasion. A present impression,
then, is absolutely requisite to this whole operation; and when after
this I compare an impression with an idea, and find that their only
difference consists in their different degrees of force and vivacity,
I conclude upon the whole, that belief is a more vivid and intense
conception of an idea, proceeding from its relation to a present
impression.

Thus all probable reasoning is nothing but a species of sensation. It is
not solely in poetry and music, we must follow our taste and sentiment,
but likewise in philosophy. When I am convinced of any principle, it
is only an idea, which strikes more strongly upon me. When I give the
preference to one set of arguments above another, I do nothing but
decide from my feeling concerning the superiority of their influence.
Objects have no discoverable connexion together; nor is it from any
other principle but custom operating upon the imagination, that we
can draw any inference from the appearance of one to the existence of
another.

It will here be worth our observation, that the past experience, on
which all our judgments concerning cause and effect depend, may operate
on our mind in such an insensible manner as never to be taken notice of,
and may even in some measure be unknown to us. A person, who stops
short in his journey upon meeting a river in his way, foresees the
consequences of his proceeding forward; and his knowledge of these
consequences is conveyed to him by past experience, which informs him of
such certain conjunctions of causes and effects. But can we think,
that on this occasion he reflects on any past experience, and calls
to remembrance instances, that he has seen or heard of, in order to
discover the effects of water on animal bodies? No surely; this is not
the method, in which he proceeds in his reasoning. The idea of sinking
is so closely connected with that of water, and the idea of suffocating
with that of sinking, that the mind makes the transition without the
assistance of the memo