h arise from a double relation of impressions and ideas.

These indirect passions, being always agreeable or uneasy, give in their
turn additional force to the direct passions, and encrease our desire
and aversion to the object. Thus a suit of fine cloaths produces
pleasure from their beauty; and this pleasure produces the direct
passions, or the impressions of volition and desire. Again, when these
cloaths are considered as belonging to ourself, the double relation
conveys to us the sentiment of pride, which is an indirect passion; and
the pleasure, which attends that passion, returns back to the direct
affections, and gives new force to our desire or volition, joy or hope.

When good is certain or probable, it produces joy. When evil is in the
same situation there arises GRIEF or SORROW.

When either good or evil is uncertain, it gives rise to FEAR or HOPE,
according to the degrees of uncertainty on the one side or the other.

DESIRE arises from good considered simply, and AVERSION is derived from
evil. The WILL exerts itself, when either the good or the absence of the
evil may be attained by any action of the mind or body.

Beside good and evil, or in other words, pain and pleasure, the direct
passions frequently arise from a natural impulse or instinct, which is
perfectly unaccountable. Of this kind is the desire of punishment to our
enemies, and of happiness to our friends; hunger, lust, and a few other
bodily appetites. These passions, properly speaking, produce good and
evil, and proceed not from them, like the other affections.

None of the direct affections seem to merit our particular attention,
except hope and fear, which we shall here endeavour to account for.
It is evident that the very same event, which by its certainty would
produce grief or joy, gives always rise to fear or hope, when only
probable and uncertain. In order, therefore, to understand the reason
why this circumstance makes such a considerable difference, we must
reflect on what I have already advanced in the preceding book concerning
the nature of probability.

Probability arises from an opposition of contrary chances or causes, by
which the mind is not allowed to fix on either side, but is incessantly
tost from one to another, and at one moment is determined to consider
an object as existent, and at another moment as the contrary. The
imagination or understanding, call it which you please, fluctuates
betwixt the opposite views; and th