Now I have observed, that those two faculties of the mind, the
imagination and passions, assist each other in their operations when
their propensities are similar, and when they act upon the same object.
The mind has always a propensity to pass from a passion to any other
related to it; and this propensity is forwarded when the object of the
one passion is related to that of the other. The two impulses concur
with each other, and render the whole transition more smooth and easy.
But if it should happen, that while the relation of ideas, strictly
speaking, continues the same, its influence, in causing a transition
of the imagination, should no longer take place, it is evident its
influence on the passions must also cease, as being dependent entirely
on that transition. This is the reason why pride or humility is not
transfused into love or hatred with the same ease, that the latter
passions are changed into the former. If a person be my brother I am
his likewise: but though the relations be reciprocal they have very
different effects on the imagination. The passage is smooth and open
from the consideration of any person related to us to that of ourself,
of whom we are every moment conscious. But when the affections are once
directed to ourself, the fancy passes not with the same facility from
that object to any other person, how closely so ever connected with us.
This easy or difficult transition of the imagination operates upon the
passions, and facilitates or retards their transition, which is a clear
proof, that these two faculties of the passions and imagination are
connected together, and that the relations of ideas have an influence
upon the affections. Besides innumerable experiments that prove this,
we here find, that even when the relation remains; if by any particular
circumstance its usual effect upon the fancy in producing an association
or transition of ideas, is prevented; its usual effect upon the
passions, in conveying us from one to another, is in like manner
prevented.
Some may, perhaps, find a contradiction betwixt this phænomenon
and that of sympathy, where the mind passes easily from the idea of
ourselves to that of any other object related to us. But this difficulty
will vanish, if we consider that in sympathy our own person is not the
object of any passion, nor is there any thing, that fixes our attention
on ourselves; as in the present case, where we are supposed to be
actuated with pride or humility. Ourself, independent of the perception
of every other object, is in reality nothing: For which reason we must
turn our view to external objects; and it is natural for us to consider
with most attention such as lie contiguous to us, or resemble us. But
when self is the object of a passion, it is not natural to quit the
consideration of it, till the passion be exhausted: in which case the
double relations of impressions and ideas can no longer operate.