ty, and have
it in our choice whether we wili advance a step farther. This
proceeds from the immediate presence of the evil, which influences the
imagination in the same manner as the certainty of it would do; but
being encountered by the reflection on our security, is immediately
retracted, and causes the same kind of passion, as when from a
contrariety of chances contrary passions are produced.

Evils, that are certain, have sometimes the same effect in producing
fear, as the possible or impossible. Thus a man in a strong prison
well-guarded, without the least means of escape, trembles at the thought
of the rack, to which he is sentenced. This happens only when the
certain evil is terrible and confounding; in which case the mind
continually rejects it with horror, while it continually presses in
upon the thought. The evil is there flxed and established, but the mind
cannot endure to fix upon it; from which fluctuation and uncertainty
there arises a passion of much the same appearance with fear.

But it is not only where good or evil is uncertain, as to its existence,
but also as to its kind, that fear or hope arises. Let one be told by
a person, whose veracity he cannot doubt of, that one of his sons is
suddenly killed, it is evident the passion this event would occasion,
would not settle into pure grief, till he got certain information, which
of his sons he had lost. Here there is an evil certain, but the kind of
it uncertain. Consequently the fear we feel on this occasion is without
the least mixture of joy, and arises merely from the fluctuation of the
fancy betwixt its objects. And though each side of the question produces
here the same passion, yet that passion cannot settle, but receives
from the imagination a tremulous and unsteady motion, resembling in its
cause, as well as in its sensation, the mixture and contention of grief
and joy.

From these principles we may account for a phaenomenon in the passions,
which at first sight seems very extraordinary, viz, that surprize is apt
to change into fear, and every thing that is unexpected affrights
us. The most obvious conclusion from this is, that human nature is in
general pusillanimous; since upon the sudden appearance of any object.
we immediately conclude it to be an evil, and without waiting till we
can examine its nature, whether it be good or bad, are at first affected
with fear. This I say is the most obvious conclusion; but upon farther
examination we