BOOK I PART IV
and unnatural, and the ideas faint and obscure;
though the principles of judgment, and the bal-
lancing of opposite causes be the same as at the
very beginning; yet their influence on the imag-
ination, and the vigour they add to, or diminish
from the thought, is by no means equal. Where
the mind reaches not its objects with easiness
and facility, the same principles have not the
same effect as in a more natural conception of
the ideas; nor does the imagination feel a sen-
sation, which holds any proportion with that
which arises from its common judgments and
opinions. The attention is on the stretch: The
posture of the mind is uneasy; and the spirits
being diverted from their natural course, are
not governed in their movements by the same
laws, at least not to the same degree, as when
they flow in their usual channel.