moral law is an imperative, which commands categorically, because
the law is unconditioned; the relation of such a will to this law is
dependence under the name of obligation, which implies a constraint to
an action, though only by reason and its objective law; and this
action is called duty, because an elective will, subject to
pathological affections (though not determined by them, and,
therefore, still free), implies a wish that arises from subjective
causes and, therefore, may often be opposed to the pure objective
determining principle; whence it requires the moral constraint of a
resistance of the practical reason, which may be called an internal,
but intellectual, compulsion. In the supreme intelligence the elective
will is rightly conceived as incapable of any maxim which could not at
the same time be objectively a law; and the notion of holiness,
which on that account belongs to it, places it, not indeed above all
practical laws, but above all practically restrictive laws, and
consequently above obligation and duty. This holiness of will is,
however, a practical idea, which must necessarily serve as a type to
which finite rational beings can only approximate indefinitely, and
which the pure moral law, which is itself on this account called holy,
constantly and rightly holds before their eyes. The utmost that finite
practical reason can effect is to be certain of this indefinite
progress of one's maxims and of their steady disposition to advance.
This is virtue, and virtue, at least as a naturally acquired
faculty, can never be perfect, because assurance in such a case
never becomes apodeictic certainty and, when it only amounts to
persuasion, is very dangerous.



VIII. THEOREM IV.