principle of morality； just on account of the universality of the
legislation which makes it the formal supreme determining principle of
the will； without regard to any subjective differentes； is declared by
the reason to be a law for all rational beings； in so far as they have
a will； that is； a power to determine their causality by the
conception of rules； and； therefore； so far as they are capable of
acting according to principles； and consequently also according to
practical a priori principles （for these alone have the necessity that
reason requires in a principle）。 It is； therefore； not limited to
men only； but applies to all finite beings that possess reason and
will； nay； it even includes the Infinite Being as the supreme
intelligence。 In the former case； however； the law has the form of
an imperative； because in them； as rational beings； we can suppose a
pure will； but being creatures affected with wants and physical
motives； not a holy will； that is； one which would be incapable of any
maxim conflicting with the moral law。 In their case； therefore； the
moral law is an imperative； which mands 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； pulsion。 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 bees apodeictic certainty and； when it only amounts to
persuasion； is very dangerous。
VIII。 THEOREM IV。
The autonomy of the will is the sole principle of all moral laws and
of all duties which conform to them； on the other hand； heteronomy
of the elective will not only cannot be the basis of any obligation；
but is； on the contrary； opposed to the principle thereof and to the
morality of the will。
In fact the sole principle of morality consists in the
independence on all matter of the law （namely； a desired object）；
and in the determination of the elective will by the mere universal
legislative form of which its maxim must be capable。 Now this
independence is freedom in the negative sense； and this
self…legislation of the pure； and therefore practical； reason is
freedom in the positive sense。 Thus the moral law expresses nothing
else than the autonomy of the pure practical reason； that is； freedom；
and this is itself the formal condition of all maxims； and on this
condition only can they agree with the supreme practical law。 If
therefore the matter of the volition； which can be nothing else than
the object of a desire that is connected with the law； enters into the
practical law； as the condition of its possibility； there results
heteronomy of the elective will； namely； dependence on the physical
law that we should follow some impulse or inclination。 In that case
the will does not give itself the law； but only the precept how
rationally to follow pathological law； and the maxim which； in such
a case； never contains the universally legislative form； not only
produces no obligation； but is itself opposed to the principle of a
pure practical reason and； therefore； also to the moral disposition；
even though the resulting action may be conformable to the law。
REMARK。
Hence a practical precept； which contains a material （and
therefore empirical） condition； must never be reckoned a practical
law。 For the law of the pure will； which is free； brings the will into
a sphere quite different from the empirical； and as the necessity
involved in the law is not a physical necessity； it can only consist
in the formal conditions of the possibility of a law in general。 All
the matter of practical rules rests on subjective conditions； which
give them only a conditional universality （in case I desire this or
that； what I must do in order to obtain it）； and they all turn on
the principle of private happiness。 Now； it is indeed undeniable
that every volition must have an object； and therefore a matter； but
it does not follow that this is the determining principle and the
condition of the maxim； for； if it is so； then this cannot be
exhibited in a universally legislative form； since in that case the
expectation of the existence of the object would be the determining
cause of the choice； and the volition must presuppose the dependence
of the faculty of desire on the existence of something； but this
dependence can only be sought in empirical conditions and；
therefore； can never furnish a foundation for a necessary and
universal rule。 Thus； the happiness of others may be the object of the
will of a rational being。 But if it were the determining principle
of the maxim； we must assume that we find not only a rational
satisfaction in the welfare of others； but also a want such as the
sympathetic disposition in some men occasions。 But I cannot assume the
existence of this want in every rational being （not at all in God）。
The matter； then； of the maxim may remain； but it must not be the
condition of it； else the maxim could not be fit for a law。 Hence； the
mere form of law； which limits the matter； must also be a reason for
adding this matter to the will； not for presupposing it。 For
example； let the matter be my own happiness。 This （rule）； if I
attribute it to everyone （as； in fact； I may； in the case of every
finite being）； can bee an objective practical law only if I include
the happiness of others。 Therefore； the law that we should promote the
happiness of others does not arise from the assumption that this is an
object of everyone's choice； but merely from this； that the form of
universality which reason requires as the condition of giving to a
maxim of self…love the objective validity of a law is the principle
that determines the will。 Therefore it was not the object （the
happiness of others） that determined the pure will； but it was the
form of law only； by which I restricted my maxim； founded on
inclination； so as to give it the universality of a law； and thus to
adapt it to the practical reason； and it is this restriction alone；
and not the addition of an external spring； that can give rise to
the notion of the obligation to extend the maxim of my self…love to
the happiness of others。
REMARK II。
The direct opposite of the principle of morality is； when the
principle of private happiness is made the determining principle of
the will； and with this is to be reckoned； as I have shown above；
everything that places the determining principle which is to serve
as a law； anywhere but in the legislative form of the maxim。 This
contradiction； however； is not merely logical； like that which would
arise between rules empirically conditioned； if they were raised to
the rank of necessary principles of cognition； but is practical； and
would ruin morality altogether were not the voice of reason in
reference to the will so clear； so irrepressible； so distinctly
audible； even to the monest men。 It can only； indeed； be maintained
in the perplexing speculations of the schools； which are bold enough
to shut their ears against that heavenly voice； in order to support
a theory that costs no trouble。
Suppose that an acquaintance whom you otherwise liked were to
attempt to justify himself to you for having borne false witness；
first by alleging the； in his view； sacred duty of consulting his
own happiness； then by enumerating the advantages which he had
gained thereby； pointing out the prudence he had shown in securing
himself against detection； even by yourself； to whom he now reveals
the secret； only in order that he may be able to deny it at any
time； and suppose he were then to affirm； in all seriousness； that
he has fulfilled a true human duty； you would either laugh in his
face； or shrink back from him with disgust； and yet； if a man has
regulated his principles of action solely with a view to his own
advantage； you woul