Empirical principles of determination are not fit for any universal
external legislation； but just as little for internal； for each man
makes his own subject the foundation of his inclination； and in the
same subject sometimes one inclination； sometimes another； has the
preponderance。 To discover a law which would govern them all under
this condition； namely； bringing them all into harmony； is quite
impossible。
V。 PROBLEM I。
Supposing that the mere legislative form of maxims is alone the
sufficient determining principle of a will； to find the nature of
the will which can be determined by it alone。
Since the bare form of the law can only be conceived by reason； and
is； therefore； not an object of the senses； and consequently does
not belong to the class of phenomena； it follows that the idea of
it； which determines the will； is distinct from all the principles
that determine events in nature according to the law of causality；
because in their case the determining principles must themselves be
phenomena。 Now； if no other determining principle can serve as a law
for the will except that universal legislative form； such a will
must be conceived as quite independent of the natural law of phenomena
in their mutual relation； namely； the law of causality； such
independence is called freedom in the strictest； that is； in the
transcendental； sense； consequently； a will which can have its law
in nothing but the mere legislative form of the maxim is a free will。
VI。 PROBLEM II。
Supposing that a will is free； to find the law which alone is
petent to determine it necessarily。
Since the matter of the practical law； i。e。； an object of the maxim；
can never be given otherwise than empirically； and the free will is
independent on empirical conditions （that is； conditions belonging
to the world of sense） and yet is determinable； consequently a free
will must find its principle of determination in the law； and yet
independently of the matter of the law。 But； besides the matter of the
law； nothing is contained in it except the legislative form。 It is the
legislative form； then； contained in the maxim； which can alone
constitute a principle of determination of the ＇free＇ will。
REMARK。
Thus freedom and an unconditional practical law reciprocally imply
each other。 Now I do not ask here whether they are in fact distinct；
or whether an unconditioned law is not rather merely the consciousness
of a pure practical reason and the latter identical with the
positive concept of freedom； I only ask； whence begins our knowledge
of the unconditionally practical； whether it is from freedom or from
the practical law？ Now it cannot begin from freedom； for of this we
cannot be immediately conscious； since the first concept of it is
negative； nor can we infer it from experience； for experience gives us
the knowledge only of the law of phenomena； and hence of the mechanism
of nature； the direct opposite of freedom。 It is therefore the moral
law； of which we bee directly conscious （as soon as we trace for
ourselves maxims of the will）； that first presents itself to us； and
leads directly to the concept of freedom； inasmuch as reason
presents it as a principle of determination not to be outweighed by
any sensible conditions； nay； wholly independent of them。 But how is
the consciousness； of that moral law possible？ We can bee conscious
of pure practical laws just as we are conscious of pure theoretical
principles； by attending to the necessity with which reason prescribes
them and to the elimination of all empirical conditions； which it
directs。 The concept of a pure will arises out of the former； as
that of a pure understanding arises out of the latter。 That this is
the true subordination of our concepts； and that it is morality that
first discovers to us the notion of freedom； hence that it is
practical reason which； with this concept； first proposes to
speculative reason the most insoluble problem； thereby placing it in
the greatest perplexity； is evident from the following
consideration： Since nothing in phenomena can be explained by the
concept of freedom； but the mechanism of nature must constitute the
only clue； moreover； when pure reason tries to ascend in the series of
causes to the unconditioned； it falls into an antinomy which is
entangled in inprehensibilities on the one side as much as the
other； whilst the latter （namely； mechanism） is at least useful in the
explanation of phenomena； therefore no one would ever have been so
rash as to introduce freedom into science； had not the moral law；
and with it practical reason； e in and forced this notion upon
us。 Experience； however； confirms this order of notions。 Suppose
some one asserts of his lustful appetite that； when the desired object
and the opportunity are present； it is quite irresistible。 ＇Ask
him＇… if a gallows were erected before the house where he finds this
opportunity； in order that he should be hanged thereon immediately
after the gratification of his lust； whether he could not then control
his passion； we need not be long in doubt what he would reply。 Ask
him； however… if his sovereign ordered him； on pain of the same
immediate execution； to bear false witness against an honourable
man； whom the prince might wish to destroy under a plausible
pretext； would he consider it possible in that case to overe his
love of life； however great it may be。 He would perhaps not venture to
affirm whether he would do so or not； but he must unhesitatingly admit
that it is possible to do so。 He judges； therefore； that he can do a
certain thing because he is conscious that he ought； and he recognizes
that he is free… a fact which but for the moral law he would never
have known。
VII。 FUNDAMENTAL LAW OF THE PURE PRACTICAL REASON。
Act so that the maxim of thy will can always at the same time hold
good as a principle of universal legislation。
REMARK。
Pure geometry has postulates which are practical propositions； but
contain nothing further than the assumption that we can do something
if it is required that we should do it； and these are the only
geometrical propositions that concern actual existence。 They are；
then； practical rules under a problematical condition of the will； but
here the rule says： We absolutely must proceed in a certain manner。
The practical rule is； therefore； unconditional； and hence it is
conceived a priori as a categorically practical proposition by which
the will is objectively determined absolutely and immediately （by
the practical rule itself； which thus is in this case a law）； for pure
reason practical of itself is here directly legislative。 The will is
thought as independent on empirical conditions； and； therefore； as
pure will determined by the mere form of the law； and this principle
of determination is regarded as the supreme condition of all maxims。
The thing is strange enough； and has no parallel in all the rest of
our practical knowledge。 For the a priori thought of a possible
universal legislation which is therefore merely problematical； is
unconditionally manded as a law without borrowing anything from
experience or from any external will。 This； however； is not a
precept to do something by which some desired effect can be attained
（for then the will would depend on physical conditions）； but a rule
that determines the will a priori only so far as regards the forms
of its maxims； and thus it is at least not impossible to conceive that
a law； which only applies to the subjective form of principles； yet
serves as a principle of determination by means of the objective
form of law in general。 We may call the consciousness of this
fundamental law a fact of reason； because we cannot reason it out from
antecedent data of reason； e。g。； the consciousness of freedom （for
this is not antecedently given）； but it forces itself on us as a
synthetic a priori proposition； which is not based on any intuition；
either pure or empirical。 It would； indeed； be analytical if the
freedom of the will were presupposed； but to presuppose freedom as a
positive concept would require an intellectual intuition； which cannot
here be assumed； however； when we regard this law as given； it must be
observed； in order not to fall into any misconception； that it is
not an empirical fact； but the sole fact of the pure reason； which
thereby announces itself as originally legislative （sic volo； sic
jubeo）。
COROLLARY。
Pure reason is practical of itself alone and gives （to man） a
universal law which we call the moral law。
REMARK。
The fact just mentioned is undeniable。 It is only necessary to
analyse the judgement that men pass on the lawfulness of their
actions； in order to find that； whatever inclination may say to the
contrary； reason； incorruptible and selfconstrained； always
confronts the maxim of the will in any action with the pure will； that
is； with itself； considering itself as a priori practical。 Now this
principle of morality； just on account of the universality of the
legislation which make