grounds； that the means thereto are possible or that its object is
real。 This； then； is an absolutely necessary requirement； and what
it pre…supposes is not merely justified as an allowable hypothesis；
but as a postulate in a practical point of view； and admitting that
the pure moral law inexorably binds every man as a mand （not as a
rule of prudence）； the righteous man may say： 〃I will that there be
a God； that my existence in this world be also an existence outside
the chain of physical causes and in a pure world of the understanding；
and lastly； that my duration be endless； I firmly abide by this； and
will not let this faith be taken from me； for in this instance alone
my interest； because I must not relax anything of it； inevitably
determines my judgement； without regarding sophistries； however unable
I may be to answer them or to oppose them with others more
plausible。*＇2＇
*But even here we should not be able to allege a requirement of
reason； if we had not before our eyes a problematical； but yet
inevitable； conception of reason； namely； that of an absolutely
necessary being。 This conception now seeks to be defined； and this； in
addition to the tendency to extend itself； is the objective ground
of a requirement of speculative reason； namely； to have a more precise
definition of the conception of a necessary being which is to serve as
the first cause of other beings； so as to make these latter knowable
by some means。 Without such antecedent necessary problems there are no
requirements… at least not of pure reason… the rest are requirements
of inclination。
*＇2＇ In the Deutsches Museum； February； 1787； there is a
dissertation by a very subtle and clear…headed man； the late
Wizenmann； whose early death is to be lamented； in which he disputes
the right to argue from a want to the objective reality of its object；
and illustrates the point by the example of a man in love； who
having fooled himself into an idea of beauty； which is merely a
chimera of his own brain； would fain conclude that such an object
really exists somewhere。 I quite agree with him in this； in all
cases where the want is founded on inclination； which cannot
necessarily postulate the existence of its object even for the man
that is affected by it； much less can it contain a demand valid for
everyone； and therefore it is merely a subjective ground of the
wish。 But in the present case we have a want of reason springing
from an objective determining principle of the will； namely； the moral
law； which necessarily binds every rational being； and therefore
justifies him in assuming a priori in nature the conditions proper for
it； and makes the latter inseparable from the plete practical use
of reason。 It is a duty to realize the summum bonum to the utmost of
our power； therefore it must be possible； consequently it is
unavoidable for every rational being in the world to assume what is
necessary for its objective possibility。 The assumption is as
necessary as the moral law； in connection with which alone it is
valid。
In order to prevent misconception in the use of a notion as yet so
unusual as that of a faith of pure practical reason； let me be
permitted to add one more remark。 It might almost seem as if this
rational faith were here announced as itself a mand； namely； that
we should assume the summum bonum as possible。 But a faith that is
manded is nonsense。 Let the preceding analysis； however； be
remembered of what is required to be supposed in the conception of the
summum bonum； and it will be seen that it cannot be manded to
assume this possibility； and no practical disposition of mind is
required to admit it； but that speculative reason must concede it
without being asked； for no one can affirm that it is impossible in
itself that rational beings in the world should at the same time be
worthy of happiness in conformity with the moral law and also
possess this happiness proportionately。 Now in respect of the first
element of the summum bonum； namely； that which concerns morality； the
moral law gives merely a mand； and to doubt the possibility of that
element would be the same as to call in question the moral law itself。
But as regards the second element of that object； namely； happiness
perfectly proportioned to that worthiness； it is true that there is no
need of a mand to admit its possibility in general； for theoretical
reason has nothing to say against it； but the manner in which we
have to conceive this harmony of the laws of nature with those of
freedom has in it something in respect of which we have a choice；
because theoretical reason decides nothing with apodeictic certainty
about it； and in respect of this there may be a moral interest which
turns the scale。
I had said above that in a mere course of nature in the world an
accurate correspondence between happiness and moral worth is not to be
expected and must be regarded as impossible； and that therefore the
possibility of the summum bonum cannot be admitted from this side
except on the supposition of a moral Author of the world。 I
purposely reserved the restriction of this judgement to the subjective
conditions of our reason； in order not to make use of it until the
manner of this belief should be defined more precisely。 The fact is
that the impossibility referred to is merely subjective； that is；
our reason finds it impossible for it to render conceivable in the way
of a mere course of nature a connection so exactly proportioned and so
thoroughly adapted to an end； between two sets of events happening
according to such distinct laws； although； as with everything else
in nature that is adapted to an end； it cannot prove； that is； show by
sufficient objective reason； that it is not possible by universal laws
of nature。
Now； however； a deciding principle of a different kind es into
play to turn the scale in this uncertainty of speculative reason。
The mand to promote the summum bonum is established on an objective
basis （in practical reason）； the possibility of the same in general is
likewise established on an objective basis （in theoretical reason；
which has nothing to say against it）。 But reason cannot decide
objectively in what way we are to conceive this possibility； whether
by universal laws of nature without a wise Author presiding over
nature； or only on supposition of such an Author。 Now here there es
in a subjective condition of reason； the only way theoretically
possible for it； of conceiving the exact harmony of the kingdom of
nature with the kingdom of morals； which is the condition of the
possibility of the summum bonum； and at the same time the only one
conducive to morality （which depends on an objective law of reason）。
Now since the promotion of this summum bonum； and therefore the
supposition of its possibility； are objectively necessary （though only
as a result of practical reason）； while at the same time the manner in
which we would conceive it rests with our own choice； and in this
choice a free interest of pure practical reason decides for the
assumption of a wise Author of the world； it is clear that the
principle that herein determines our judgement； though as a want it is
subjective； yet at the same time being the means of promoting what
is objectively （practically） necessary； is the foundation of a maxim
of belief in a moral point of view； that is； a faith of pure practical
reason。 This； then； is not manded； but being a voluntary
determination of our judgement； conducive to the moral （manded）
purpose； and moreover harmonizing with the theoretical requirement
of reason； to assume that existence and to make it the foundation of
our further employment of reason； it has itself sprung from the
moral disposition of mind； it may therefore at times waver even in the
well…disposed； but can never be reduced to unbelief。
IX。 Of the Wise Adaptation of Man's Cognitive Faculties
to his Practical Destination。
If human nature is destined to endeavour after the summum bonum；
we must suppose also that the measure of its cognitive faculties；
and particularly their relation to one another； is suitable to this
end。 Now the Critique of Pure Specula