this； whether they have objects at all。 This reality is supplied by
pure practical reason； and theoretical reason has nothing further to
do in this but to think those objects by means of categories。 This； as
we have elsewhere clearly shown； can be done well enough without
needing any intuition （either sensible or supersensible） because the
categories have their seat and origin in the pure understanding；
simply as the faculty of thought； before and independently of any
intuition； and they always only signify an object in general； no
matter in what way it may be given to us。 Now when the categories
are to be applied to these ideas； it is not possible to give them
any object in intuition； but that such an object actually exists；
and consequently that the category as a mere form of thought is here
not empty but has significance； this is sufficiently assured them by
an object which practical reason presents beyond doubt in the
concept of the summum bonum； the reality of the conceptions which
are required for the possibility of the summum bonum； without；
however； effecting by this accession the least extension of our
knowledge on theoretical principles。
When these ideas of God； of an intelligible world （the kingdom of
God）； and of immortality are further determined by predicates taken
from our own nature； we must not regard this determination as a
sensualizing of those pure rational ideas （anthropomorphism）； nor as a
transcendent knowledge of supersensible objects； for these
predicates are no others than understanding and will； considered too
in the relation to each other in which they must be conceived in the
moral law； and therefore； only so far as a pure practical use is
made of them。 As to all the rest that belongs to these conceptions
psychologically； that is； so far as we observe these faculties of ours
empirically in their exercise （e。g。； that the understanding of man
is discursive； and its notions therefore not intuitions but
thoughts； that these follow one another in time； that his will has its
satisfaction always dependent on the existence of its object； etc。；
which cannot be the case in the Supreme Being）； from all this we
abstract in that case； and then there remains of the notions by
which we conceive a pure intelligence nothing more than just what is
required for the possibility of conceiving a moral law。 There is
then a knowledge of God indeed； but only for practical purposes；
and； if we attempt to extend it to a theoretical knowledge； we find an
understanding that has intuitions； not thoughts； a will that is
directed to objects on the existence of which its satisfaction does
not in the least depend （not to mention the transcendental predicates；
as； for example； a magnitude of existence； that is duration； which；
however； is not in time； the only possible means we have of conceiving
existence as magnitude）。 Now these are all attributes of which we
can form no conception that would help to the knowledge of the object；
and we learn from this that they can never be used for a theory of
supersensible beings； so that on this side they are quite incapable of
being the foundation of a speculative knowledge； and their use is
limited simply to the practice of the moral law。
This last is so obvious； and can be proved so clearly by fact；
that we may confidently challenge all pretended natural theologians （a
singular name）* to specify （over and above the merely ontological
predicates） one single attribute； whether of the understanding or of
the will； determining this object of theirs； of which we could not
show incontrovertibly that； if we abstract from it everything
anthropomorphic； nothing would remain to us but the mere word； without
our being able to connect with it the smallest notion by which we
could hope for an extension of theoretical knowledge。 But as to the
practical； there still remains to us of the attributes of
understanding and will the conception of a relation to which objective
reality is given by the practical law （which determines a priori
precisely this relation of the understanding to the will）。 When once
this is done； then reality is given to the conception of the object of
a will morally determined （the conception of the summum bonum）； and
with it to the conditions of its possibility； the ideas of God；
freedom； and immortality； but always only relatively to the practice
of the moral law （and not for any speculative purpose）。
*Learning is properly only the whole content of the historical
sciences。 Consequently it is only the teacher of revealed theology
that can be called a learned theologian。 If； however； we choose to
call a man learned who is in possession of the rational sciences
（mathematics and philosophy）； although even this would be contrary
to the signification of the word （which always counts as learning only
that which one must be 〃learned〃 and which； therefore； he cannot
discover of himself by reason）； even in that case the philosopher
would make too poor a figure with his knowledge of God as a positive
science to let himself be called on that account a learned man。
According to these remarks it is now easy to find the answer to
the weighty question whether the notion of God is one belonging to
physics （and therefore also to metaphysics； which contains the pure
a priori principles of the former in their universal import） or to
morals。 If we have recourse to God as the Author of all things； in
order to explain the arrangements of nature or its changes； this is at
least not a physical explanation； and is a plete confession that
our philosophy has e to an end； since we are obliged to assume
something of which in itself we have otherwise no conception； in order
to be able to frame a conception of the possibility of what we see
before our eyes。 Metaphysics； however； cannot enable us to attain by
certain inference from the knowledge of this world to the conception
of God and to the proof of His existence； for this reason； that in
order to say that this world could be produced only by a God
（according to the conception implied by this word） we should know this
world as the most perfect whole possible； and for this purpose
should also know all possible worlds （in order to be able to pare
them with this）； in other words； we should be omniscient。 It is
absolutely impossible； however； to know the existence of this Being
from mere concepts； because every existential proposition； that is；
every proposition that affirms the existence of a being of which I
frame a concept； is a synthetic proposition； that is； one by which I
go beyond that conception and affirm of it more than was thought in
the conception itself； namely； that this concept in the
understanding has an object corresponding to it outside the
understanding； and this it is obviously impossible to elicit by any
reasoning。 There remains； therefore； only one single process
possible for reason to attain this knowledge； namely； to start from
the supreme principle of its pure practical use （which in every case
is directed simply to the existence of something as a consequence of
reason） and thus determine its object。 Then its inevitable problem；
namely； the necessary direction of the will to the summum bonum；
discovers to us not only the necessity of assuming such a First
Being in reference to the possibility of this good in the world；
but； what is most remarkable； something which reason in its progress
on the path of physical nature altogether failed to find； namely； an
accurately defined conception of this First Being。 As we can know only
a small part of this world； and can still less pare it with all
possible worlds； we may indeed from its order； design； and
greatness； infer a wise； good； powerful； etc。； Author of it； but not
that He is all…wise； all…good； all…powerful； etc。 It may indeed very
well be granted that we should be justified in supplying this
inevitable defect by a legitimate and reasonable hypothesis； namely；
that when wisdom； goodness； etc； are displayed in all the parts that
offer themselves to our nearer knowledge； it is just the same in all
the rest； and that it would therefore be reasonable to ascribe all
possib