could this acute writer allow an empirical origin of this concept；
since this is directly contradictory to the necessity of connection
which constitutes the essence of the notion of causality； hence the
notion was proscribed； and in its place was put custom in the
observation of the course of perceptions。
It resulted； however； from my inquiries； that the objects with which
we have to do in experience are by no means things in themselves；
but merely phenomena； and that although in the case of things in
themselves it is impossible to see how； if A is supposed； it should be
contradictory that B； which is quite different from A； should not also
be supposed （i。e。； to see the necessity of the connection between A as
cause and B as effect）； yet it can very well be conceived that； as
phenomena； they may be necessarily connected in one experience in a
certain way （e。g。； with regard to time…relations）； so that they
could not be separated without contradicting that connection； by means
of which this experience is possible in which they are objects and
in which alone they are cognisable by us。 And so it was found to be in
fact； so that I was able not only to prove the objective reality of
the concept of cause in regard to objects of experience； but also to
deduce it as an a priori concept by reason of the necessity of the
connection it implied； that is； to show the possibility of its
origin from pure understanding without any empirical sources； and
thus； after removing the source of empiricism； I was able also to
overthrow the inevitable consequence of this； namely； scepticism；
first with regard to physical science； and then with regard to
mathematics （in which empiricism has just the same grounds）； both
being sciences which have reference to objects of possible experience；
herewith overthrowing the thorough doubt of whatever theoretic
reason professes to discern。
But how is it with the application of this category of causality
（and all the others； for without them there can be no knowledge of
anything existing） to things which are not objects of possible
experience； but lie beyond its bounds？ For I was able to deduce the
objective reality of these concepts only with regard to objects of
possible experience。 But even this very fact； that I have saved
them； only in case I have proved that objects may by means of them
be thought； though not determined a priori； this it is that gives them
a place in the pure understanding； by which they are referred to
objects in general （sensible or not sensible）。 If anything is still
wanting； it is that which is the condition of the application of these
categories； and especially that of causality； to objects； namely；
intuition； for where this is not given； the application with a view to
theoretic knowledge of the object； as a noumenon； is impossible and；
therefore； if anyone ventures on it； is （as in the Critique of Pure
Reason） absolutely forbidden。 Still； the objective reality of the
concept （of causality） remains； and it can be used even of noumena；
but without our being able in the least to define the concept
theoretically so as to produce knowledge。 For that this concept；
even in reference to an object； contains nothing impossible； was shown
by this； that； even while applied to objects of sense； its seat was
certainly fixed in the pure understanding； and although； when referred
to things in themselves （which cannot be objects of experience）； it is
not capable of being determined so as to represent a definite object
for the purpose of theoretic knowledge； yet for any other purpose （for
instance； a practical） it might be capable of being determined so as
to have such application。 This could not be the case if； as Hume
maintained； this concept of causality contained something absolutely
impossible to be thought。
In order now to discover this condition of the application of the
said concept to noumena； we need only recall why we are not content
with its application to objects of experience； but desire also to
apply it to things in themselves。 It will appear； then； that it is not
a theoretic but a practical purpose that makes this a necessity。 In
speculation； even if we were successful in it； we should not really
gain anything in the knowledge of nature； or generally with regard
to such objects as are given； but we should make a wide step from
the sensibly conditioned （in which we have already enough to do to
maintain ourselves； and to follow carefully the chain of causes） to
the supersensible； in order to plete our knowledge of principles
and to fix its limits； whereas there always remains an infinite
chasm unfilled between those limits and what we know； and we should
have hearkened to a vain curiosity rather than a solid…desire of
knowledge。
But； besides the relation in which the understanding stands to
objects （in theoretical knowledge）； it has also a relation to the
faculty of desire； which is therefore called the will； and the pure
will； inasmuch as pure understanding （in this case called reason） is
practical through the mere conception of a law。 The objective
reality of a pure will； or； what is the same thing； of a pure
practical reason； is given in the moral law a priori； as it were； by a
fact； for so we may name a determination of the will which is
inevitable； although it does not rest on empirical principles。 Now； in
the notion of a will the notion of causality is already contained； and
hence the notion of a pure will contains that of a causality
acpanied with freedom； that is； one which is not determinable by
physical laws； and consequently is not capable of any empirical
intuition in proof of its reality； but； nevertheless； pletely
justifies its objective reality a priori in the pure practical law；
not； indeed （as is easily seen） for the purposes of the theoretical；
but of the practical use of reason。 Now the notion of a being that has
free will is the notion of a causa noumenon； and that this notion
involves no contradiction； we are already assured by the fact… that
inasmuch as the concept of cause has arisen wholly from pure
understanding； and has its objective reality assured by the deduction；
as it is moreover in its origin independent of any sensible
conditions； it is； therefore； not restricted to phenomena （unless we
wanted to make a definite theoretic use of it）； but can be applied
equally to things that are objects of the pure understanding。 But；
since this application cannot rest on any intuition （for intuition can
only be sensible）； therefore； causa noumenon； as regards the theoretic
use of reason； although a possible and thinkable； is yet an empty
notion。 Now； I do not desire by means of this to understand
theoretically the nature of a being； in so far as it has a pure
will； it is enough for me to have thereby designated it as such； and
hence to bine the notion of causality with that of freedom （and
what is inseparable from it； the moral law； as its determining
principle）。 Now； this right I certainly have by virtue of the pure；
not…empirical origin of the notion of cause； since I do not consider
myself entitled to make any use of it except in reference to the moral
law which determines its reality； that is； only a practical use。
If； with Hume； I had denied to the notion of causality all objective
reality in its ＇theoretic＇ use； not merely with regard to things in
themselves （the supersensible）； but also with regard to the objects of
the senses； it would have lost all significance； and being a
theoretically impossible notion would have been declared to be quite
useless； and since what is nothing cannot be made any use of； the
practical use of a concept theoretically null would have been
absurd。 But； as it is； the concept of a causality free from
empirical conditions； although empty； i。e。； without any appropriate
intuition）； is yet theoretically possible； and refers to an
indeterminate object； but in pensation significance is given to
it in the moral law and consequently in a practical sense。 I have；
indeed； no intuition which should determine its objective theoretic
reality； but not the less it has a real application； which is
exhibited in concreto in intention