892 IMMANUELKANT
natural laws comes to an end, there too all explanation ceases, and nothing remains but
defense (i.e., refutation of the objections from those who pretend to have seen more
deeply into the essence of things and who boldly declare freedom to be impossible). We
can show them only that the supposed contradiction they have discovered lies nowhere
else than in their necessarily regarding man [only] as appearance in order to make natural
law valid with respect to human actions, and now when we require them to think of man
quaintelligence as a thing regarded as it is in itself, they still persist in considering him
as appearance [only]. Obviously, then, the detachment of his causality (his will) from all
natural laws of the world of sense in one and the same subject is a contradiction, but this
disappears when they reconsider and confess, as is reasonable, that behind the appear-
ances things regarded as they are in themselves must stand as their hidden ground, and
that we cannot expect the laws of the activity of these grounds to be the same as those
under which their appearances stand.
The subjective impossibility of explaining the freedom of the will is the same as
the impossibility of discovering and explaining an interest* which man can take in
moral laws. Nevertheless, he does actually take an interest in them, and the foundation
of this interest in us we will call the moral feeling. This moral feeling has been erro-
neously construed by some as the standard for our moral judgment, whereas it must be
regarded rather as the subjective effect which the law has upon the will to which reason
alone gives objective grounds.
In order to will an action which reason alone prescribes to the sensuously
affected rational being as the action which he ought to will, there is certainly required
a power of will to instill a feeling of pleasure of satisfaction in the fulfilment of duty,
and hence there must be a causality of reason to determine sensibility in accordance
with its own principles. But it is wholly impossible to discern, i.e., to make a priori
conceivable, how a mere thought containing nothing sensuous is able to produce a sen-
sation of pleasure or displeasure. For that is a particular kind of causality of which, as
of all causality, we cannot determine anything a prioribut must consult experience
only. But since experience can exemplify the relation of cause to effect only as sub-
sisting between two objects of experience, while here pure reason by mere Ideas
(which furnish no object for experience) is to be the cause of an effect which does lie
within experience, an explanation of how and why the universality of the maxim as law
(and hence morality) interests us is completely impossible for us men. Only this much
is certain: that it is valid for us not because it interests us (for that is heteronomy and
dependence of practical reason on sensibility, i.e., on a basic feeling; and thus it could
never be morally legislating); but that it interests us because it is valid for us as men,
inasmuch as it has arisen from our will as intelligence and hence from our proper self;
but what belongs to mere appearance is necessarily subordinated to the character of the
thing regarded as it is in itself.460
461
*Interest is that by which reason becomes practical (i.e., a cause determining the will). We therefore
say only of a rational being that he takes an interest in something; irrational creatures feel only sensuous
impulses. A direct interest in the action is taken by reason only if the universal validity of its maxim is a
sufficient determining ground of the will. Only such an interest is pure. But if reason can determine the will
only by means of another object of desire or under the presupposition of a particular feeling of the subject,
reason takes merely an indirect interest in the action, and since reason for itself alone without experience can
discover neither objects of the will nor a particular feeling which lies at its root, that indirect interest would be
only empirical and not a pure interest of reason. The logical interest of reason in advancing its insights is
never direct but rather presupposes purposes for which they are to be used.