practically right, then it is a law, because it is a categorical
imperative. Thus, practical laws refer to the will only, without
considering what is attained by its causality, and we may disregard
this latter (as belonging to the world of sense) in order to have them
quite pure.



II. THEOREM I.

{BOOK_1|CHAPTER_1 ^paragraph 15}



All practical principles which presuppose an object (matter) of
the faculty of desire as the ground of determination of the will are
empirical and can furnish no practical laws.

By the matter of the faculty of desire I mean an object the
realization of which is desired. Now, if the desire for this object
precedes the practical rule and is the condition of our making it a
principle, then I say (in the first place) this principle is in that
case wholly empirical, for then what determines the choice is the idea
of an object and that relation of this idea to the subject by which
its faculty of desire is determined to its realization. Such a
relation to the subject is called the pleasure in the realization of
an object. This, then, must be presupposed as a condition of the
possibility of determination of the will. But it is impossible to know
a priori of any idea of an object whether it will be connected with
pleasure or pain, or be indifferent. In such cases, therefore, the