kind to judge whether such a system as that of the practical reason,
which is here developed from the critical examination of it, has
cost much or little trouble, especially in seeking not to miss the
true point of view from which the whole can be rightly sketched. It
presupposes, indeed, the Fundamental Principles of the Metaphysic of
Morals, but only in so far as this gives a preliminary acquaintance
with the principle of duty, and assigns and justifies a definite
formula thereof; in other respects it is independent. * It results
from the nature of this practical faculty itself that the complete
classification of all practical sciences cannot be added, as in the
critique of the speculative reason. For it is not possible to define
duties specially, as human duties, with a view to their
classification, until the subject of this definition (viz., man) is
known according to his actual nature, at least so far as is
necessary with respect to duty; this, however, does not belong to a
critical examination of the practical reason, the business of which is
only to assign in a complete manner the principles of its possibility,
extent, and limits, without special reference to human nature. The
classification then belongs to the system of science, not to the
system of criticism.

{PREFACE ^paragraph 15}



* A reviewer who wanted to find some fault with this work has hit
the truth better, perhaps, than he thought, when he says that no new
principle of morality is set forth in it, but only a new formula.
But who would think of introducing a new principle of all morality and
making himself as it were the first discoverer of it, just as if all