The Critique of Practical Reason | Page 4

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 the world before
him were ignorant what duty was or had been in thorough-going error?
But whoever knows of what importance to a mathematician a formula
is, which defines accurately what is to be done to work a problem, will
not think that a formula is insignificant and useless which does the
same for all duty in general.

In the second part of the Analytic I have given, as I trust, a sufficient
answer to the objection of a truth-loving and acute critic * of the
Fundamental Principles of the Metaphysic of Morals- a critic always
worthy of respect- the objection, namely, that the notion of good was
not established before the moral principle, as he thinks it ought to have
been. *(2) I have also had regard to many of the objections which have
reached me from men who show that they have at heart the discovery
of the truth, and I shall continue to do so (for those who have only their
old system before their eyes, and who have already settled what is to be
approved or disapproved, do not desire any explanation which might
stand in the way of their own private opinion.)

{PREFACE ^paragraph 20}
* [See Kant's "Das mag in der Theoric ricktig seyn," etc. Werke, vol.
vii, p. 182.]
*(2) It might also have been objected to me that I have not first defined
the notion of the faculty of desire, or of the feeling of Pleasure,
although this reproach would be unfair, because this definition might
reasonably be presupposed as given in psychology. However, the
definition there given might be such as to found the determination of
the faculty of desire on the feeling of pleasure (as is commonly done),
and thus the supreme principle of practical philosophy would be
necessarily made empirical, which, however, remains to be proved and
in this critique is altogether refuted. It will, therefore, give this
definition here in such a manner as it ought to be given, in order to
leave this contested point open at the beginning, as it should be. LIFE
is the faculty a being has of acting according to laws of the faculty of
desire. The faculty of DESIRE is the being's faculty of becoming by
means of its ideas the cause of the actual existence of the objects of
these ideas. PLEASURE is the idea of the agreement of the object, or
the action with the subjective conditions of life, i.e., with the faculty of
causality of an idea in respect of the actuality of its object (or with the
determination of the forces of the subject to action which produces it). I
have no further need for the purposes of this critique of notions
borrowed from psychology; the critique itself supplies the rest. It is
easily seen that the question whether the faculty of desire is always
based on pleasure, or whether under certain conditions pleasure only
follows the determination of desire, is by this definition left undecided,
for it is composed only of terms belonging to the pure understanding,
i.e., of categories which contain nothing empirical. Such precaution is
very desirable in all philosophy and yet is often neglected; namely, not
to prejudge questions by adventuring definitions before the notion has
been completely analysed, which is often very late. It may be observed
through the whole course of the critical philosophy (of the theoretical
as well as the practical reason) that frequent opportunity offers of
supplying defects in the old dogmatic method of philosophy, and of
correcting errors which are not observed until we make such rational

use of these notions viewing them as a whole.

When we have to study a particular faculty of the human mind in its
sources, its content, and its limits; then from the nature of human
knowledge we must begin with its parts, with an accurate and complete
exposition of them; complete, namely, so far as is possible in the
present state of our knowledge of its elements. But there is another
thing to be attended to which is of a more philosophical and
architectonic character, namely, to grasp correctly the idea of the whole,
and