The Critique of Pure Reason | Page 4

comprehensibility of a system of speculative cognition, connected
under a single principle, we may say with equal justice: many a book
would have been much clearer, if it had not been intended to be so very
clear. For explanations and examples, and other helps to intelligibility,
aid us in the comprehension of parts, but they distract the attention,
dissipate the mental power of the reader, and stand in the way of his
forming a clear conception of the whole; as he cannot attain soon
enough to a survey of the system, and the colouring and
embellishments bestowed upon it prevent his observing its articulation
or organization--which is the most important consideration with him,
when he comes to judge of its unity and stability.
The reader must naturally have a strong inducement to co-operate with
the present author, if he has formed the intention of erecting a complete
and solid edifice of metaphysical science, according to the plan now
laid before him. Metaphysics, as here represented, is the only science
which admits of completion--and with little labour, if it is united, in a
short time; so that nothing will be left to future generations except the
task of illustrating and applying it didactically. For this science is
nothing more than the inventory of all that is given us by pure reason,
systematically arranged. Nothing can escape our notice; for what
reason produces from itself cannot lie concealed, but must be brought
to the light by reason itself, so soon as we have discovered the common
principle of the ideas we seek. The perfect unity of this kind of
cognitions, which are based upon pure conceptions, and uninfluenced
by any empirical element, or any peculiar intuition leading to
determinate experience, renders this completeness not only practicable,
but also necessary.

Tecum habita, et noris quam sit tibi curta supellex. -- Persius. Satirae iv.
52.
Such a system of pure speculative reason I hope to be able to publish
under the title of Metaphysic of Nature*. The content of this work
(which will not be half so long) will be very much richer than that of
the present Critique, which has to discover the sources of this cognition
and expose the conditions of its possibility, and at the same time to
clear and level a fit foundation for the scientific edifice. In the present
work, I look for the patient hearing and the impartiality of a judge; in
the other, for the good-will and assistance of a co-labourer. For,
however complete the list of principles for this system may be in the
Critique, the correctness of the system requires that no deduced
conceptions should be absent. These cannot be presented a priori, but
must be gradually discovered; and, while the synthesis of conceptions
has been fully exhausted in the Critique, it is necessary that, in the
proposed work, the same should be the case with their analysis. But this
will be rather an amusement than a labour.
[*Footnote: In contradistinction to the Metaphysic of Ethics. This work
was never published.]

PREFACE TO THE SECOND EDITION, 1787
Whether the treatment of that portion of our knowledge which lies
within the province of pure reason advances with that undeviating
certainty which characterizes the progress of science, we shall be at no
loss to determine. If we find those who are engaged in metaphysical
pursuits, unable to come to an understanding as to the method which
they ought to follow; if we find them, after the most elaborate
preparations, invariably brought to a stand before the goal is reached,
and compelled to retrace their steps and strike into fresh paths, we may
then feel quite sure that they are far from having attained to the
certainty of scientific progress and may rather be said to be merely
groping about in the dark. In these circumstances we shall render an
important service to reason if we succeed in simply indicating the path

along which it must travel, in order to arrive at any results--even if it
should be found necessary to abandon many of those aims which,
without reflection, have been proposed for its attainment.
That logic has advanced in this sure course, even from the earliest times,
is apparent from the fact that, since Aristotle, it has been unable to
advance a step and, thus, to all appearance has reached its completion.
For, if some of the moderns have thought to enlarge its domain by
introducing psychological discussions on the mental faculties, such as
imagination and wit, metaphysical, discussions on the origin of
knowledge and the different kinds of certitude, according to the
difference of the objects (idealism, scepticism, and so on), or
anthropological discussions on prejudices, their causes and remedies:
this attempt, on the part of these authors, only shows their ignorance of
the peculiar nature of