I have observed, with pleasure and thankfulness, in the pages of
various reviews and treatises, that the spirit of profound and
thorough investigation is not extinct in Germany, though it may have
been overborne and silenced for a time by the fashionable tone of a
licence in thinking, which gives itself the airs of genius, and that
the difficulties which beset the paths of criticism have not prevented
energetic and acute thinkers from making themselves masters of the
science of pure reason to which these paths conduct--a science which
is not popular, but scholastic in its character, and which alone can
hope for a lasting existence or possess an abiding value. To these
deserving men, who so happily combine profundity of view with a talent
for lucid exposition--a talent which I myself am not conscious of
possessing--I leave the task of removing any obscurity which may still
adhere to the statement of my doctrines. For, in this case, the danger
is not that of being refuted, but of being misunderstood. For my own
part, I must henceforward abstain from controversy, although I shall
carefully attend to all suggestions, whether from friends or
adversaries, which may be of use in the future elaboration of the
system of this propaedeutic. As, during these labours, I have advanced
pretty far in years this month I reach my sixty-fourth year--it will
be necessary for me to economize time, if I am to carry out my plan
of elaborating the metaphysics of nature as well as of morals, in
confirmation of the correctness of the principles established in
this Critique of Pure Reason, both speculative and practical; and I
must, therefore, leave the task of clearing up the obscurities of
the present work--inevitable, perhaps, at the outset--as well as,
the defence of the whole, to those deserving men, who have made my
system their own. A philosophical system cannot come forward armed
at all points like a mathematical treatise, and hence it may be
quite possible to take objection to particular passages, while the