this definition left undecided； for it is posed 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 pletely
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
plete exposition of them； plete； 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 from thence to get a view of all those parts as mutually
related by the aid of pure reason； and by means of their derivation
from the concept of the whole。 This is only possible through the
most intimate acquaintance with the system； and those who find the
first inquiry too troublesome； and do not think it worth their while
to attain such an acquaintance； cannot reach the second stage； namely；
the general view； which is a synthetical return to that which had
previously been given analytically。 It is no wonder then if they
find inconsistencies everywhere； although the gaps which these
indicate are not in the system itself； but in their own incoherent
train of thought。
I have no fear； as regards this treatise； of the reproach that I
wish to introduce a new language； since the sort of knowledge here
in question has itself somewhat of an everyday character。 Nor even
in the case of the former critique could this reproach occur to anyone
who had thought it through and not merely turned over the leaves。 To
invent new words where the language has no lack of expressions for
given notions is a childish effort to distinguish oneself from the
crowd； if not by new and true thoughts； yet by new patches on the
old garment。 If； therefore； the readers of that work know any more
familiar expressions which are as suitable to the thought as those
seem to me to be； or if they think they can show the futility of these
thoughts themselves and hence that of the expression； they would； in
the first case； very much oblige me； for I only desire to be
understood： and； in the second case； they would deserve well of
philosophy。 But； as long as these thoughts stand； I very much doubt
that suitable and yet more mon expressions for them can be found。*
*I am more afraid in the present treatise of occasional
misconception in respect of some expressions which I have chosen
with the greatest care in order that the notion to which they point
may not be missed。 Thus； in the table of categories of the Practical
reason under the title of Modality； the Permitted； and forbidden （in a
practical objective point of view； possible and impossible） have
almost the same meaning in mon language as the next category；
duty and contrary to duty。 Here； however； the former means what
coincides with； or contradicts； a merely possible practical precept
（for example； the solution of all problems of geometry and mechanics）；
the latter； what is similarly related to a law actually present in the
reason； and this distinction is not quite foreign even to mon
language； although somewhat unusual。 For example； it is forbidden to
an orator； as such； to forge new words or constructions； in a
certain degree this is permitted to a poet； in neither case is there
any question of duty。 For if anyone chooses to forfeit his
reputation as an orator； no one can prevent him。 We have here only
to do with the distinction of imperatives into problematical；
assertorial； and apodeictic。 Similarly in the note in which I have
pared the moral ideas of practical perfection in different
philosophical schools； I have distinguished the idea of wisdom from
that of holiness； although I have stated that essentially and
objectively they are the same。 But in that place I understand by the
former only that wisdom to which man （the Stoic） lays claim； therefore
I take it subjectively as an attribute alleged to belong to man。
（Perhaps the expression virtue； with which also the made great show；
would better mark the characteristic of his school。） The expression of
a postulate of pure practical reason might give most occasion to
misapprehension in case the reader confounded it with the
signification of the postulates in pure mathematics； which carry
apodeictic certainty with them。 These； however； postulate the
possibility of an action； the object of which has been previously
recognized a priori in theory as possible； and that with perfect
certainty。 But the former postulates the possibility of an object
itself （God and the immortality of the soul） from apodeictic practical
laws； and therefore only for the purposes of a practical reason。
This certainty of the postulated possibility then is not at all
theoretic； and consequently not apodeictic； that is to say； it is
not a known necessity as regards the object； but a necessary
supposition as regards the subject； necessary for the obedience to its
objective but practical laws。 It is； therefore； merely a necessary
hypothesis。 I could find no better expression for this rational
necessity； which is subjective； but yet true and unconditional。
In this manner； then； the a priori principles of two faculties of
the mind； the faculty of cognition and that of desire； would be
found and determined as to the conditions； extent； and limits of their
use； and thus a sure foundation be paid for a scientific system of
philosophy； both theoretic and practical。
Nothing worse could happen to these labours than that anyone
should make the unexpected discovery that there neither is； nor can
be； any a priori knowledge at all。 But there is no danger of this。
This would be the same thing as if one sought to prove by reason
that there is no reason。 For we only say that we know something by
reason； when we are conscious that we could have known it； even if
it had not been given to us in experience； hence rational knowledge
and knowledge a priori are one and the same。 It is a clear
contradiction to try to extract necessity from a principle of
experience （ex pumice aquam）； and to try by this to give a judgement
true universality （without which there is no rational inference； not
even inference from analogy； which is at least a presumed universality
and objective necessity）。 To substitute subjective necessity； that is；
custom； for objective； which exists only in a priori judgements； is to
deny to reason the power of judging about the object； i。e。； of knowing
it； and what belongs to it。 It implies； for example； that we must
not say of something which often or always follows a certain
antecedent state that we can conclude from this to that （for this
would imply objective necessity and the notion of an a priori
connexion）； but only that we may expect similar cases （just as animals
do）； that is that we reject the notion of cause altogether as false
and a mere delusion。 As to attempting to remedy this want of objective
and consequently universal validity by saying that we can see no
ground for attributing any other sort of knowledge to other rational
beings； if this reasoning were valid； our ignorance would do more
for the enlargement of our knowledge than all our meditation。 For；
then； on this very ground that we have no knowledge of any other
rational beings besides man； we should have a right to suppose them to
be of the same nature as we know ourselves to be： that is； we should
really know them。 I omit to mention that universal assent does not
prove the objective validity of a judgement （i。e。； its validity as a
cognition）；