conception of substance。 As I do not wish this critical essay； the
sole purpose of which is to treat of the sources of our synthetical
cognition a priori； to be crowded with analyses which merely
explain； but do not enlarge the sphere of our conceptions； I reserve
the detailed explanation of the above conceptions for a future
system of pure reason。 Such an analysis； indeed； executed with great
particularity； may already be found in well…known works on this
subject。 But I cannot at present refrain from making a few remarks
on the empirical criterion of a substance； in so far as it seems to be
more evident and more easily recognized through the conception of
action than through that of the permanence of a phenomenon。
Where action （consequently activity and force） exists； substance
also must exist； and in it alone must be sought the seat of that
fruitful source of phenomena。 Very well。 But if we are called upon
to explain what we mean by substance； and wish to avoid the vice of
reasoning in a circle； the answer is by no means so easy。 How shall we
conclude immediately from the action to the permanence of that which
acts； this being nevertheless an essential and peculiar criterion of
substance （phenomenon）？ But after what has been said above； the
solution of this question bees easy enough； although by the
mon mode of procedure… merely analysing our conceptions… it would
be quite impossible。 The conception of action indicates the relation
of the subject of causality to the effect。 Now because all effect
consists in that which happens； therefore in the changeable； the
last subject thereof is the permanent； as the substratum of all that
changes； that is； substance。 For according to the principle of
causality； actions are always the first ground of all change in
phenomena and； consequently； cannot be a property of a subject which
itself changes； because if this were the case； other actions and
another subject would be necessary to determine this change。 From
all this it results that action alone； as an empirical criterion； is a
sufficient proof of the presence of substantiality； without any
necessity on my part of endeavouring to discover the permanence of
substance by a parison。 Besides； by this mode of induction we could
not attain to the pleteness which the magnitude and strict
universality of the conception requires。 For that the primary
subject of the causality of all arising and passing away； all origin
and extinction； cannot itself （in the sphere of phenomena） arise and
pass away； is a sound and safe conclusion； a conclusion which leads us
to the conception of empirical necessity and permanence in
existence； and consequently to the conception of a substance as
phenomenon。
When something happens； the mere fact of the occurrence； without
regard to that which occurs； is an object requiring investigation。 The
transition from the non…being of a state into the existence of it；
supposing that this state contains no quality which previously existed
in the phenomenon； is a fact of itself demanding inquiry。 Such an
event； as has been shown in No。 A； does not concern substance （for
substance does not thus originate）； but its condition or state。 It
is therefore only change； and not origin from nothing。 If this
origin be regarded as the effect of a foreign cause； it is termed
creation； which cannot be admitted as an event among phenomena；
because the very possibility of it would annihilate the unity of
experience。 If； however； I regard all things not as phenomena； but
as things in themselves and objects of understanding alone； they；
although substances； may be considered as dependent； in respect of
their existence； on a foreign cause。 But this would require a very
different meaning in the words； a meaning which could not apply to
phenomena as objects of possible experience。
How a thing can be changed； how it is possible that upon one state
existing in one point of time； an opposite state should follow in
another point of time… of this we have not the smallest conception a
priori。 There is requisite for this the knowledge of real powers；
which can only be given empirically； for example； knowledge of
moving forces； or； in other words； of certain successive phenomena （as
movements） which indicate the presence of such forces。 But the form of
every change； the condition under which alone it can take place as the
ing into existence of another state （be the content of the
change； that is； the state which is changed； what it may）； and
consequently the succession of the states themselves can very well
be considered a priori； in relation to the law of causality and the
conditions of time。*
*It must be remarked that I do not speak of the change of certain
relations； but of the change of the state。 Thus； when a body moves
in a uniform manner； it does not change its state （of motion）； but
only when all motion increases or decreases。
When a substance passes from one state； a； into another state； b；
the point of time in which the latter exists is different from； and
subsequent to that in which the former existed。 In like manner； the
second state； as reality （in the phenomenon）； differs from the
first； in which the reality of the second did not exist； as b from
zero。 That is to say； if the state； b； differs from the state； a； only
in respect to quantity； the change is a ing into existence of b …
a； which in the former state did not exist； and in relation to which
that state is = O。
Now the question arises how a thing passes from one state = a；
into another state = b。 Between two moments there is always a
certain time； and between two states existing in these moments there
is always a difference having a certain quantity （for all parts of
phenomena are in their turn quantities）。 Consequently； every
transition from one state into another is always effected in a time
contained between two moments； of which the first determines the state
which leaves； and the second determines the state into the thing
passes。 the thing leaves； and the second determines the state into
which the thing Both moments； then； are limitations of the time of a
change； consequently of the intermediate state between both； and as
such they belong to the total of the change。 Now every change has a
cause； which evidences its causality in the whole time during which
the charge takes place。 The cause； therefore； does not produce the
change all at once or in one moment； but in a time； so that； as the
time gradually increases from the mencing instant； a； to its
pletion at b； in like manner also； the quantity of the reality
（b … a） is generated through the lesser degrees which are contained
between the first and last。 All change is therefore possible only
through a continuous action of the causality； which； in so far as it
is uniform； we call a momentum。 The change does not consist of these
momenta； but is generated or produced by them as their effect。
Such is the law of the continuity of all change； the ground of which
is that neither time itself nor any phenomenon in time consists of
parts which are the smallest possible； but that； notwithstanding；
the state of a thing passes in the process of a change through all
these parts； as elements； to its second state。 There is no smallest
degree of reality in a phenomenon； just as there is no smallest degree
in the quantity of time； and so the new state of reality grows up
out of the former state； through all the infinite degrees thereof； the
differences of which one from another； taken all together； are less
than the difference between o and a。
It is not our business to inquire here into the utility of this
principle in the investigation of nature。 But how such a
proposition； which appears so greatly to extend our knowledge of
nature； is possible pletely a priori； is indeed a question which
deserves investigation； although the first view seems to demonstrate
the truth and reality of the principle； and the question； how it is
possible； may be considered superfluous。 For there are so many
groundless pretensions to the enlargement of our knowledge by pure
reason that we must take it as a general rule to be mistrustful of all
such； and without a thoroughgoing and radical deduction； to believe
nothing of the sort even on the clearest dogmatical evidence。
Every addition to our empirical knowledge； and every advance made in
the exercise of our perception； is nothing more than an extension of
the determination of the internal sense； that is to say； a progression
in time； be objects themselves what they may； phenomena； or pure
intuitions。 This progression in time determines everything； and is
itself determined by nothing else。 That is to say； the parts of the
progression exist only in time； and by means of the synthesis thereof；
and are not given antecedently to it。 For this reason； every
transition in perception to anything which follows upon another in
time； is a determination of time by means of the production of this
perception。 And as this determination of time is； always and in all
its parts； a quantity； the perception produced is to be considered
as a quantity which proceeds through all its degrees… no one of
which is the smallest possible… from zero up to its determined degree。
From this we perceive the possibility of cognizing a priori a law of
changes… a law； however； which concerns their form merely。 We merely
anticipate our own apprehension； the formal condition of which；
inasmuch as it is itself to be found in the mind antecedently to all
given phenomena； must certainly be capable of being cognized a priori。
Thus； as time contains the sensuous condition a priori of the
possibility of a continuous progression of that which exists to that
which follows it； the understanding； by virtue of the unity of
apperception； contains the condition a priori of the possibility of
a continuous determination of the position in time of all phenomena；
and this by means of the series of causes and effects； the former of
which necessitate the sequence of the latter； and thereby render
universally and for all time； and by consequence； objectively； valid
the empirical cognition of the relations of time。