r special
modes of existing. Alteration, _i.e._, origin and extinction, is true of
states only, which can begin and cease to be, and not of substances, which
change (_sich veraendern_), i.e., pass from one mode of existence into
another, but do not alter (_wechseln_), i.e., pass from non-existence into
existence, or the reverse. It is the permanent alone that changes, and
its states alone that begin and cease to be. The origin and extinction of
substances, or the increase and diminution of their quantum, would remove
the sole condition of the empirical unity of time; for the time relations
of the coexistent and the successive can be perceived only in an identical
substratum, in a permanent, which exists always. The law "From nothing
nothing comes, and nothing can return to nothing," is everywhere assumed
and has been frequently advanced, but never yet proved, for, indeed, it is
impossible to prove it dogmatically. Here the only possible proof for it,
the critical proof, is given: the principle of permanence is a necessary
condition of experience. The same argument establishes the principle of
sufficient reason, and the principle of the community of substances,
together with the unity of the world to be inferred from this. The three
Analogies together assert: "All phenomena exist in one nature and must so
exist, because without such a unity _a priori_ no unity of experience,
and therefore no determination of objects in experience, would be
possible."--In connection with the Postulates the same transcendental proof
is given for a series of other laws of nature _a priori_, viz., that in the
course of the changes in the world--for the causal principle holds only for
effects in nature, not for the existence of things as substances--there
can be neither blind chance nor a blind necessity (but only a conditional,
hence an intelligible, necessity); and, further, that in the series of
phenomena, there can be neither leap, nor gap, nor break, and hence no
void--_in mundo non datur casus, non datur fatum, non datur saltus, non
datur hiatus_.

While the dynamical principles have to do with the relation of phenomena,
whether it be to one another (Analogies), or to our faculty of cognition
(Postulates), the mathematical relate to the quantity of intuitions and
sensations, and furnish the basis for the application of mathematics
to natural science.[1] An extensive quantity is one in which the
representation of the parts makes the repre