of cognitions of the understanding； which have a direct relation to
experience； and aims at the ideal unity of these cognitions… a unity
which far transcends all experience or empirical notions。 The affinity
of the diverse； notwithstanding the differences existing between its
parts； has a relation to things； but a still closer one to the mere
properties and powers of things。 For example； imperfect experience may
represent the orbits of the planets as circular。 But we discover
variations from this course； and we proceed to suppose that the
planets revolve in a path which； if not a circle； is of a character
very similar to it。 That is to say； the movements of those planets
which do not form a circle will approximate more or less to the
properties of a circle； and probably form an ellipse。 The paths of
ets exhibit still greater variations； for； so far as our
observation extends； they do not return upon their own course in a
circle or ellipse。 But we proceed to the conjecture that ets
describe a parabola； a figure which is closely allied to the
ellipse。 In fact； a parabola is merely an ellipse； with its longer
axis produced to an indefinite extent。 Thus these principles conduct
us to a unity in the genera of the forms of these orbits； and；
proceeding farther； to a unity as regards the cause of the motions
of the heavenly bodies… that is； gravitation。 But we go on extending
our conquests over nature； and endeavour to explain all seeming
deviations from these rules； and even make additions to our system
which no experience can ever substantiate… for example； the theory； in
affinity with that of ellipses； of hyperbolic paths of ets；
pursuing which； these bodies leave our solar system and； passing
from sun to sun； unite the most distant parts of the infinite
universe； which is held together by the same moving power。
The most remarkable circumstance connected with these principles
is that they seem to be transcendental； and； although only
containing ideas for the guidance of the empirical exercise of reason；
and although this empirical employment stands to these ideas in an
asymptotic relation alone （to use a mathematical term）； that is；
continually approximate； without ever being able to attain to them；
they possess； notwithstanding； as a priori synthetical propositions；
objective though undetermined validity； and are available as rules for
possible experience。 In the elaboration of our experience； they may
also be employed with great advantage； as heuristic* principles。 A
transcendental deduction of them cannot be made； such a deduction
being always impossible in the case of ideas； as has been already
shown。
*From the Greek； eurhioko。
We distinguished； in the Transcendental Analytic； the dynamical
principles of the understanding； which are regulative principles of
intuition； from the mathematical； which are constitutive principles of
intuition。 These dynamical laws are； however； constitutive in relation
to experience； inasmuch as they render the conceptions without which
experience could not exist possible a priori。 But the principles of
pure reason cannot be constitutive even in regard to empirical
conceptions； because no sensuous schema corresponding to them can be
discovered； and they cannot therefore have an object in concreto。 Now；
if I grant that they cannot be employed in the sphere of experience；
as constitutive principles； how shall I secure for them employment and
objective validity as regulative principles； and in what way can
they be so employed？
The understanding is the object of reason； as sensibility is the
object of the understanding。 The production of systematic unity in all
the empirical operations of the understanding is the proper occupation
of reason； just as it is the business of the understanding to
connect the various content of phenomena by means of conceptions；
and subject them to empirical laws。 But the operations of the
understanding are； without the schemata of sensibility；
undetermined； and； in the same manner； the unity of reason is
perfectly undetermined as regards the conditions under which； and
the extent to which； the understanding ought to carry the systematic
connection of its conceptions。 But； although it is impossible to
discover in intuition a schema for the plete systematic unity of
all the conceptions of the understanding； there must be some
analogon of this schema。 This analogon is the idea of the maximum of
the division and the connection of our cognition in one principle。 For
we may have a determinate notion of a maximum and an absolutely
perfect； all the restrictive conditions which are connected with an
indeterminate and various content having been abstracted。 Thus the
idea of reason is analogous with a sensuous schema； with this
difference； that the application of the categories to the schema of
reason does not present a cognition of any object （as is the case with
the application of the categories to sensuous schemata）； but merely
provides us with a rule or principle for the systematic unity of the
exercise of the understanding。 Now； as every principle which imposes
upon the exercise of the understanding a priori pliance with the
rule of systematic unity also relates； although only in an indirect
manner； to an object of experience； the principles of pure reason will
also possess objective reality and validity in relation to experience。
But they will not aim at determining our knowledge in regard to any
empirical object； they will merely indicate the procedure； following
which the empirical and determinate exercise of the understanding
may be in plete harmony and connection with itself… a result
which is produced by its being brought into harmony with the principle
of systematic unity； so far as that is possible； and deduced from it。
I term all subjective principles； which are not derived from
observation of the constitution of an object； but from the interest
which Reason has in producing a certain pleteness in her
cognition of that object； maxims of reason。 Thus there are maxims of
speculative reason； which are based solely upon its speculative
interest； although they appear to be objective principles。
When principles which are really regulative are regarded as
constitutive； and employed as objective principles； contradictions
must arise； but if they are considered as mere maxims； there is no
room for contradictions of any kind； as they then merely indicate
the different interests of reason； which occasion differences in the
mode of thought。 In effect； Reason has only one single interest； and
the seeming contradiction existing between her maxims merely indicates
a difference in； and a reciprocal limitation of； the methods by
which this interest is satisfied。
This reasoner has at heart the interest of diversity… in
accordance with the principle of specification； another； the
interest of unity… in accordance with the principle of aggregation。
Each believes that his judgement rests upon a thorough insight into
the subject he is examining； and yet it has been influenced solely
by a greater or less degree of adherence to some one of the two
principles； neither of which are objective； but originate solely
from the interest of reason； and on this account to be termed maxims
rather than principles。 When I observe intelligent men disputing about
the distinctive characteristics of men； animals； or plants； and even
of minerals； those on the one side assuming the existence of certain
national characteristics； certain well…defined and hereditary
distinctions of family； race； and so on； while the other side maintain
that nature has endowed all races of men with the same faculties and
dispositions； and that all differences are but the result of
external and accidental circumstances… I have only to consider for a
moment the real nature of the subject of discussion； to arrive at
the conclusion that it is a subject far too deep for us to judge of；
and that there is little probability of either party being able to
speak from a perfect insight into and understanding of the nature of
the subject itself。 Both have； in reality； been struggling for the
twofold interest of reason； the one maintaining the one interest；
the other the other。 But this difference between the maxims of
diversity and unity may easily be reconciled and adjusted； although；
so long as they are regarded as objective principles； they must
occasion not only contradictions and polemic； but place hinderances in
the way of the advancement of truth； until some means is discovered of
reconciling these conflicting interests； and bringing reason into
union and harmony with itself。
The same is the case with the so…called law discovered by
Leibnitz； and supported with remarkable ability by Bonnet… the law
of the continuous gradation of created beings； which is nothing more
than an inference from the principle of affinity； for observation
and study of the order of nature could never present it to the mind as
an objective truth。 The steps of this ladder； as they appear in
experience； are too far apart from each other； and the so…called petty
differences between different kinds of animals are in nature
m