fail to find the additional form of unity we expected； but we do not
lose the rational unity which the mind requires in its procedure in
experience。 But even a miscarriage of this sort cannot affect the
law in its general and teleological relations。 For although we may
convict an anatomist of an error； when he connects the limb of some
animal with a certain purpose； it is quite impossible to prove in a
single case that any arrangement of nature； be it what it may； is
entirely without aim or design。 And thus medical physiology； by the
aid of a principle presented to it by pure reason； extends its very
limited empirical knowledge of the purposes of the different parts
of an organized body so far that it may be asserted with the utmost
confidence； and with the approbation of all reflecting men； that every
organ or bodily part of an animal has its use and answers a certain
design。 Now； this is a supposition which； if regarded as of a
constitutive character； goes much farther than any experience or
observation of ours can justify。 Hence it is evident that it is
nothing more than a regulative principle of reason； which aims at
the highest degree of systematic unity； by the aid of the idea of a
causality according to design in a supreme cause… a cause which it
regards as the highest intelligence。
*The advantages which a circular form； in the case of the earth； has
over every other； are well known。 But few are aware that the slight
flattening at the poles； which gives it the figure of a spheroid； is
the only cause which prevents the elevations of continents or even
of mountains； perhaps thrown up by some internal convulsion； from
continually altering the position of the axis of the earth… and that
to some considerable degree in a short time。 The great protuberance of
the earth under the Equator serves to overbalance the impetus of all
other masses of earth； and thus to preserve the axis of the earth；
so far as we can observe； in its present position。 And yet this wise
arrangement has been unthinkingly explained from the equilibrium of
the formerly fluid mass。
If； however； we neglect this restriction of the idea to a purely
regulative influence； reason is betrayed into numerous errors。 For
it has then left the ground of experience； in which alone are to be
found the criteria of truth； and has ventured into the region of the
inprehensible and unsearchable； on the heights of which it loses
its power and collectedness； because it has pletely severed its
connection with experience。
The first error which arises from our employing the idea of a
Supreme Being as a constitutive （in repugnance to the very nature of
an idea）； and not as a regulative principle； is the error of
inactive reason （ignava ratio）。* We may so term every principle
which requires us to regard our investigations of nature as absolutely
plete； and allows reason to cease its inquiries； as if it had fully
executed its task。 Thus the psychological idea of the ego； when
employed as a constitutive principle for the explanation of the
phenomena of the soul； and for the extension of our knowledge
regarding this subject beyond the limits of experience… even to the
condition of the soul after death… is convenient enough for the
purposes of pure reason； but detrimental and even ruinous to its
interests in the sphere of nature and experience。 The dogmatizing
spiritualist explains the unchanging unity of our personality
through all changes of condition from the unity of a thinking
substance； the interest which we take in things and events that can
happen only after our death； from a consciousness of the immaterial
nature of our thinking subject； and so on。 Thus he dispenses with
all empirical investigations into the cause of these internal
phenomena； and with all possible explanations of them upon purely
natural grounds； while； at the dictation of a transcendent reason；
he passes by the immanent sources of cognition in experience；
greatly to his own ease and convenience； but to the sacrifice of
all； genuine insight and intelligence。 These prejudicial
consequences bee still more evident； in the case of the
dogmatical treatment of our idea of a Supreme Intelligence； and the
theological system of nature （physico…theology） which is falsely based
upon it。 For； in this case； the aims which we observe in nature； and
often those which we merely fancy to exist； make the investigation
of causes a very easy task； by directing us to refer such and such
phenomena immediately to the unsearchable will and counsel of the
Supreme Wisdom； while we ought to investigate their causes in the
general laws of the mechanism of matter。 We are thus remended to
consider the labour of reason as ended； when we have merely
dispensed with its employment； which is guided surely and safely
only by the order of nature and the series of changes in the world…
which are arranged according to immanent and general laws。 This
error may be avoided； if we do not merely consider from the view…point
of final aims certain parts of nature； such as the division and
structure of a continent； the constitution and direction of certain
mountain…chains； or even the organization existing in the vegetable
and animal kingdoms； but look upon this systematic unity of nature
in a perfectly general way； in relation to the idea of a Supreme
Intelligence。 If we pursue this advice； we lay as a foundation for all
investigation the conformity to aims of all phenomena of nature in
accordance with universal laws； for which no particular arrangement of
nature is exempt； but only cognized by us with more or less
difficulty； and we possess a regulative principle of the systematic
unity of a teleological connection； which we do not attempt to
anticipate or predetermine。 All that we do； and ought to do； is to
follow out the physico…mechanical connection in nature according to
general laws； with the hope of discovering； sooner or later； the
teleological connection also。 Thus； and thus only； can the principle
of final unity aid in the extension of the employment of reason in the
sphere of experience； without being in any case detrimental to its
interests。
*This was the term applied by the old dialecticians to a sophistical
argument； which ran thus： If it is your fate to die of this disease；
you will die； whether you employ a physician or not。 Cicero says
that this mode of reasoning has received this appellation； because； if
followed； it puts an end to the employment of reason in the affairs of
life。 For a similar reason； I have applied this designation to the
sophistical argument of pure reason。
The second error which arises from the misconception of the
principle of systematic unity is that of perverted reason （perversa
ratio； usteron roteron rationis）。 The idea of systematic unity is
available as a regulative principle in the connection of phenomena
according to general natural laws； and； how far soever we have to
travel upon the path of experience to discover some fact or event；
this idea requires us to believe that we have approached all the
more nearly to the pletion of its use in the sphere of nature；
although that pletion can never be attained。 But this error
reverses the procedure of reason。 We begin by hypostatizing the
principle of systematic unity； and by giving an anthropomorphic
determination to the conception of a Supreme Intelligence； and then
proceed forcibly to impose aims upon nature。 Thus not only does
teleology； which ought to aid in the pletion of unity in accordance
with general laws； operate to the destruction of its influence； but it
hinders reason from attaining its proper aim； that is； the proof； upon
natural grounds； of the existence of a supreme intelligent cause。 For；
if we cannot presuppose supreme finality in nature a priori； that
is； as essentially belonging to nature； how can we be directed to
endeavour to discover this unity and； rising gradually through its
different degrees； to approach the supreme perfection of an author
of all… a perfection which is absolutely necessary； and therefore
cognizable a priori？ The regulative principle directs us to presuppose
systematic unity absolutely and； consequently； as following from the
essential nature of things… but only as a unity of nature； not
merely cognized empirically； but presupposed a priori； although only
in an indeterminate manner。 But if I insist on basing nature upon
the foundation of a supreme ordaining Being； the unity of nature is in
effect lost。 For； in this case； it is quite foreign and unessential to
the nature of things； and cannot be cognized from the general laws
of nature。 And thus arises a vicious circular argument； what ought
to have been proved having been presupposed。
To take the regulative principle of systematic unity in nature for a
constitutive principle； and to hypostatize and make a cause out of
that which is properly the ideal ground of the consistent and
harmonious exercise of reason； involves reason in inextricable
embarrassments。 The investigation of nature pursues its own path under
the guidance of the chain of natural causes； in accordance with the
general laws of nature； and ever follows the light of