第 71 页

unity is purely hypothetical. It is not maintained, that this unity

does really exist, but that we must, in the interest of reason, that

is, for the establishment of principles for the various rules

presented by experience, try to discover and introduce it, so far as

is practicable, into the sphere of our cognitions.

But the transcendental employment of the understanding would lead us

to believe that this idea of a fundamental power is not problematical,

but that it possesses objective reality, and thus the systematic unity

of the various powers or forces in a substance is demanded by the

understanding and erected into an apodeictic or necessary principle.

For, without having attempted to discover the unity of the various

powers existing in nature, nay, even after all our attempts have

failed, we notwithstanding presuppose that it does exist, and may

be, sooner or later, discovered. And this reason does, not only, as in

the case above adduced, with regard to the unity of substance, but

where many substances, although all to a certain extent homogeneous,

are discoverable, as in the case of matter in general. Here also

does reason presuppose the existence of the systematic unity of

various powers- inasmuch as particular laws of nature are

subordinate to general laws; and parsimony in principles is not merely

an economical principle of reason, but an essential law of nature.

We cannot understand, in fact, how a logical principle of unity

can of right exist, unless we presuppose a transcendental principle,

by which such a systematic unit- as a property of objects

themselves- is regarded as necessary a priori. For with what right can

reason, in its logical exercise, require us to regard the variety of

forces which nature displays, as in effect a disguised unity, and to

deduce them from one fundamental force or power, when she is free to

admit that it is just as possible that all forces should be

different in kind, and that a systematic unity is not conformable to

the design of nature? In this view of the case, reason would be

proceeding in direct opposition to her own destination, by setting

as an aim an idea which entirely conflicts with the procedure and

arrangement of nature. Neither can we assert that reason has

previously inferred this unity from the contingent nature of

phenomena. For the law of reason which requires us to seek for this

unity is a necessary law, inasmuch as without it we should not possess

a faculty of reason, nor without reason a consistent and

self-accordant mode of employing the understanding, nor, in the

absence of this, any proper and sufficient criterion of empirical

truth. In relation to this criterion, therefore, we must suppose the

idea of the systematic unity of nature to possess objective validity

and necessity.

We find this transcendental presupposition lurking in different

forms in the principles of philosophers, although they have neither

recognized it nor confessed to themselves its presence. That the

diversities of individual things do not exclude identity of species,

that the various species must be considered as merely different

determinations of a few genera, and these again as divisions of

still higher races, and so on- that, accordingly, a certain systematic

unity of all possible empirical conceptions, in so far as they can

be deduced from higher and more general conceptions, must be sought

for, is a scholastic maxim or logical principle, without which

reason could not be employed by us. For we can infer the particular

from the general, only in so far as general properties of things

constitute the foundation upon which the particular rest.

That the same unity exists in nature is presupposed by

philosophers in the well-known scholastic maxim, which forbids us

unnecessarily to augment the number of entities or principles (entia

praeter necessitatem non esse multiplicanda). This maxim asserts

that nature herself assists in the establishment of this unity of

reason, and that the seemingly infinite diversity of phenomena

should not deter us from the expectation of discovering beneath this

diversity a unity of fundamental properties, of which the aforesaid

variety is but a more or less determined form. This unity, although

a mere idea, thinkers have found it necessary rather to moderate the

desire than to encourage it. It was considered a great step when

chemists were able to reduce all salts to two main genera- acids and

alkalis; and they regard this difference as itself a mere variety,

or different manifestation of one and the same fundamental material.

The different kinds of earths (stones and even metals) chemists have

endeavoured to reduce to three, and afterwards to two; but still,

not content with this advance, they cannot but think that behind these

diversities there lurks but one genus- nay, that even salts and earths

have a common principle. It might be conjectured that this is merely

an economical plan of reason, for the purpose of sparing itself

trouble, and an attempt of a purely hypothetical character, which,

when successful, gives an appearance of probability to the principle

of explanation employed by the reason. But a selfish purpose of this

kind is easily to be distinguished from the idea, according to which

every one presupposes that this unity is in accordance with the laws

of nature, and that reason does not in this case request, but

requires, although we are quite unable to determine the proper

limits of this unity.

If the diversity existing in phenomena- a diversity not of form (for

in this they may be similar) but of content- were so great that the

subtlest human reason could never by comparison discover in them the

least similarity (which is not impossible), in this case the logical

law of genera would be without foundation, the conception of a

genus, nay, all general conceptions would be impossible, and the

faculty of the understanding, the exercise of which is restricted to

the world of conceptions, could not exist. The logical principle of

genera, accordingly, if it is to be applied to nature (by which I mean

objects presented to our senses), presupposes a transcendental

principle. In accordance with this principle, homogeneity is

necessarily presupposed in the variety of phenomena (although we are

unable to determine a priori the degree of this homogeneity),

because without it no empirical conceptions, and consequently no

experience, would be possible.

The logical principle of genera, which demands identity in

phenomena, is balanced by another principle- that of species, which

requires variety and diversity in things, notwithstanding their

accordance in the same genus, and directs the understanding to

attend to the one no less than to the other. This principle (of the

faculty of distinction) acts as a check upon the reason and reason

exhibits in this respect a double and conflicting interest- on the one

hand, the interest in the extent (the interest of generality) in

relation to genera; on the other, that of the content (the interest of

individuality) in relation to the variety of species. In the former

case, the understanding cogitates more under its conceptions, in the

latter it cogitates more in them. This distinction manifests itself

likewise in the habits of thought peculiar to natural philosophers,

some of whom- the remarkably speculative heads- may be said to be

hostile to heterogeneity in phenomena, and have their eyes always

fixed on the unity of genera, while others- with a strong empirical

tendency- aim unceasingly at the analysis of phenomena, and almost

destroy in us the hope of ever being able to estimate the character of

these according to general principles.

The latter mode of thought is evidently based upon a logical

principle, the aim of which is the systematic completeness of all

cognitions. This principle authorizes me, beginning at the genus, to

descend to the various and diverse contained under it; and in this way

extension, as in the former case unity, is assured to the system.

For if we merely examine the sphere of the conception which

indicates a genus, we cannot discover how far it is possible to

proceed in the division of that sphere; just as it is impossible, from

the consideration of the space occupied by matter, to determine how

far we can proceed in the division of it. Hence every genus must

contain different species, and these again different subspecies; and

as each of the latter must itself contain a sphere (must be of a

certain extent, as a conceptus communis), reason demands that no

species or sub-species is to be considered as the lowest possible. For

a species or sub-species, being always a conception, which contains

only what is common to a number of different things, does not

completely determine any individual thing, or relate immediately to

it, and must consequently contain other conceptions, that is, other

sub-species under it. This law of specification may be thus expressed:

entium varietates non temere sunt minuendae.

But it is easy to see that this logical law would likewise be

without sense or application, were it not based upon a

transcendental law of specification, which certainly does not

require that the differences existing phenomena should be infinite

in number, for the logical principle, which merely maintains the

indeterminateness of the logical sphere of a conception, in relation

to its possible division, does not authorize this statement; while

it does impose upon the understanding the duty of searching for

subspecies to every species, and minor differences in every

difference. For, were there no lower conceptions, neither could

there be any higher. Now the understanding cognizes only by means of

conceptions; consequently, how far soever it may proceed in

division, never by mere intuition, but always by lower and lower

conceptions. The cognition of phenomena in their complete

determination (which is possible only by means of the understanding)

requires an unceasingly continued specification of conceptions, and

a progression to ever smaller differences, of which abstraction bad

been made in the conception of the species, and still more in that

of the genus.

This law of specification cannot be deduced from experience; it

can never present us with a principle of so universal an

application. Empirical specification very soon stops in its

distinction of diversities, and requires the guidance of the

transcendental law, as a principle of the reason- a law which

imposes on us the necessity of never ceasing in our search for

differences, even although these may not present themselves to the

senses. That absorbent earths are of different kinds could only be

discovered by obeying the anticipatory law of reason, which imposes

upon the understanding the task of discovering the differences

existing between these earths, and supposes that nature is richer in

substances than our senses would indicate. The faculty of the

understanding belongs to us just as much under the presupposition of

differences in the objects of nature, as under the condition that

these objects are homogeneous, because we could not possess

conceptions, nor make any use of our understanding, were not the

phenomena included under these conceptions in some respects

dissimilar, as well as similar, in their character.

Reason thus prepares the sphere of the understanding for the

operations of this faculty: 1. By the principle of the homogeneity

of the diverse in higher genera; 2. By the principle of the variety of

the homogeneous in lower species; and, to complete the systematic

unity, it adds, 3. A law of the affinity of all conceptions which

prescribes a continuous transition from one species to every other

by the gradual increase of diversity. We may term these the principles

of the homogeneity, the specification, and the continuity of forms.

The latter results from the union of the two former, inasmuch as we

regard the systematic connection as complete in thought, in the ascent

to higher genera, as well as in the descent to lower species. For

all diversities must be related to each other, as they all spring from

one highest genus, descending through the different gradations of a

more and more extended determination.

We may illustrate the systematic unity produced by the three logical

principles in the following manner. Every conception may be regarded

as a point, which, as the standpoint of a spectator, has a certain

horizon, which may be said to enclose a number of things that may be

viewed, so to speak, from that centre. Within this horizon there

must be an infinite number of other points, each of which has its

own horizon, smaller and more circumscribed; in other words, every

species contains sub-species, according to the principle of

specification, and the logical horizon consists of smaller horizons

(subspecies), but not of points (individuals), which possess no

extent. But different horizons or genera, which include under them

so many conceptions, may have one common horizon, from which, as

from a mid-point, they may be surveyed; and we may proceed thus,

till we arrive at the highest genus, or universal and true horizon,

which is determined by the highest conception, and which contains

under itself all differences and varieties, as genera, species, and

subspecies.

To this highest standpoint I am conducted by the law of homogeneity,

as to all lower and more variously-determined conceptions by the law

of specification. Now as in this way there exists no void in the whole

extent of all possible conceptions, and as out of the sphere of

these the mind can discover nothing, there arises from the

presupposition of the universal horizon above mentioned, and its

complete division, the principle: Non datur vacuum formarum. This

principle asserts that there are not different primitive and highest

genera, which stand isolated, so to speak, from each other, but all

the various genera are mere divisions and limitations of one highest

and universal genus; and hence follows immediately the principle:

Datur continuum formarum. This principle indicates that all