Chapter XVI: Section II: Time (2)

=Proof that the above View of Space and Time is not a mere Hypothesis, but completely certain.=[579]--The proof, which as here recapitulated and developed follows the analytic method, has already been considered in connection with A 39 = B 56. It proceeds upon the assumption that space cannot be both an _a priori_ form of intuition and also independently real. The argument as a whole lacks clearness owing to Kant’s failure to distinguish between the problems of pure and applied geometry, between pure intuition and form of intuition. This is especially obvious in the very unfortunate and misleading second application of the triangle illustration.[580] Kant’s tendency to conceive mathematical science almost exclusively in terms of geometry is likewise illustrated.

“There is in regard to both [space and time] a large number of _a
priori_ apodictic and synthetic propositions. This is especially
true of space, which for this reason will be our chief illustration
in this enquiry.”[581]

=II. Paragraphs added in the Second Edition.=[582]--Kant proceeds to offer further proof of the ideality of the appearances (_a_) of outer and (_b_) of inner sense. Such proof he finds in the fact that these appearances consist solely of relations. (_a_) Outer appearances reduce without remainder to relations of position in intuition (_i.e._ of extension), of change of position (motion), and to the laws which express in merely relational terms the motive forces by which such change is determined. What it is that is thus present in space, or what the dynamic agencies may be to which the motion is due, is never revealed. But a real existent (_Sache an sich_) can never be known through mere relations. Outer sense consequently reveals through its representations only the relation of an object to the subject, not the intrinsic inner nature of the object in itself (_Object an sich_). Kant’s avoidance of the term _Ding an sich_ may be noted.[583]

(_b_) The same holds true of inner sense, not only because the representations of outer sense constitute its proper (_eigentlichen_) material, but also because time, in which these are set, contains only relations of succession, coexistence, and duration. This time (which as consisting only of relations can be nothing but a form[584]) is itself, in turn, a mere relation. It is only the manner in which through its own activity the mind is affected by itself. But in order to be affected by itself it must have receptivity, in other words, sensibility. Time, consequently, must be regarded as the form of this inner sense.

That everything represented in time, like that which is represented in space, consists solely of relations, Kant does not, however, attempt to prove. He is satisfied with repeating the conclusion reached in the first edition of the _Aesthetic_, that, as time is the object of a sense, it must of necessity be appearance. This, like everything which Kant wrote upon inner sense, is profoundly unsatisfactory. The obscurities of his argument are not to be excused on the ground that “the difficulty, how a subject can have an internal intuition of itself, is common to every theory.” For no great thinker,[585] except Locke, has attempted to interpret inner consciousness on the analogy of the senses. Discussion of the doctrine must meantime be deferred.[586]

=III. B 69.=--Kant here formulates the important distinction between appearance (_Erscheinung_) and illusion (_Schein_). The main text is clear so far as it goes; but the appended note is thoroughly confused. Together they contain no less than three distinct and conflicting views of illusion.[587] According to the main text, _Schein_ signifies a representation, such as may occur in a dream, to which nothing real corresponds. _Erscheinung_, on the other hand, is always the appearance of a _given_ object; but since the qualities of that object depend solely on our mode of intuition, we have to distinguish the object as appearance from the object as thing in itself.

”[Every appearance] has two sides, the one by which the object is
viewed in and by itself, ... the other by which the form of the
intuition of the object is taken into account....”[588]

Obviously, when illusion is defined in the above manner, the assertion that objects in space are mere appearances cannot be taken as meaning that they are illusory.

But this view of illusion is peculiar to the passage before us and to A 38 = B 55. It occurs nowhere else, either in the _Critique_ or in the _Prolegomena_; and it is not, as Kant has himself admitted,[589] really relevant to the purposes of the _Critique_. The issues are more adequately faced in the appended note, which, however, at the same time, shows very clearly that Kant has not yet properly disentangled their various strands. The above definition of appearance is too wide. It covers illusory sense perception as well as appearance proper. The further qualification must be added, that the predicates of appearance are constant and are inseparable from its representation. Thus the space predicates can be asserted of any external object. Redness and scent can be ascribed to the rose. All of these are genuine appearances. If, on the other hand, the two handles, as observed by Galileo, are attributed to Saturn, roundness to a distant square tower, bentness to a straight stick inserted in water, the result is mere illusion. The predicates, in such cases, do not stand the test of further observation or of the employment of other senses. Only in a certain position of its rings, relatively to the observer, does Saturn _seem_ (_scheint_) to have two handles. The distant tower only _seems_ to be round. The stick only _seems_ to be bent. But the rose _is_ extended and _is_ red. Obviously Kant is no longer viewing _Schein_ as equivalent to a merely mental image. It now receives a second meaning. It is illusion in the modern, psychological sense. It signifies an abnormal perception of an actually present object. The distinction between appearance and illusion is now reduced to a merely relative difference in constancy and universality of appearance. Saturn necessarily appears to Galileo as possessing two handles. A square tower viewed from the distance cannot appear to the human eye otherwise than round. A stick inserted in water must appear bent. If, however, Saturn be viewed under more favourable conditions, if the distance from the tower be diminished, if the stick be removed from the water, the empirical object will appear in a manner more in harmony with the possible or actual experiences of touch. The distinction is practical, rather than theoretical, in its justification. It says only that certain sets of conditions may be expected to remain uniform; those, for instance, physical, physiological, and psychical, which cause a rose to appear red. Other sets of conditions, such as those which cause the stick to appear bent, are exceptional, and for that reason the bentness may be discounted as illusion. Among the relatively constant are the space and time properties of bodies. To employ the terms of the main text, it is not only by illusion that bodies seem to exist outside me; they actually are there.

So long as we keep to the sphere of ordinary experience, and require no greater exactitude than practical life demands, this distinction is, of course, both important and valid. But Kant, by his references to Saturn, raises considerations which, if faced, must complicate the problem and place it upon an entirely different plane. If, in view of scientific requirements, the conditions of observation are more rigorously formulated, and if by artificial instruments of scientific precision we modify the perceptions of our human senses, what before was ranked as appearance becomes illusion; and no limit can be set to the transformations which even our most normal human experiences may thus be made to undergo. Even the most constant perceptions then yield to variation. The most that can be asserted is that throughout all change in the conditions of observation objects still continue to possess, in however new and revolutionary a fashion, some kind of space and time predicates. The application of this more rigorous scientific standard of appearance thus leads to a fourfold distinction between ultimate reality, scientific appearances, the appearances of ordinary consciousness, and the illusions of ordinary consciousness. The appearances of practical life are the illusions of science, and the appearances of science would similarly be illusions to any being who through ‘intuitive understanding’ could apprehend things in themselves.

But if the distinction between appearance and illusion is thus merely relative to the varying nature of the conditions under which observation takes place, it can afford no sufficient answer to the criticisms which Kant is here professing to meet. Kant has in view those critics (such as Lambert, Mendelssohn, and Garve) who had objected that if bodies in space are representations existing, as he so often asserts, only “within us,” their appearing to exist “outside us” is a complete illusion. These critics have, indeed, found a vulnerable point in Kant’s teaching. The only way in which he can effectively meet it is by frank recognition and development of the phenomenalism with which his subjectivism comes into so frequent conflict.[590] That certain perceptions are more constant than others does not prove that all alike may not be classed as illusory. The criticism concerns only the reality of extended objects. From Kant’s own extreme subjectivist position they _are_ illusions of the most thoroughgoing kind. If, as Kant so frequently maintains, objects are representations and exist only “within us,” their existence “outside us” must be denied. The criticism can be met only if Kant is prepared consistently to formulate and defend his own alternative teaching, that sensations arise through the action of external objects upon the sense-organs, and that the world of physical science has consequently a reality not reducible to mere representations in the individual mind.

It may be objected that Kant has in the main text cited one essential difference between his position and that which is being ascribed to him. Extended objects, though mere representations, are yet due to, and conditioned by, things in themselves. They are illusory only in regard to their properties, not in regard to their existence. But this distinction is not really relevant. The criticism, as just stated, is directed only against Kant’s view of space. The fact that the spatial world is a grounded and necessary illusion is not strictly relevant to the matter in dispute. Kant has, indeed, elsewhere, himself admitted the justice of the criticism. In A 780 = B 808 he cites as a possible hypothesis, entirely in harmony with his main results, though not in any degree established by them, the view

“that this life is an appearance only, that is, a sensuous
representation of purely spiritual life, and that the whole
sensible world is a mere image (_ein blosses Bild_) which hovers
before our present mode of knowledge, and like a dream has in
itself no objective reality.”

Kant’s reply is thus really only verbal. He claims that illusion, if constant, has earned the right to be called appearance. He accepts the criticism, but restates it in his own terms. The underlying phenomenalism which colours the position in his own thoughts, and for which he has not been able to find any quite satisfactory formulation, is the sole possible justification, if any such exists, for his contention that the criticism does not apply. Such phenomenalism crops out in the sentence, already partially quoted:

“If I assert that the quality of space and time, according to
which, as a condition of their existence, I posit both external
objects and my own soul, lies in my mode of intuition and not in
these objects in themselves, I am not saying that only by illusion
do bodies seem to exist outside me or my soul to be given in my
self-consciousness.”[591]

But, so far, I have simplified Kant’s argument by leaving out of account a third and entirely different view of illusion which is likewise formulated in the appended note. In the middle of the second sentence, and in the last sentence, illusion is defined as the attribution to the thing in itself of what belongs to it only in its relation to the senses. Illusion lies not in the object apprehended, but only in the _judgment_ which we pass upon it. It is due, not to sense, but to understanding.[592] Viewing illusion in this way, Kant is enabled to maintain that his critics are guilty of “an unpardonable and almost intentional misconception,”[593] since this is the very fallacy which he himself has been most concerned to attack. As he has constantly insisted, appearance is appearance just because it can never be a revelation of the thing in itself.

Now the introduction of this third view reduces the argument of the appended note to complete confusion. Its first occurrence as a parenthesis in a sentence which is stating an opposed view would seem to indicate that the note has been carelessly recast. Originally containing only a statement of the second view, Kant has connected therewith the view which he had already formulated in the first edition and in the _Prolegomena_. But the two views cannot be combined. By the former definition, illusion is necessitated but abnormal perception; according to the latter, it is a preventable error of our conscious judgment. The opposite of illusion is in the one case _appearance_, in the other _truth_. The retention of the reference to Saturn, in the statement of the third view at the end of the note, is further evidence of hasty recasting. While the rose and the extended objects are there treated as also things in themselves, Saturn is taken only in its phenomenal existence. In view of the general confusion, it is a minor inconsistency that Kant should here maintain, in direct opposition to A 28-9, that secondary qualities can be attributed to the empirical object.

This passage from the second edition is a development of _Prolegomena_, § 13, iii. Kant there employs the term appearance in a quite indefinite manner. For the most part he seems to mean by it any and every sense-experience, whether normal or abnormal, and even to include under it dream images. But it is also employed in the second of the above meanings, as signifying those sense-perceptions which harmonise with general experience. Illusion is throughout employed in the third of the above meanings. Kant’s illustration, that of the apparently retrograde movements of the planets, necessitates a distinction between apparent and real motion in space, and consequently leads to the fruitful distinction noted above. Kant gives, however, no sign that he is conscious of the complicated problems involved.

In the interval between the _Prolegomena_ (1783) and the second edition of the _Critique_ (1787) Mendelssohn had published (1785) his _Morgenstunden_. In its introduction, entitled _Vorerkenntniss von Wahrheit, Schein und Irrthum_,[594] he very carefully distinguishes between illusion (_Sinnenschein_) and error of judgment (_Irrthum_). This introduction Kant had read. In a letter to Schütz[595] he cites it by title, and praises it as “acute, original, and of exemplary clearness.” It is therefore the more inexcusable that he should again in the second edition of the _Critique_ have confused these two so radically different meanings of the term _Schein_. Mendelssohn, however, drew no distinction between _Schein_ and _Erscheinung_. They were then used as practically synonymous,[596] though of course _Schein_ was the stronger term. Kant seems to have been the first to distinguish them sharply and to attempt to define the one in opposition to the other. But the very fact that _Erscheinung_ and _Schein_ were currently employed as equivalent terms, and that the distinction, though one of his own drawing, had been mentioned only in the most cursory manner in the first edition of the _Critique_,[597] removes all justification for his retort upon his critics of “unpardonable misconception.” His anger was really due, not to the objection in itself, but to the implied comparison of his position to that of Berkeley. Such comparison never failed to arouse Kant’s wrath. For however much this accusation might be justified by his own frequent lapses into subjectivism of the most extreme type, even its partial truth was more than he was willing to admit. Berkeley represents in his eyes, not merely a subjectivist interpretation of the outer world, but the almost diametrical opposite of everything for which he himself stood. Discussion of Kant’s relation to Berkeley had best, however, be introduced through consideration of the passage immediately following in which Kant refers to Berkeley by name.

=III. (Second Part) B 70.=--Kant urges that his doctrine of the ideality of space and time, so far from reducing objects to mere illusion, is the sole means of defending their genuine reality. If space and time had an independent existence, they would have to be regarded as more real than the bodies which occupy them. For on this view space and time would continue to exist even if all their contents were removed; they would be antecedent necessary conditions of all other existences. But space and time thus interpreted are impossible conceptions.[598] The reality of bodies is thereby made to depend upon _Undinge_. If this were the sole alternative, “the good Bishop Berkeley [could] not be blamed for degrading bodies to mere illusion.” We should, Kant maintains, have to proceed still further, denying even our own existence. For had Berkeley taken account of time as well as of space, a similar argument, consistently developed in regard to time, would have constrained him to reduce the self to the level of mere illusion. Belief in the reality of things in themselves, whether spiritual or material, is defensible only if space and time be viewed as subjective. In other words, Berkeley’s idealism is an inevitable consequence of a realist view of space. But it is also its _reductio ad absurdum_.

[“Berkeley in his dogmatic idealism] maintains that space, with all
the things of which it is the inseparable condition, is something
impossible in itself, and he therefore regards the things in space
as merely imaginary entities (_Einbildungen_). Dogmatic idealism is
inevitable if space be interpreted as a property which belongs to
things in themselves. For, when so regarded, space, and everything
to which it serves as condition, is a non-entity (_Unding_). The
ground upon which this idealism rests we have removed in the
_Transcendental Aesthetic_.”[599]

The term _Schein_ is not employed throughout this passage in either of the two meanings of the appended note, but in that of the main text. It signifies a representation, to which no existence corresponds.

KANT’S RELATION TO BERKELEY

By idealism[600] Kant means any and every system which maintains that the sensible world does not exist in the form in which it presents itself to us. The position is typified in Kant’s mind by the Eleatics, by Plato, and by Descartes, all of whom are rationalists. With the denial of reality to sense-appearances they combine a belief in the possibility of rationally comprehending its supersensible basis. Failing to appreciate the true nature of the sensible, they misunderstand the character of geometrical science, and falsely ascribe to pure understanding a power of intellectual intuition. Kant’s criticisms of Berkeley show very clearly that it is this more general position which he has chiefly in view. To Berkeley Kant objects that only in sense-experience is there truth, that it is sensibility, not understanding, which possesses the power of _a priori_ intuition, and that through pure understanding, acting in independence of sensibility, no knowledge of any kind can be acquired. In other words, Kant classes Berkeley with the rationalists. And, as we have already seen, he even goes the length of regarding Berkeley’s position as the _reductio ad absurdum_ of the realist view of space. Kant does, indeed, recognise[601] that Berkeley differs from the other idealists, in holding an empirical view of space, and consequently of geometry, but this does not prevent Kant from maintaining that Berkeley’s thinking is influenced by certain fundamental implications of the realist position. Berkeley’s insight--such would seem to be Kant’s line of argument--is perverted by the very view which he is attacking. Berkeley appreciates only what is false in the Cartesian view of space; he is blind to the important element of truth which it contains. Empiricist though he be, he has no wider conception of the function and powers of sensibility than have the realists from whom he separates himself off; and in order to comprehend those existences to which alone he is willing to allow true reality, he has therefore, like the rationalists, to fall back upon pure reason.[602]

That Kant’s criticism of Berkeley should be extremely external is not, therefore, surprising. He is interested in Berkeley’s positive teaching only in so far as it enables him to illustrate the evil tendencies of a mistaken idealism, which starts from a false view of the functions of sensibility and of understanding, and of the nature of space and time. The key to the true idealism lies, he claims, in the Critical problem, how _a priori_ synthetic judgments can be possible. This is the fundamental problem of metaphysics, and until it has been formulated and answered no advance can be made.

“My so-called (Critical) idealism is thus quite peculiar in that it
overthrows ordinary idealism, and that through it alone _a priori_
cognition, even that of geometry, attains objective reality, a
thing which even the keenest realist could not assert till I had
proved the ideality of space and time.”[603]

In order to make Kant’s account of Berkeley’s teaching really comprehensible, we seem compelled to assume that he had never himself actually read any of Berkeley’s own writings. Kant’s acquaintance with the English language was most imperfect, and we have no evidence that he had ever read a single English book.[604] When he quotes Pope and Addison, he does so from German translations.[605] Subsequent to 1781 he could, indeed, have had access to Berkeley’s _Dialogues between Hylas and Philonous_[606] in a German translation; but in view of the account which he continues to give of Berkeley’s teaching, it does not seem likely[607] that he had availed himself of this opportunity. As to what the indirect sources of Kant’s knowledge of Berkeley may have been, we cannot decide with any certainty, but amongst them must undoubtedly be reckoned Hume’s statements in regard to Berkeley in the _Enquiry_,[608] and very probably also the references to Berkeley in Beattie’s _Nature of Truth_.[609] From the former Kant would learn of Berkeley’s empirical view of space and also of the sceptical tendencies of his idealist teaching. From it he might also very naturally infer that Berkeley denies all reality to objects. By Beattie Kant would be confirmed in this latter view, and also in his contention that Berkeley is unable to supply a criterion for distinguishing between reality and dreams. Kant may also have received some impressions regarding Berkeley from Hamann.

To take Kant’s criticisms of Berkeley more in detail. In the first edition of the _Critique_[610] Kant passes two criticisms, without, however, mentioning Berkeley by name: first, that he overlooks the problem of time, and, like Descartes, ascribes complete reality to the objects of inner sense. This is the cause of a second error, namely, that he views the objects of outer sense as mere illusion (_blosser Schein_). Proceeding, Kant argues that inner and outer sense are really in the same position. Though they yield only appearances, these appearances are conditioned by things in themselves. Through this relation to things in themselves they are distinguished from all merely subjective images. Berkeley is again referred to in the fourth _Paralogism_.[611] His idealism is distinguished from that of Descartes. The one is dogmatic; the other is sceptical. The one denies the existence of matter; the other only doubts whether it is possible to prove it. Berkeley claims, indeed, that there are contradictions in the very conception of matter; and Kant remarks that this is an objection which he will have to deal with in the section on the _Antinomies_. But this promise Kant does not fulfil; and doubtless for the reason that, however unwilling he may be to make the admission, on this point his own teaching, especially in the _Dialectic_, frequently coincides with that of Berkeley. So little, indeed, is Kant concerned in the first edition to defend his position against the accusation of subjectivism, that in this same section he praises the sceptical idealist as a “benefactor of human reason.”

“He compels us, even in the smallest advances of ordinary
experience, to keep on the watch, lest we consider as a well-earned
possession what we perhaps obtain only in an illegitimate manner.
We are now in a position to appreciate the value of the objections
of the idealist. They drive us by main force, unless we mean to
contradict ourselves in our commonest assertions, to view all our
perceptions, whether we call them inner or outer, as a
consciousness only of what is dependent on our sensibility. They
also compel us to regard the outer objects of these perceptions not
as things in themselves, but only as representations, of which, as
of every other representation, we can become immediately conscious,
and which are entitled outer because they depend on what we call
‘outer sense’ whose intuition is space. Space itself, however, is
nothing but an inner mode of representation in which certain
perceptions are connected with one another.”[612]

These criticisms are restated in A 491-2 = B 519-20, with the further addition that in denying the existence of extended beings “the empirical idealist” removes the possibility of distinguishing between reality and dreams. This is a new criticism. Kant is no longer referring to the denial of unknowable things in themselves. He is now maintaining that only the Critical standpoint can supply an immanent criterion whereby real experiences may be distinguished from merely subjective happenings. This point is further insisted upon in the _Prolegomena_,[613] but is nowhere developed with any direct reference to Berkeley’s own personal teaching. Kant assumes as established that any such criterion must rest upon the _a priori_; and in this connection Berkeley is conveniently made to figure as a thoroughgoing empiricist.

The _Critique_, on its publication, was at once attacked, especially in the Garve-Feder review, as presenting an idealism similar to that of Berkeley. As Erdmann has shown, the original plan of the _Prolegomena_ was largely modified in order to afford opportunity for reply to this “unpardonable and almost intentional misconception.”[614] Kant’s references to Berkeley, direct and indirect, now for the first time manifest a polemical tone, exaggerating in every possible way the difference between their points of view. Only the transcendental philosophy can establish the possibility of _a priori_ knowledge, and so it alone can afford a criterion for distinguishing between realities and dreams. It alone will account for the possibility of geometrical science; Berkeley’s idealism would render the claims of that science wholly illusory. The Critical idealism transcends experience only so far as is required to discover the conditions which make empirical cognition possible; Berkeley’s idealism is ‘visionary’ and ‘mystical.’[615] Even sceptical idealism now comes in for severe handling. It may be called “dreaming idealism”; it makes things out of mere representations, and like idealism in its dogmatic form it virtually denies the existence of the only true reality, that of things in themselves. Sceptical idealism misinterprets space by making it empirical, dogmatic idealism by regarding it as an attribute of the real. Both entirely ignore the problem of time. For these reasons they underestimate the powers of sensibility (to which space and time belong as _a priori_ forms), and exaggerate those of pure understanding.

“The position of all genuine idealists from the Eleatics to
Berkeley is contained in this formula: ‘All cognition through the
senses and experience is nothing but mere illusion, and only in the
ideas of pure understanding and Reason is there truth.’ The
fundamental principle ruling all my idealism, on the contrary, is
this: ‘All cognition of things solely from pure understanding or
pure Reason is nothing but mere illusion and only in experience is
there truth.’”[616]

This is an extremely inadequate statement of the Critical standpoint, but it excellently illustrates Kant’s perverse interpretation of Berkeley’s teaching.

To these criticisms Kant gives less heated but none the less explicit expression in the second edition of the _Critique_. He is now much more careful to avoid subjectivist modes of statement. His phenomenalist tendencies are reinforced, and come to clearer expression of all that they involve. The fourth _Paralogism_ with its sympathetic treatment of empirical idealism is omitted, and in addition to the above passage Kant inserts a new section, entitled _Refutation of Idealism_, in which he states his position in a much more adequate manner.

=IV. B 71.=--Kant continues the argument of A 39.[617] If space and time condition all existence, they will condition even divine existence, and so must render God’s omniscience, which as such must be intuitive, not discursive, difficult of conception. Upon this point Kant is more explicit in the _Dissertation_.[618]

“_Whatever is, is somewhere and sometime_, is a spurious axiom....
By this spurious principle all beings, even though they be known
intellectually, are restricted in their existence by conditions of
space and time. Philosophers therefore discuss every form of idle
question regarding the locations in the corporeal universe of
substances that are immaterial--and of which for that very reason
there can be no sensuous intuition nor any possible spatial
representation--or regarding the seat of the soul, and the like.
And since the sensuous mixes with the intellectual about as badly
as square with round, it frequently happens that the one disputant
appears as holding a sieve into which the other milks the he-goat.
The presence of immaterial things in the corporeal world is
virtual, not local, although it may conveniently be spoken of as
local. Space contains the conditions of possible interaction only
when it is between material bodies. What, however, in immaterial
substances constitutes the external relations of force between them
or between them and bodies, obviously eludes the human
intellect.... But when men reach the conception of a highest and
extra-mundane Being, words cannot describe the extent to which they
are deluded by these shades that flit before the mind. They picture
God as present in a place: they entangle Him in the world where He
is supposed to fill all space at once. They hope to make up for the
[spatial] limitation they thus impose by thinking of God’s place
_per eminentiam_, _i.e._ as infinite. But to be present in
different places at the same time is absolutely impossible, since
different places are mutually external to one another, and
consequently what is in several places is outside itself, and is
therefore present to itself outside itself--which is a
contradiction in terms. As to time, men have got into an
inextricable maze by releasing it from the laws that govern sense
knowledge, and what is more, transporting it beyond the confines of
the world to the Being that dwells there, as a condition of His
very existence. They thus torment their souls with absurd
questions, for instance, why God did not fashion the world many
centuries earlier. They persuade themselves that it is easily
possible to conceive how God may discern present things, _i.e._
what is actual in the time in which He is. But they consider that
it is difficult to comprehend how He should foresee the things
about to be, _i.e._ the actual in the time in which He is not yet.
They proceed as if the existence of the Necessary Being descended
successively through all the moments of a supposed time, and having
already exhausted part of His duration, foresaw the eternal life
that still lies before Him together with the events which [will]
occur simultaneously [with that future life of His]. All these
speculations vanish like smoke when the notion of time has been
rightly discerned.”

The references in B 71-2 to the intuitive understanding are among the many signs of Kant’s increased preoccupation, during the preparation of the second edition, with the problems which it raises. Such understanding is not sensuous, but intellectual; it is not derivative, but original; the object itself is created in the act of intuition. Or, as Kant’s position may perhaps be more adequately expressed, all of God’s activities are creative, and are inseparable from the non-sensuous intuition whereby both they and their products are apprehended by Him. Kant’s reason for again raising this point may be Mendelssohn’s theological defence of the reality of space in his _Morgenstunden_.[619] Mendelssohn has there argued that just as knowledge of independent reality is confirmed by the agreement of different senses, and is rendered the more certain in proportion to the number of senses which support the belief, so the validity of our spatial perceptions is confirmed in proportion as men are found to agree in this type of experience with one another, with the animals, and with angelic beings. Such inductive inference will culminate in the proof that even the Supreme Being apprehends things in this same spatial manner.[620] Kant’s reply is that however general the intuition of space may be among finite beings, it is sensuous and derivative, and therefore must not be predicated of a Divine Being. For obvious reasons Kant has not felt called upon to point out the inadequacy of this inductive method to the solution of Critical problems. In A 42 Kant, arguing that our forms of intuition are subjective, claims that they do not necessarily belong to all beings, though they must belong to all men.[621] He is quite consistent in now maintaining[622] that their characteristics, as sensuous and derivative, do not necessarily preclude their being the common possession of all finite beings.

THE PARADOX OF INCONGRUOUS COUNTERPARTS

The purpose, as already noted, of the above sections II. to IV., as added in the second edition, is to afford ‘confirmation’ of the ideality of space and time. That being so, it is noticeable that Kant has omitted all reference to an argument embodied, for this same purpose, in § 13 of the _Prolegomena_. The matter is of sufficient importance to call for detailed consideration.[623]

As the argument of the _Prolegomena_ is somewhat complicated, it is advisable to approach it in the light of its history in Kant’s earlier writings. It was to his teacher Martin Knutzen that Kant owed his first introduction to Newton’s cosmology; and from Knutzen he inherited the problem of reconciling Newton’s mechanical view of nature and absolute view of space with the orthodox Leibnizian tenets. In his first published work[624] Kant seeks to prove that the very existence of space is due to gravitational force, and that its three-dimensional character is a consequence of the specific manner in which gravity acts. Substances, he teaches, are unextended. Space results from the connection and order established between them by the balancing of their attractive and repulsive forces. And as the law of gravity is merely contingent, other modes of interaction, and therefore other forms of space, with more than three dimensions, must be recognised as possible.

“A science of all these possible kinds of space would undoubtedly
be the highest enterprise which a finite understanding could
undertake in the field of geometry.”[625]

In the long interval between 1747 and 1768 Kant continued to hold to some such compromise, retaining Leibniz’s view that space is derivative and relative, and rejecting Newton’s view that it is prior to, and pre-conditions, all the bodies that exist in it. But in that latter year he published a pamphlet[626] in which, following in the steps of the mathematician, Euler,[627] he drew attention to certain facts which would seem quite conclusively to favour the Newtonian as against the Leibnizian interpretation of space. The three dimensions of space are primarily distinguishable by us only through the relation in which they stand to our body. By relation to the plane that is at right angles to our body we distinguish ‘above’ and ‘below’; and similarly through the other two planes we determine what is ‘right’ and ‘left,’ ‘in front’ and ‘behind.’ Through these distinctions we are enabled to define differences which cannot be expressed in any other manner. All species of hops--so Kant maintains--wind themselves around their supports from left to right, whereas all species of beans take the opposite direction. All snail shells, with some three exceptions, turn, in descending from their apex downwards, from left to right. This determinate direction of movement, natural to each species, like the difference in spatial configuration between a right and a left hand, or between a right hand and its reflection in a mirror, involves in all cases a reference of the given object to the wider space within which it falls, and ultimately to space as a whole. Only so can its determinate character be distinguished from its opposite counterpart. For as Kant points out, though the right and the left hand are _counterparts_, that is to say, objects which have a common definition so long as the arrangement of the parts of each is determined in respect to its central line of reference, they are none the less inwardly _incongruent_, since the one can never be made to occupy the space of the other. As he adds in the _Prolegomena_, the glove of one hand cannot be used for the other hand. This inner incongruence compels us to distinguish them as different, and this difference is only determinable by location of each in a single absolute space that constrains everything within it to conform to the conditions which it prescribes. In three-dimensional space everything must have a right and a left side, and must therefore exhibit such inner differences as those just noted. Spatial determinations are not, as Leibniz teaches, subsequent to, and dependent upon, the relations of bodies to one another; it is the former that determine the latter.

“The reason why that which in the shape of a body exclusively
concerns its relation to pure space can be apprehended by us only
through its relation to other bodies, is that absolute space is not
an object of any outer sensation, but a fundamental conception
which makes all such differences possible.”[628]

Kant enforces his point by arguing that if the first portion of creation were a human hand, it would have to be either a right or a left hand. Also, a different act of creation would be demanded according as it was the one or the other. But if the hand alone existed, and there were no pre-existing space, there would be no inward difference in the relations of its parts, and nothing outside it to differentiate it. It would therefore be entirely indeterminate in nature, _i.e._ would suit either side of the body, which is impossible.

This adoption of the Newtonian view of space in 1768 was an important step forward in the development of Kant’s teaching, but could not, in view of the many metaphysical difficulties to which it leads, be permanently retained; and in the immediately following year--a year which, as he tells us,[629] “gave great light”--he achieved the final synthesis which enabled him to combine all that he felt to be essential in the opposing views. Though space is an absolute and preconditioning source of differences which are not conceptually resolvable, it is a merely subjective form of our sensibility.

Now it is significant that when Kant expounds this view in the _Dissertation_ of 1770, the argument from incongruous counterparts is no longer employed to establish the absolute and pre-conditioning character of space, but only to prove that it is a pure non-conceptual intuition.

“Which things in a given space lie towards one side, and which lie
towards the other, cannot by any intellectual penetration be
discursively described or reduced to intellectual marks. For in
solids that are completely similar and equal, but incongruent, such
as the right and the left hand (conceived solely in terms of their
extension), or spherical triangles from two opposite hemispheres,
there is a diversity which renders impossible the coincidence of
their spatial boundaries. This holds true, even though they can be
substituted for one another in all those respects which can be
expressed in marks that are capable of being made intelligible to
the mind through speech. It is therefore evident that the
diversity, that is, the incongruity, can only be apprehended by
some species of pure intuition.”[630]

There is no mention of this argument in the first edition of the _Critique_, and when it reappears in the _Prolegomena_ it is interpreted in the light of an additional premiss, and is made to yield a very different conclusion from that drawn in the _Dissertation_, and a _directly opposite conclusion_ from that drawn in 1768. Instead of being employed to establish either the intuitive character of space or its absolute existence, it is cited as evidence in proof of its subjectivity. As in 1768, it is spoken of as strange and paradoxical, and many of the previous illustrations are used. The paradox consists in the fact that bodies and spherical figures, conceptually considered, can be absolutely identical, and yet for intuition remain diverse. This paradox, Kant now maintains[631] in opposition to his 1768 argument, proves that such bodies and the space within which they fall are not independent existences. For were they things in themselves, they would be adequately cognisable through the pure understanding, and could not therefore conflict with its demands. Being conceptually identical, they would necessarily be congruent in every respect. But if space is merely the form of sensibility, the fact that in space the part is only possible through the whole will apply to everything in it, and so will generate a fundamental difference between conception and intuition.[632] Things in themselves are, as such, unconditioned, and cannot, therefore, be dependent upon anything beyond themselves. The objects of intuition, in order to be possible, must be merely ideal.

Now the new premiss which differentiates this argument from that of 1768, and which brings Kant to so opposite a conclusion, is one which is entirely out of harmony with the teaching of the _Critique_. In this section of the _Prolegomena_ Kant has unconsciously reverted to the dogmatic standpoint of the _Dissertation_, and is interpreting understanding in the illegitimate manner which he so explicitly denounces in the section on _Amphiboly_.

“The mistake ... lies in employing the understanding contrary to
its vocation transcendentally [_i.e._ transcendently] and in making
objects, _i.e._ possible intuitions, conform to concepts, not
concepts to possible intuitions, on which alone their objective
validity rests.”[633]

The question why no mention of this argument is made in the second edition of the _Critique_ is therefore answered. Kant had meantime, in the interval between 1783 and 1787,[634] become aware of the inconsistency of the position. So far from being a paradox, this assumed conflict rests upon a false view of the function of the understanding.[635] The relevant facts may serve to confirm the view of space as an intuition in which the whole precedes the parts;[636] but they can afford no evidence either of its absoluteness or of its ideality. In 1768 they seem to Kant to prove its absoluteness, only because the other alternative has not yet occurred to him. In 1783 they seem to him to prove its ideality, only because he has not yet completely succeeded in emancipating his thinking from the dogmatic rationalism of the _Dissertation_.

As already noted,[637] Kant’s reason for here asserting that space is intuitive in nature, namely, that in it the parts are conditioned by the whole, is also his reason for elsewhere describing it as an Idea of Reason. The further implication of the argument of the _Prolegomena_, that in the noumenal sphere the whole is made possible only by its unconditioned parts, raises questions the discussion of which must be deferred. The problem recurs in the _Dialectic_ in connection with Kant’s definition of the Idea of the unconditioned. In the Ideas of Reason Kant comes to recognise the existence of concepts which do not conform to the reflective type analysed by the traditional logic, and to perceive that these Ideas can yield a deeper insight than any possible to the discursive understanding. The above rationalistic assumption must not, therefore, pass unchallenged. It may be that in the noumenal sphere all partial realities are conditioned by an unconditioned whole.

* * * * *

=Concluding Paragraph.=[638]--The wording of this paragraph is in keeping with the increased emphasis which in the _Introduction_ to the second edition is given to the problem, how _a priori_ synthetic judgments are possible. Kant characteristically fails to distinguish between the problems of pure and applied mathematics, with resulting inconsecutiveness in his argumentation.

THE TRANSCENDENTAL DOCTRINE OF ELEMENTS