Chapter XV: Section II: Time (1)

METAPHYSICAL EXPOSITION OF THE CONCEPTION OF TIME

=Time: First Argument.=--This argument is in all respects the same as the first argument on space. The thesis is that the representation[491] of time is not of empirical origin. The proof is based on the fact that this representation must be previously given in order that the perception of coexistence or succession be possible. It also runs on all fours with the first argument in the _Dissertation_.

“_The idea of time does not originate in, but is presupposed by the
senses._ When a number of things act upon the senses, it is only by
means of the idea of time that they can be represented whether as
simultaneous or as successive. Nor does succession generate the
conception of time; but stimulates us to form it. Thus the notion
of time, even if acquired through experience, is very badly defined
as being a series of actual things existing one _after_ another.
For I can understand what the word _after_ signifies only if I
already know what time means. For those things are _after_ one
another which exist at _different_ times, as those are
_simultaneous_ which exist at one and the same time.”[492]

=Second Argument.=--Kant again applies to time the argument already employed by him in dealing with space. The thesis is that time is given _a priori_. Proof is found in the fact that it cannot be thought away, _i.e._ in the fact of its subjective necessity. From this subjective necessity follows its objective necessity, so far as all appearances are concerned. In the second edition Kant added a phrase--“as the general condition of their possibility”--which is seriously misleading. The concluding sentence is thereby made to read as if Kant were arguing from the objective necessity of time, _i.e._ from its necessity as a constituent in the appearances apprehended, to its apriority. It is indeed possible that Kant himself regarded this objective necessity of time as contributing to the proof of its apriority. But no such argument can be accepted. Time may be necessary to appearances, _once appearances are granted_. This does not, however, prove that it must therefore precede them _a priori_. This alteration in the second edition is an excellent, though unfortunate, example of Kant’s invincible carelessness in the exposition of his thought. It has contributed to a misreading by Herbart and others of this and of the corresponding argument on space.

“Let us not talk of an absolute space as the presupposition of all
our constructed figures. Possibility is nothing but thought, and it
arises only when it is thought. Space is nothing but possibility,
for it contains nothing save images of the existent; and absolute
space is nothing save the abstracted general possibility of such
constructions, abstracted from it after completion of the
construction. The necessity of the representation of space ought
never to have played any rôle in philosophy. To think away space is
to think away the _possibility_ of that which has been previously
posited as _actual_. Obviously that is impossible, and the opposite
is necessary.”[493]

Were Kant really arguing here and in the second argument on space solely from the _objective_ necessity of time and space, this criticism would be unanswerable. But even taking the argument in its first edition form, as an argument from the _psychological_ necessity of time, it lies open to the same objection as the argument on space. It rests upon a false statement of fact. We cannot retain time in the absence of all appearances of outer and inner sense. With the removal of the given manifold, time itself must vanish.

=Fourth Argument.=[494]--This argument differs only slightly, and mainly through omissions,[495] from the fourth[496] of the arguments in regard to space; but a few minor points call for notice. (_a_) In the first sentence, instead of intuition, which alone is under consideration in its contrast to conception, Kant employs the phrase “pure form of intuition.” (_b_) In the third sentence Kant uses the quite untenable phrase “given through a single object (_Gegenstand_).” Time is not given from without, nor is it due to an object. (_c_) The concluding sentences properly belong to the transcendental exposition. They are here introduced, not in the ambiguous manner of the fourth[1] argument on space, but explicitly as a further argument in proof of the intuitive character of time. The synthetic proposition which Kant cites is taken neither from the science of motion nor from arithmetic. It expresses the nature of time itself, and for that reason is immediately contained in the intuition of time.

=Fifth Argument.=--This argument differs fundamentally from the corresponding argument on space, whether of the first or of the second edition, and must therefore be independently analysed. The thesis is again that time is an intuition. Proof is derived from the fact that time is a representation in which the parts arise only through limitation, and in which, therefore, the whole must precede the parts. The original (_ursprüngliche_) time-representation, _i.e._ the fundamental representation through limitation of which the parts arise as secondary products, must be an intuition.

To this argument Kant makes two explanatory additions. (_a_) As particular times arise through limitation of one single time, time must in its original intuition be given as infinite, _i.e._ as unlimited. The infinitude of time is not, therefore, as might seem to be implied by the prominence given to it, and by analogy with the final arguments of both the first and the second edition, a part of the proof that it is an intuition, but only a consequence of the feature by which its intuitive character is independently established. The unwary reader, having in mind the corresponding argument on space, is almost inevitably misled. All reference to infinitude could, so far as this argument is concerned, have been omitted. The mode in which the argument opens seems indeed to indicate that Kant was not himself altogether clear as to the cross-relations between the arguments on space and time respectively. The real parallel to this argument is to be found in the second part of the fourth[1] argument on space. That part was omitted by Kant in his fourth argument on time, and is here developed into a separate argument. This is, of course, a further cause of confusion to the reader, who is not prepared for such arbitrary rearrangement. Indeed it is not surprising to find that when Kant became the reader of his own work, in preparing it for the second edition, he was himself misled by the intricate perversity of his exposition. In re-reading the argument he seems to have forgotten that it represents the second part of the fourth[497] argument on space. Interpreting it in the light of the fifth[498] argument on space which he had been recasting for the second edition, it seemed to him possible, by a slight alteration, to bring this argument on time into line with that new proof.[499] This unfortunately results in the perverting of the entire paragraph. The argument demands an opposition between intuition in which the whole precedes the parts, and conception in which the parts precede the whole. In order to bring the opposition into line with the new argument on space, according to which a conception contains an infinite number of parts, not in it, but only under it, Kant substitutes for the previous parenthesis the statement that “concepts contain only partial representations,” meaning, apparently, that their constituent elements are merely abstracted attributes, not real concrete parts, or in other words, not strictly parts at all, but only partial representations. But this does not at all agree with the context. The point at issue is thereby obscured.

(_b_) The main argument rests upon and presupposes a very definite view as to the manner in which alone, according to Kant, concepts are formed. Only if this view be granted as true of all concepts without exception is the argument cogent. This doctrine[500] of the concept is accordingly stated by Kant in the words of the parenthesis. The partial representations, _i.e._ the different properties which go to constitute the object or content conceived, precede the representation of the whole. “The aggregation of co-ordinate attributes (_Merkmale_) constitutes the totality of the concept.”[501] Upon the use which Kant thus makes of the traditional doctrine of the concept, and upon its lack of consistency with his recognition of relational categories, we have already dwelt.[502]

=Third Argument and the Transcendental Exposition.=--The third argument ought to have been omitted in the second edition, and its substance incorporated in the new transcendental exposition, as was done with the corresponding argument concerning space. The excuse which Kant offers for not making the change, namely, his desire for brevity, is not valid. By insertion in the new section the whole matter could have been stated just as briefly as before.

The purpose of the transcendental exposition has been already defined. It is to show how time, when viewed in the manner required by the results of the metaphysical deduction, as an _a priori_ intuition, renders synthetic _a priori_ judgments possible.

This exposition, as it appears in the third argument of the first edition, grounds the apodictic character of two axioms in regard to time[503] on the proved apriority of the representation of time, and then by implication finds in these axioms a fresh proof of the apriority of time.

The new transcendental exposition extends the above by two further statements: (_a_) that only through the intuition of time can any conception of change, and therewith of motion (as change of place), be formed; and (_b_) that it is because the intuition of time is an _a priori_ intuition that the synthetic _a priori_ propositions of the “general doctrine of motion” are possible. To take each in turn. (_a_) Save by reference to time the conception of motion is self-contradictory. It involves the ascription to one and the same thing of contradictory predicates, _e.g._ that an object both is and is not in a certain place. From this fact, that time makes possible what is not possible in pure conception, Kant, in his earlier rationalistic period, had derived a proof of the subjectivity of time.[504] (_b_) In 1786 in the _Metaphysical First Principles of Natural Science_ Kant had developed the fundamental principles of the general science of motion. He takes the opportunity of the second edition (1787) of the _Critique_ to assign this place to them in his general system. The implication is that the doctrine of motion stands to time in the relation in which geometry stands to space. Kant is probably here replying, as Vaihinger has suggested,[505] to an objection made by Garve to the first edition, that no science, corresponding to geometry, is based on the intuition of time. For two reasons, however, the analogy between mechanics and geometry breaks down. In the first place, the conception of motion is empirical; and in the second place, it presupposes space as well as time.[506]

Kant elsewhere explicitly disavows this view that the science of motion is based on time. He had already done so in the preceding year (1786) in the _Metaphysical First Principles_. He there points out[507] that as time has only one dimension, mathematics is not applicable to the phenomena of inner sense. At most we can determine in regard to them (in addition, of course, to the two axioms already cited) only the law that all these changes are continuous. Also in Kant’s _Ueber Philosophie überhaupt_ (written some time between 1780 and 1790, and very probably in or about the year 1789) we find the following utterance:

“The general doctrine of time, unlike the pure doctrine of space
(geometry), does not yield sufficient material for a whole
science.”[508]

Why, then, should Kant in 1787 have so inconsistently departed from his own teaching? This is a question to which I can find no answer. Apparently without reason, and contrary to his more abiding judgment, he here repeats the suggestion which he had casually thrown out in the _Dissertation_[509] of 1770:

“Pure mathematics treats of space in geometry and of time in pure
mechanics.”

But in the _Dissertation_ the point is only touched upon in passing. The context permits of the interpretation that while geometry deals with space, mechanics deals with time in addition to space.

KANT’S VIEWS REGARDING THE NATURE OF ARITHMETICAL SCIENCE

In the _Dissertation_, and again in the chapter on _Schematism_ in the _Critique_ itself, still another view is suggested, namely, that the science of arithmetic is also concerned with the intuition of time. The passage just quoted from the _Dissertation_ proceeds as follows:

“Pure mathematics treats of space in geometry and of time in pure
mechanics. To these has to be added a certain concept which is in
itself intellectual, but which demands for its concrete
actualisation (_actuatio_) the auxiliary notions of time and space
(in the successive addition and in the juxtaposition of a
plurality). This is the concept of number which is dealt with in
_Arithmetic_.”[510]

This view of arithmetic is to be found in both editions of the _Critique_. Arithmetic depends upon the synthetic activity of the understanding; the conceptual element is absolutely essential.

“Our counting (as is easily seen in the case of large numbers) is a
synthesis according to concepts, because it is executed according
to a common ground of unity, as, for instance, the decade
(_Dekadik_).”[511] “The pure image ... of all objects of the senses
in general is time. But the pure _schema_ of quantity, in so far as
it is a concept of the understanding, is _number_, a representation
which combines the successive addition of one to one (homogeneous).
Thus number is nothing but the unity of the synthesis of the
manifold of a homogeneous intuition in general, whereby I generate
time itself in the apprehension of the intuition.”[512]

This is also the teaching of the _Methodology_.[513] Now it may be observed that in none of these passages is arithmetic declared to be the _science of time_, or even to be based on the intuition of time. In 1783, however, in the _Prolegomena_, Kant expresses himself in much more ambiguous terms, for his words imply that there is a parallelism between geometry and arithmetic.

“Geometry is based upon the pure intuition of space. Arithmetic
produces its concepts of number through successive addition of
units in time, and pure mechanics especially can produce its
concepts of motion only by means of the representation of
time.”[514]

The passage is by no means explicit; the “especially” (_vornehmlich_) seems to indicate a feeling on Kant’s part that the description which he is giving of arithmetic is not really satisfactory. Unfortunately this casual statement, though never repeated by Kant in any of his other writings, was developed by Schulze in his _Erläuterungen_.

“Since geometry has space and arithmetic has counting as its object
(and counting can only take place by means of time), it is evident
in what manner geometry and arithmetic, that is to say pure
mathematics, is possible.”[515]

Largely, as it would seem,[516] through Schulze, whose _Erläuterungen_ did much to spread Kant’s teaching, this view came to be the current understanding of Kant’s position. The nature of arithmetic, as thus popularly interpreted, is expounded by Schopenhauer in the following terms:

“In time every moment is conditioned by the preceding. The ground
of existence, as law of the sequence, is thus simple, because time
has only one dimension, and no manifoldness of relations can be
possible in it. Every moment is conditioned by the preceding; only
through the latter can we attain to the former; only because the
latter was, and has elapsed, does the former now exist. All
counting rests upon this nexus of the parts of time; its words
merely serve to mark the single steps of the succession. This is
true of the whole of arithmetic, which throughout teaches nothing
but the methodical abbreviations of counting. Every number
presupposes the preceding numbers as grounds of its existence; I
can only reach them through all the preceding, and only by means of
this insight into the ground of its existence do I know that, where
ten are, there are also eight, six, four.”[517]

Schulze was at once challenged to show that this was really Kant’s teaching, and the passage which he cited was Kant’s definition of the schema of number, above quoted.[518] It is therefore advisable that we should briefly discuss the many difficulties which this passage involves. What does Kant mean by asserting that in the apprehension of number we generate time? Does he merely mean that time is required for the process of counting? Counting is a process through which numerical relations are discovered; and it undoubtedly occupies time. But so do all processes of apprehension, in the study of geometry no less than of arithmetic. That this is not Kant’s meaning, and that it is not even what Schulze, notwithstanding his seemingly explicit mode of statement, intends to assert, is clearly shown by a letter written by Kant to Schulze in November 1788. Schulze, it appears, had spoken of this very matter.

“_Time, as you justly remark, has no influence upon the properties
of numbers_ (as pure determinations of quantity), such as it may
have upon the nature of those changes (of quantity) which are
possible only in connection with a specific property of inner sense
and its form (time). _The science of number, notwithstanding the
succession which every construction of quantity demands, is a pure
intellectual synthesis which we represent to ourselves in thought._
But so far as _quanta_ are to be numerically determined, they must
be given to us in such a way that we can apprehend their intuition
in successive order, and such that their _apprehension_ can be
subject to time....”[519]

No more definite statement could be desired of the fact that though in arithmetical science as in other fields of study our processes of apprehension are subject to time, the quantitative relations determined by the science are independent of time and are intellectually apprehended.

But if the above psychological interpretation of Kant’s teaching is untenable, how is his position to be defined? We must bear in mind the doctrine which Kant had already developed in his pre-Critical period, that mathematical differs from philosophical knowledge in that its concepts can have concrete individual form.[520] In the _Critique_ this difference is expressed in the statement that the mathematical sciences alone are able to _construct_ their concepts. And as they are _pure_ mathematical sciences, this construction is supposed to take place by means of the _a priori_ manifold of space and of time. Now though Kant had a fairly definite notion of what he meant by the construction of geometrical figures in space, his various utterances seem to show that in regard to the nature of arithmetical and algebraic construction he had never really attempted to arrive at any precision of view. To judge by the passage already quoted[521] from the _Dissertation_, Kant regarded space as no less necessary than time to the construction or intuition of number. ”[The intellectual concept of number] demands for its concrete actualisation the auxiliary notions of time _and space_ (in the successive addition and in the _juxtaposition of a plurality_)” A similar view appears in the _Critique_ in A 140 = B 179 and in B 15. In conformity, however, with the general requirements of his doctrine of _Schematism_, Kant defines the schema of number in exclusive reference to time; and, as we have noted, it is to this definition that Schulze appeals in support of his view of arithmetic as the science of counting and therefore of time. It at least shows that Kant perceived _some_ form of connection to exist between arithmetic and time. But in this matter Kant’s position was probably simply a corollary from his general view of the nature of mathematical science, and in particular of his view of geometry, the “exemplar”[522] of all the others. Mathematical science, as such, is based on intuition;[523] therefore arithmetic, which is one of its departments, must be so likewise. No attempt, however, is made to define the nature of the intuitions in which it has its source. Sympathetically interpreted, his statements may be taken as suggesting that arithmetic is the study of _series_ which find concrete expression in the order of sequent times. The following estimate, given by Cassirer,[524] does ample justice both to the true and to the false elements in Kant’s doctrine.

”[Even discounting Kant’s insistence upon the conceptual character
of arithmetical science, and] allowing that he derives arithmetical
concepts and propositions from the _pure intuition of time_, this
teaching, to whatever objections it may lie open, has certainly not
the merely _psychological_ meaning which the majority of its
critics have ascribed to it. If it contained only the trivial
thought, that the empirical act of counting requires time, it would
be completely refuted by the familiar objection which B. Beneke has
formulated: ‘The fact that time elapses in the process of counting
can prove nothing; for what is there over which time does not
flow?’ It is easily seen that Kant is only concerned with the
‘transcendental’ determination of the concept of time, according to
which it appears as the type of an ordered sequence. William
[Rowan] Hamilton, who adopts Kant’s doctrine, has defined algebra
as ‘science of pure time or _order in progression_.’ That the whole
content of arithmetical concepts can really be obtained from the
fundamental concept of _order_ in unbroken development, is
completely confirmed by Russell’s exposition. As against the
Kantian theory it must, of course, be emphasised, that it is not
the _concrete_ form of time intuition which constitutes the
_ground_ of the concept of number, but that on the contrary the
pure logical concepts of sequence and of order are already
implicitly contained and embodied in that concrete form.”

Much of the unsatisfactoriness of Kant’s argument is traceable to his mode of conceiving the “construction”[525] of mathematical concepts. All concepts, he seems to hold, even those of geometry and arithmetic, are abstract class concepts--the concept of triangle representing the properties common to all triangles, and the concept of seven the properties common to all groups that are seven. Mathematical concepts differ, however, from other concepts in that they are capable of _a priori_ construction, that is, of having their objects represented in pure intuition. Now this is an extremely unfortunate mode of statement. It implies that mathematical concepts have a dual mode of existence, first as abstracted, and secondly as constructed. Such a position is not tenable. The concept of seven, in its primary form, is not abstracted from a variety of particular groups of seven; it is already involved in the apprehension of each of them as being seven. Nor is it a concept that is itself constructed. It may perhaps be described as being the representation of something constructed; but that something is not itself. It represents the process or method generative of the complex for which it stands. Thus Kant’s distinction between the intuitive nature of mathematical knowledge and the merely discursive character of conceptual knowledge is at once inspired by the very important distinction between the product of construction and the product of abstraction, and yet at the same time is also obscured by the quite inadequate manner in which that latter distinction has been formulated. Kant has again adhered to the older logic even in the very act of revising its conclusions; and in so doing he has sacrificed the Critical doctrines of the _Analytic_ to the pre-Critical teaching of the _Dissertation_ and _Aesthetic_. _Mathematical concepts are of the same general type as the categories; their primary function is not to clarify intuitions, but to make them possible._ They are derivable from intuition only in so far as they have contributed to its constitution. If intuition contains factors additional to the concepts through which it is interpreted, these factors must remain outside the realm of mathematical science, until such time as conceptual analysis has proved itself capable of further extension.

I may now summarise this general discussion. Though Kant in the first edition of the _Critique_ had spoken of the mathematical sciences as based upon the intuition of space and time, he had not, despite his constant tendency to conceive space and time as parallel forms of existence, based any separate mathematical discipline upon time. His definition of number, in the chapter on _Schematism_, had recognised the essentially conceptual character of arithmetic, and had connected it with time only in a quite indirect manner. A passage in the _Prolegomena_ is the one place in all Kant’s writings in which he would seem to assert, though in brief and quite indefinite terms, that arithmetic is related to time as geometry is related to space. No such view of arithmetic is to be found in the second edition of the _Critique_. In the transcendental exposition of time, added in the second edition, only pure mechanics is mentioned. This would seem to indicate that Kant had made the above statement carelessly, without due thought, and that on further reflection he found himself unable to stand by it. The omission is the more significant in that Kant refers to arithmetic in the passages added in the second edition _Introduction_. The teaching of these passages, apart from the asserted necessity of appealing to fingers or points,[526] harmonises with the view so briefly outlined in the _Analytic_. Arithmetic is a conceptual science; though it finds in ordered sequence its intuitional material, it cannot be adequately defined as being the science of time.

CONCLUSIONS FROM THE PRECEDING CONCEPTS[527]

These _Conclusions_ do not run parallel with the corresponding _Conclusions_ in regard to space. In the first paragraph there are two differences. (_a_) Kant takes account of a view not considered under space, viz. that time is a self-existing substance. He rejects it on a ground which is difficult to reconcile with his recognition of a manifold of intuition as well as a manifold of sense, namely that it would then be something real without being a real object. In A 39 = B 57 and B 70 Kant describes space and time, so conceived, as _unendliche Undinge_. (_b_) Kant introduces into his first _Conclusion_ the argument[528] that only by conceiving time as the form of inner intuition can we justify _a priori_ synthetic judgments in regard to objects.

=Second Paragraph (Conclusion b).=--This latter statement is repeated at the opening of the second _Conclusion_. The emphasis is no longer, however, upon the term “form” but upon the term “inner”; and Kant proceeds to make assertions which by no means follow from the five arguments, and which must be counted amongst the most difficult and controversial tenets of the whole _Critique_. (_a_) Time is not a determination of outer appearances. For it belongs neither to their shape nor to their position--and prudently at this point the property of motion is smuggled out of view under cover of an etc. _Time does not determine the relation of appearances to one another, but only_ the relation of representations _in our inner state_.[529] It is the form only of the intuition of ourselves and of our inner state.[530] Obviously these are assertions which Kant cannot possibly hold to in this unqualified form. In the very next paragraph they are modified and restated. (_b_) As this inner intuition supplies no shape (_Gestalt_), we seek to make good this deficiency by means of analogies. We represent the time-sequence through a line progressing to infinity in which the manifold constitutes a series of only one dimension. From the properties of this line, with the one exception that its parts are simultaneous whereas those of time are always successive, we conclude to all the properties of time.

The wording of the passage seems to imply that such symbolisation of time through space is helpful but not indispensably necessary for its apprehension. That it is indispensably necessary is, however, the view to which Kant finally settled down.[531] But he has not yet come to clearness on this point. The passage has all the signs of having been written prior to the _Analytic_. Though Kant seems to have held consistently to the view that time has, in or by itself, only one dimension,[532] the difficulties involved drove him to recognise that this is true only of time as the order of our representations. It is not true of the objective time apprehended in and through our representations. When later Kant came to hold that consciousness of time is conditioned by consciousness of space, he apparently also adopted the view that, by reference to space, time indirectly acquires simultaneity as an additional mode. The objective spatial world is in time, but in a time which shows simultaneity as well as succession. In the _Dissertation_[533] Kant had criticised Leibniz and his followers for neglecting simultaneity, “the most important consequence of time.”

“Though time has only one dimension, yet the _ubiquity_ of time (to
employ Newton’s term), through which all things sensuously
thinkable are _at some time_, adds another dimension to the
quantity of actual things, in so far as they hang, as it were, upon
the same point of time. For if we represent time by a straight line
extended to infinity, and simultaneous things at any point of time
by lines successively erected [perpendicular to the first line],
the surface thus generated will represent the _phenomenal world_
both as to substance and as to accidents.”

Similarly in A 182 = B 226 of the _Critique_ Kant states that simultaneity is not a mode of time,[534] since none of the parts of time can be simultaneous, and yet also teaches in A 177 = B 219 that, as the order of _appearances_, time possesses in addition to succession the two modes, duration and simultaneity. The significance of this distinction between time as the order of our inner states, and time as the order of objective appearances, we shall consider immediately.

A connected question is as to whether or not Kant teaches the possibility of simultaneous apprehension. In the _Aesthetic_ and _Dialectic_ he certainly does so. Space is given as containing coexisting parts, and[535] can be intuited as such without successive synthesis of its parts. In the _Analytic_, on the other hand, the opposite would seem to be implied.[536] The apprehension of a manifold can only be obtained through the successive addition or generation of its parts.

(_c_) Lastly, Kant argues that the fact that all the relations of time can be expressed in an outer intuition is proof that the representation of time is itself intuition. But surely if, as Kant later taught, time can be apprehended at all only in and through space, that, taken alone, would rather be a reason for denying it to be itself intuition. In any case it is difficult to follow Kant in his contention that the intuition of time is similar in general character to that of space.[537]

=Third Paragraph (Conclusion c).=--Kant now reopens the question as to the relation in which time stands to outer appearances. As already noted, he has argued in the beginning of the previous paragraph that it cannot be a determination of outer appearances, but only of representations in our inner state. External appearances, however, as Kant recognises, can be known only in and through representations. To that extent they belong to inner sense, and consequently (such is Kant’s argument) are themselves subject to time. Time, as the immediate condition of our representations, is also the mediate condition of appearances. Therefore, Kant concludes, “all _appearances_, _i.e._ all _objects_ of the senses, are in time, and necessarily stand in time-relations.”

Now quite obviously this argument is invalid if the distinction between representations and their objects is a real and genuine one. For if so, it does not at all follow that because our _representations_ of objects are in time that the objects themselves are in time. In other words, the argument is valid only from the standpoint of extreme subjectivism, according to which objects are, in Kant’s own phraseology, _blosse Vorstellungen_. But the argument is employed to establish a realist conclusion, that outer objects, as objects, stand in time-relations to one another. In contradiction of the previous paragraph he is now maintaining that time is a determination of outer appearances, and that it reveals itself in the motion of bodies as well as in the flux of our inner states.

The distinction between representations and their objects also makes it possible for Kant both to assert and to deny that simultaneity is a mode of time. “No two years can be coexistent. Time has only one dimension. But existence (_das Dasein_), measured through time, has two dimensions, succession and simultaneity.” There are, for Kant, two orders of time, subjective and objective. Recognition of the latter (emphasised and developed in the _Analytic_)[538] is, however, irreconcilable with his contention that time is merely the form of inner sense.

We have here one of the many objections to which Kant’s doctrine of time lies open. It is the most vulnerable tenet in his whole system. A mere list of the points which Kant leaves unsettled suffices to show how greatly he was troubled in his own mind by the problems to which it gives rise. (1) The nature of the _a priori_ knowledge which time yields. Kant ascribes to this source sometimes only the two axioms in regard to time, sometimes pure mechanics, and sometimes also arithmetic. (2) Whether time only allows of, or whether it demands, representation through space. Sometimes Kant makes the one assertion, sometimes the other. (3) Whether it is possible to apprehend the coexistent without successive synthesis of its parts. This possibility is asserted in the _Aesthetic_ and _Dialectic_, denied in the _Analytic_. (4) Whether simultaneity is a mode of time. (5) Whether, and in what manner, appearances of outer sense are in time. Kant’s answer to 4 and to 5 varies according as he identifies or distinguishes representations and empirical objects.

The manifold difficulties to which a theory of time thus lies open are probably the reason why Kant, in the _Critique_, reverses the order in which he had treated time and space in the _Dissertation_.[539] But the placing of space before time is none the less unfortunate. It greatly tends to conceal from the reader the central position which Kant has assigned to time in the _Analytic_. Consciousness of time is the fundamental fact, taken as bare fact, by reference to which Kant gains his transcendental proof of the categories and principles of understanding.[540] In the _Analytic_ space, by comparison, falls very much into the background. A further reason for the reversal may have been Kant’s Newtonian view of geometry as the mathematical science _par excellence_.[541] In view of his formulation of the Critical problem as that of accounting for synthetic _a priori_ judgments, he would then naturally be led to throw more emphasis on space.

To sum up our main conclusions. Kant’s view of time as a form merely of inner sense, and as having only one dimension, connects with his subjectivism. His view of it as inhering in objects, and as having duration and simultaneity as two of its modes, is bound up with his phenomenalism. Further discussion of these difficulties must therefore be deferred until we are in a position to raise the more fundamental problem as to the nature of the distinction between a representation and its object.[542] Motion is not an inner state. Yet it involves time as directly as does the flow of our feelings and ideas. Kant’s assertion that “time can no more be intuited externally than space can be intuited as something in us,”[543] if taken quite literally, would involve both the subjectivist assertion that motion of bodies is non-existent, and also the phenomenalist contention that an extended object is altogether distinct from a representation.

The _fourth_ and _fifth_ paragraphs call for no detailed analysis.[544] Time is empirically real, transcendentally ideal--these terms having exactly the same meaning and scope as in reference to space.[545] The fourth sentence in the fifth paragraph is curiously inaccurate. As it stands, it would imply that time is given through the senses. In the concluding sentences Kant briefly summarises and applies the points raised in these fourth and fifth paragraphs.

ELUCIDATION

=First and Second Paragraphs.=--Kant here replies to a criticism which, as he tells us in his letter of 1772 to Herz, was first made by Pastor Schulze and by Lambert.[546] In that letter the objection and Kant’s reply are stated as follows.

“In accordance with the testimony of inner sense, changes are
something real. But they are only possible on the assumption of
time. Time is, therefore, something real which belongs to the
determinations of things in themselves. Why, said I to myself, do
we not argue in a parallel manner: ‘Bodies are real, in accordance
with the outer senses. But bodies are possible only under the
condition of space. Space is, therefore, something objective and
real which inheres in the things themselves.’ The cause [of this
differential treatment of space and of time] is the observation
that in respect to outer things we cannot infer from the reality of
representations the reality of their objects, whereas in inner
sense the thought or the existing of the thought and of myself are
one and the same. Herein lies the key to the difficulty.
Undoubtedly I must think my own state under the form of time, and
the form of the inner sensibility consequently gives me the
appearance of changes. Now I do not deny that changes are something
real any more than I deny that bodies are something real, but I
thereby mean only that something real corresponds to the
appearance. I may not even say the inner appearance undergoes
change (_verändere sich_), for how could I observe this change
unless it appeared to my inner sense? _To the objection that this
leads to the conclusion that all things in the world objectively
and in themselves are unchangeable, I would reply that they are
neither changeable nor unchangeable._ As Baumgarten states in § 18
of his _Metaphysica_, the absolutely impossible is hypothetically
neither possible nor impossible, since it cannot be mentally
entertained under any condition whatsoever; so in similar manner
_the things of the world are objectively or in themselves neither
in one and the same state nor in different states at different
times, for thus understood [viz. as things in themselves] they are
not represented in time at all_.”[547]

Thus Kant’s contention, both in this letter and in the passage before us, is that even our inner states would not reveal change if they could be apprehended by us or by some other being apart from the subjective form of our inner sense. We may not say that our inner states undergo change, or that they succeed one another, but only that to us they necessarily appear as so doing.[548] Time is no more than subjectively real.[549] As Körner writes to Schiller: “Without time man would indeed _exist_ but not _appear_. Not his reality but only his appearance is dependent upon the condition of time.” “Man _is_ not, but only _appears_, when he undergoes change.”[550] The objects of inner sense stand in exactly the same position as those of outer sense. Both are appearances, and neither can be identified with the absolutely real. As Kant argues later in the _Critique_,[551] inner processes are not known with any greater certainty or immediacy than are outer objects; the reality of time as subjective proves its unreality in relation to things in themselves. The statement that the constitution of things in themselves is “problematic” is an exceptional mode of expression for Kant. Usually--as indeed throughout the whole context of this passage[552]--he asserts that though things in themselves are unknowable, we can with absolute certainty maintain that they are neither in space nor in time. Upon this point we have already dwelt in discussing Trendelenburg’s controversy with Fischer.[553]

=Third Paragraph.=--The third and fourth paragraphs of this section ought to have had a separate heading. They summarise the total argument of the _Aesthetic_ in regard to space as well as time, distinguish its tenets from those of Newton and of Leibniz, and draw a general conclusion. The summary follows the strict synthetic method. The opening sentences illustrate Kant’s failure to distinguish between the problems of pure and of applied mathematics, and also show how completely he tends to conceive mathematics as typified by geometry. The criticism of alternative views traverses the ground of the famous controversy between Leibniz and Clarke. Their _Streitschriften_ were, as we have good circumstantial grounds for believing,[554] a chief influence in the development of Kant’s own views. Kant, who originally held the Leibnizian position, was by 1768[555] more or less converted to the Newtonian teaching, and in the _Dissertation_ of 1770 developed his subjectivist standpoint with the conscious intention of retaining the advantages while remedying the defects of both alternatives.[556] For convenience we may limit the discussion to space. (_a_) The view propounded by Newton, and defended by Clarke, is that space has an existence in and by itself, independent alike of the mind which apprehends it and of the objects with which it is filled. (_b_) The view held by Leibniz is that space is an empirical concept abstracted from our confused sense-experience of the relations of real things.[557]

The criticism of (_a_) is twofold. First, it involves belief in an eternal and infinite _Unding_. Secondly, it leads to metaphysical difficulties, especially in regard to the existence of God. If space is absolutely real, how is it to be reconciled with the omnipresence of God? Newton’s view of space as the =sensorium Dei= can hardly be regarded as satisfactory.

The objection to (_b_) is that it cannot account for the apodictic certainty of geometry, nor guarantee its application to experience. The concept of space, when regarded as of sensuous origin, is something that may distort (and according to the Leibnizian teaching does actually distort) what it professes to represent, and is something from which restrictions that hold in the natural world have been omitted.[558] As empirical, it cannot serve as basis for the universal and necessary judgments of mathematical science.[559]

The first view has, however, the advantage of keeping the sphere of appearances open for mathematical science. As space is infinite and all-comprehensive, its laws hold universally. The second view has the advantage of not subjecting reality to space conditions. These advantages are retained, while the objections are removed, by the teaching of the _Aesthetic_.

Kant further criticises the former view in A 46 ff. = B 64 ff. There is no possibility of accounting for the _a priori_ synthetic judgments of geometry save by assuming that space is the pure form of outer intuition. For though the Newtonian view will justify the assertion that the laws of space hold universally, it cannot explain how we come to know them _a priori_. And assuming, as Kant constantly does, that space cannot be both an _a priori_ form of intuition and also independently real, he concludes that it is the former only.

In B 71 Kant also restates the metaphysical difficulties to which the Newtonian view lies open. In natural theology we deal with an existence which can never be the object of sensuous intuition, and which has to be freed from all conditions of space and time. This is impossible if space is so absolutely real that it would remain though all created things were annihilated.

=Fourth Paragraph.=--Space and time are the only two forms of sensibility; all other concepts belonging to the senses, such as motion and change, are empirical.[560] As Kant has himself stated, no reason can be given why space and time are the sole forms of our possible intuition:

“Other forms of intuition than space and time, ... even if they
were possible, we cannot render in any way conceivable and
comprehensible to ourselves, and even assuming that we could do so,
they still would not belong to experience, the only kind of
knowledge in which objects are given to us.”[561]

The further statement,[562] frequently repeated in the _Critique_, that time itself does not change, but only what is in time,[563] indicates the extent to which Kant has been influenced by the Newtonian receptacle view. As Bergson very justly points out, time, thus viewed as a homogeneous medium, is really being conceived on the analogy of space. “It is merely the phantom of space obsessing the reflective consciousness.”[564]

GENERAL OBSERVATIONS ON THE TRANSCENDENTAL AESTHETIC

=I. First Paragraph.=--“To avoid all misapprehension” Kant proceeds to state “as clearly as possible” his view of sensuous knowledge. With this end in view he sets himself to enforce two main points: (_a_) that as space and time are only forms of sensibility, everything apprehended is only appearance; (_b_) that this is not a mere hypothesis but is completely certain. Kant expounds (_a_) indirectly through criticism of the opposing views of Leibniz and of Locke. But before doing so he makes in the next paragraph a twofold statement of his own conclusions.

=Second Paragraph.=--This paragraph states (_a_) that through intuition we can represent only appearances, not things in themselves, and (_b_) that the appearances thus known exist only in us. Both assertions have implications, the discussion of which must be deferred to the _Analytic_. The mention of the “relations of things by themselves” may, as Vaihinger suggests,[565] be a survival from the time when (as in the _Dissertation_[566]) Kant sought to reduce spatial to dynamical relations. The assertion that things in themselves are completely unknown to us goes beyond what the _Aesthetic_ can establish and what Kant here requires to prove. His present thesis is only that no knowledge of things in themselves can be acquired either through the forms of space and time or through sensation; space and time are determined solely by our pure sensibility, and sensations by our empirical sensibility. Failure to recognise this is, in Kant’s view, one of the chief defects of the Leibnizian system.

=Third and Fourth Paragraphs. Criticism of the Leibniz-Wolff Interpretation of Sensibility and of Appearance.=--Leibniz vitiates both conceptions. Sensibility does not differ from thought in clearness but in content. It is a difference of kind.[567] They originate in different sources, and neither can by any transformation be reduced to the other.

“Even if an appearance could become completely transparent to us,
such knowledge would remain _toto coelo_ different from knowledge
of the object in itself.”[568] “Through observation and analysis of
appearances we penetrate to the secrets of nature, and no one can
say how far this may in time extend.... [But however far we
advance, we shall never be able by means of] so ill-adapted an
instrument of investigation [as our sensibility] to find anything
except still other appearances, the non-sensuous cause of which we
yet long to discover.”[569]

We should still know only in terms of the two inalienable forms of our sensibility.[570] The dualism of thought and sense can never be transcended by the human mind. By no extension of its sphere or perfecting of its insight can sensuous knowledge be transformed into a conceptual apprehension of purely intelligible entities.

Leibniz’s conception of appearances as things in themselves confusedly apprehended is equally false, and for the same reasons.[571] Appearance and reality are related as distinct existences, each of which has its own intrinsic character and content. Through the former there can be no hope of penetrating to the latter. Appearance is subjective in matter as well as in form. For Leibniz our knowledge of appearances is a confused knowledge of things in themselves. Properly viewed, it is the apprehension, whether distinct or confused, of objects which are never things in themselves. Sense-knowledge, such as we obtain in the science of geometry, has often the highest degree of clearness. Conceptual apprehension is all too frequently characterised by obscurity and indistinctness.

This criticism of Leibniz, as expounded in these two paragraphs, is thoroughly misleading if taken as an adequate statement of Kant’s view of the relations between sense and understanding, appearance and reality. These paragraphs are really a restatement of a passage in the _Dissertation_.

“It will thus be seen that we express the nature of the sensuous
very inappropriately when we assert that it is the _more
confusedly_ known, and the nature of the intellectual when we
describe it as the _distinctly_ known. For these are merely logical
distinctions, and obviously have nothing to do with the given facts
which underlie all logical comparison. The sensuous may be
absolutely distinct, and the intellectual extremely confused. That
is shown on the one hand in _geometry_, the prototype of sensuous
knowledge, and on the other in _metaphysics_, the instrument of all
intellectual enquiry. Every one knows how zealously metaphysics has
striven to dispel the mists of confusion which cloud the minds of
men at large and yet has not always attained the happy results of
the former science. Nevertheless each of these kinds of knowledge
preserves the mark of the stock from which it has sprung. The
former, however distinct, is on account of its origin entitled
sensuous, while the latter, however confused, remains
intellectual--as _e.g._ the _moral_ concepts, which are known not
by way of experience, but through the pure intellect itself. I
fear, however, that Wolff by this distinction between the sensuous
and the intellectual, which for him is merely logical, has checked,
perhaps wholly (to the great detriment of philosophy), that noblest
enterprise of antiquity, the investigation of _the nature of
phenomena and noumena_, turning men’s minds from such enquiries to
what are very frequently only logical subleties.”[572]

The paragraphs before us give expression only to what is common to the _Dissertation_ and to the _Critique_, and do so entirely from the standpoint of the _Dissertation_. Thus the illustration of the conception of “right” implies that things in themselves can be known through the understanding. The conception, as Kant says, represents “a moral property which belongs to actions in and by themselves.” Similarly, in distinguishing the sensuous from “the intellectual,” he says that through the former we do not apprehend things in themselves, thus implying that things in themselves can be known through the pure intellect. The view developed in the _Analytic_, alike of sensibility and of appearance, is radically different. Sensibility and understanding _may_ have a common source; and both are indispensably necessary for the apprehension of appearance. Neither can function save in co-operation with the other. Appearance does not differ from reality solely through its sensuous content and form, but also in the intellectual order or dispensation to which it is subject. But in the very act of thus deepening the gulf between appearance and reality by counting even understanding as contributing to the knowledge only of the former, he was brought back to a position that has kinship with the Leibnizian view of their interrelation. Since understanding is just as essential as sensibility to the apprehension of appearances, and since understanding differs from sensibility in the universality of its range, it enables us to view appearances in their relation to ultimate reality, and so to apprehend them as being, however subjective or phenomenal, ways in which the thing in itself presents itself to us. Such a view is, however, on Kant’s principles, quite consistent with the further contention, that appearance does not differ from reality in a merely logical manner. Factors that are peculiar to the realm of appearance have intervened to transform the real; and in consequence even completed knowledge of the phenomenal--if such can be conceived as possible--would not be equivalent to knowledge of things in themselves.

=Fifth Paragraph. Criticism of Locke’s View of Appearance.=--This paragraph discusses Locke’s doctrine[573] that the secondary qualities are subjective, and that in the primary qualities we possess true knowledge of things in themselves. The distinction is drawn upon empirical grounds, namely, that while certain qualities are uniform for more than one sense, and belong to objects under all conditions, others are peculiar to the different senses, and arise only through the accidental relation of objects to the special senses.[574] This distinction is, Kant says, entirely justified from the physical standpoint.[575] A rainbow is an appearance of which the raindrops constitute the true empirical reality. But Locke and his followers interpret this distinction wrongly. They ignore the more fundamental transcendental (_i.e._ metaphysical) distinction between empirical reality and the thing in itself. From the transcendental standpoint the raindrops are themselves merely appearance. Even their round shape, and the very space in which they fall; are only modifications of our sensuous intuition. The ‘transcendental object’[576] remains unknown to us.

When Kant thus declares that the distinction between primary and secondary qualities is justified (_richtig_) from the physical standpoint, he is again[577] speaking from a phenomenalist point of view. And it may be noted that in developing his transcendental distinction he does not describe the raindrops as mere representations. His phrase is much more indefinite. They are “modifications or fundamental forms (_Grundlagen_) of our sensuous intuition.”

Kant does not here criticise the view of sensibility which underlies Locke’s view of appearance. But he does so in A 271 = B 327, completing the parallel and contrast between Leibniz and Locke.

“Leibniz _intellectualised_ appearances, just as Locke, according
to his system of noogony (if I may be allowed these expressions),
_sensualised_ all concepts of the understanding, _i.e._ interpreted
them as simply empirical or abstracted concepts of reflection.
Instead of interpreting understanding and sensibility as two quite
different sources of representations, which yet can supply
objectively valid judgments of things only in _conjunction_ with
each other, each of these great men holds only to one of the two,
viewing it as in immediate relation to things in themselves. The
other faculty is regarded as serving only to confuse or to order
the representations which this selected faculty yields.”[578]