ANCES OR " PHENOMENA," BUT OF MATERIAL REALITIES.

К оглавлению 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33
34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67
68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84
85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101
102 103 104 105 106 107 108 109 110  112 113 114 115  117 118
119 120 121 122 123 124 125  127 128 129 130 131 132 133 134 135
  138 139 140 141 142 143 144 145 146 147 148

The

aim of the arguments just examined was to establish (i) that

space is a priori, (2) that it is a pure perception : from which two

characteristics it was to follow that space is a property not of

things in themselves but only of phenomena or mental appear

ances. In drawing this latter conclusion 2 Kant gives another

argument in support of the second characteristic, 3 an argument

based on the supposed synthetic a priori (and at the same time

intuitively evident) character of geometrical judgments. Since

we have already shown this latter position to be untenable (63)

we need not examine the argument in detail. But some points

1 C/. Critique, pp. 56-7, quoted vol. i., 52, pp. 186-7.

2 Ibid., pp. 20-4. 3 Ibid. (2nd edit.), pp. 728-9; Prolegomena, 6-n.

KANTS THEORY OF SENSE PERCEPTION, ETC. 197

in it are worthy of notice ; and his attempt to infer from the

supposed a priori and perceptive character of our apprehension of

space his final conclusion that space is a property of phenomena

only, and not of things in themselves, has also to be examined.

(1) Arguing from the character of geometrical judgments he

admits that all such judgments are intuitive or perceptive. 1 This

obliges him to apply the term a priori to perception as well as to

judgment. Applied to perception it can have only a temporal

sense and must mean " prior to all experience " ; and, as Prichard

remarks, 2 "since the object of perception is essentially individual, 3

the use of the term gives rise to the impossible task of explain

ing how a perception can take place prior to the actual experience

of an individual in perception ".

(2) Kant contends that such a perception (of empty space)

does take place, but that it can take place only if space, or the

perception of space (which he identifies with space 4 ), be a char

acteristic of our perceiving nature ; 5 and since such perception

does take place it must be such a characteristic.

(3) The question, How is it possible to perceive anything (in

this case, empty space) a priori? raising as it does the insuper

able difficulty of perceiving an object before the object is given,

forces Kant, therefore, to hold that what we apprehend in such

a perception can be only our own nature as percipient beings, or,

in other words, the mode in which we must necessarily perceive

objects when they are given (in empirical perception) : the reason

apparently being that nothing else but our own nature as per

cipient beings is present to us in such an a priori perception. " I

can only know what is contained in the object in itself, if it is

present and given to me" 6 as it is in empirical perception, in

which Kant allows the possibility of our knowing the given object

as it is in itself, 7 though only with a contingent, a posteriori

knowledge. In a priori perception, at all events, we can appre

hend only our own perceptive nature, or the mode in which subse-

1 Prol., 7. 2 Op. cit., p. 60 n.

Cf. Critique, pp. 572-3. 4 C/. PRICHARD, p. 51 n.

5 Critique, p. 729; Prol., 9 : " It is therefore possible only in one way for my

perception to precede the actuality of the object and to take place as a priori know

ledge, viz. if it contains nothing but the form of sensibility, which precedes in me,

the subject, all actual impressions through which I am affected by objects," apud

PRICHARD, p. 55.

6 Prol., 9.

~ This important admission (ibid.) has been referred to already supra, p. 185, n.

1 98 THEOR I OF KNO W I. EDGE

quently the sensuous content given in empirical perception

must necessarily be apprehended.

(4) From this the final conclusion is plausibly inferred, viz. that

the sensuous datum or material which is given in empirical intui

tion, and which is necessarily apprehended therein as spatial (owing

to the mode of our perceiving nature being spatial a priori] must

be itself something exclusively mental, must be, and be appre

hended as, a mental appearance or phenomenon, and cannot pos

sibly be anything extramental or any thing-in-itself : for if in

perceiving empty space a priori we are apprehending a law of our

nature as perceptive, then our empirical perceptions, or objects

empirically perceived, are spatial only because by being mental

appearances they come under the a priori mental law ; while it

must on the other hand remain impossible to say whether objects

apart from perception, or things in themselves, are or are not

spatial.

Plausible, however, as the conclusion is, nevertheless it is (i)

neither the conclusion warranted by his supposition that we have

an a priori perception of empty space whereby we can discover

the rules of spatial relation (geometrical truths) which must

apply to all spatial objects subsequently (and empirically) per

ceived ; nor (2) is the conclusion even compatible with the sup

position on which it is based.

For firstly, what is involved in the supposition that we have

such an apprehension of empty space as will yield the geometri

cal laws to which all empirically perceived objects must conform ?

It does not involve what Kant says it does, viz. that space is a

form of sensibility, or a mode or way in which objects must ap

pear. It simply involves that space is the form of all perceivable

objects, or that all perceivable objects are spatial. 1 For, provided

that perceivable objects are spatial,

" they must be subject to the laws of space, and if, therefore, \ve can dis

cover these laws by a study of empty space, the only condition to be satisfied,

if the objects of subsequent perception are to conform to the laws which we

discover, is that all objects should be spatial. Nothing is implied which

enables us to decide whether the objects are objects as they are in themselves

or objects as perceived ; for in cither case the required result follows. If in

empirical perception we apprehend objects only as they appear to us, and if

1 That space is a form of objects (whether we call these phenomena or not) is

quite a different assertion from this other, with which Kant confounds it : that space

is a form of sensibility, or of our perception of objects.

KANTS THEORY OF SENSE PERCEPTION, ETC. 199

space is the form of them as they appear to us, it will no doubt be true that

the laws of spatial relation which we discover must apply to things as they

appear to us. But on the other hand, if in empirical perception we appre

hend things as they are, and if space is their form, i.e. if things are spatial,

it will be equally true that the laws discovered by geometry must apply to

things as they are." 1

Secondly, the conclusion that space is a characteristic of

phenomena is really incompatible with the initial supposition that

the truths of geometry imply an a priori spatial perception which

turns out to be a perception of the mind s perceiving nature. For,

strange though it may seem, Kant s account of this latter a priori

perception implies that space is a characteristic of things as they

are in themselves ! In this way : When explaining how we can

perceive the characteristics of an object before the object is given,

he allows that if the thing or object were given, or were present

to us (as in empirical perception), we could perceive the char

acteristics of it as it really is. 2 But if this is so, and if the

objects given in empirical perception are given as spatial, as Kant

allows that they are, then it follows that space is their real form

and that the truths of geometry relate to them as they really are.

But if so, Kant s presupposition would involve this, that in per

ceiving empty space a priori we should be perceiving a real

characteristic of things in space before actually perceiving the

things ; "and no doubt, Kant thinks this impossible". 2 But, as

Prichard justly maintains, no greater difficulty is really involved

in it than in Kant s actual presupposition that we perceive how

objects will appear, before they actually do appear : " It is really

just as difficult to hold that we can perceive a characteristic of

things as they appear to us before they appear, as to hold that we

can perceive a characteristic of them as they are in themselves

before we perceive them ". 4

The fact is, of course, that the necessary character of geo

metrical judgments does not presuppose a pure a priori perception

of empty space. But even if it did, the paradox which such a

perception presents to Kant that of perceiving the characteristics

an object must have, before the object itself is given is really a

paradox only because it is supposed that we can perceive the

characteristics of the object when it is given, i.e. in empirical per

ception ; and since we can, and since the empirically perceived

1 PRICHARD, p. 58 (italics ours). 2 Cf. supra, pp. 185, 197.

3 PRICHARD, p. 59. *Ibid.

200 THEOR Y OP AW0 WLEDGE

object is spatial, it follows that space must be a real characteristic

of such an object. Hence Kant s final conclusion is incompatible

with a portion of his initial supposition.

We referred above to the plausible character of Kant s con

clusion that space can be a characteristic only of mental pheno

mena. The conclusion is equally plausible if we connect it

directly with the absolutely necessary character of geometrical

judgments, without postulating an a priori perception of empty

space. For just as Kant argues from the necessity and uni

versality of what he calls the principles underlying physics to

the existence of a priori conceptions, and from the similar char

acteristics of mathematical judgments to the existence of a priori

perceptions, so to he infers, in regard to both classes of judgments

alike, that they cannot possibly be applicable to things in them

selves, to reality, but only to mental phenomena. The argument

for the phenomenal character of space would then be as follows :

Space is obviously that to which geometrical judgments relate,

and of which they formulate the necessary and universal laws.

But since the necessity and universality of such judgments cannot

be grounded on what is given a posteriori from without, in repeated

empirical perceptions of bodies, the validity of such judgments

can in nowise be defended on the assumption that space, of

which they formulate the laws, is a thing in itself, for how could

a necessity of thought (which such judgments express) be bind

ing on what is ex hypotJiesi independent of the nature of the

mind? If, however, that to which such judgments refer, viz,

space, be merely a mental appearance, or apprehension, or per

ception, then it is at once intelligible how a necessity of thought

could and should apply to that which is itself mental through

and through. 1

One fatal flaw in the argument as just stated is this : it as

sumes that contingent, empirical, a posteriori judgments can and do

reveal real characteristics of the things given in empirical per

ception, and that the reason why necessary, " a priori" judgments

cannot reveal real characteristics of the latter, but only character

istics of something mental, is precisely because the connexions

they reveal are necessary and universal. But as we saw already

(55), no such distinction can be drawn between necessary and

contingent judgments. To question the reality of a connexion

which we see to be necessary and which we think to be real, and

1 Cf. vol. i., 55, 94 ; infra, i.^o.

KANTS THEORY OF SENSE PERCEPTION, ETC. 201

to do so simply on the ground that it is necessary, is <( to question

the validity of thinking altogether, and to do this is implicitly to

question the validity of our thought about the nature of our own

mind, as well as the validity of thought about things independent

of the mind "- 1 What right, after all, have we to assume that we

think or judge validly about our perceptions of things any more

than about things themselves ?

Furthermore, the assumption that space is something mental

and not real, not a characteristic of things as they are but only

of our mental representations of things, in no way helps to

explain the necessary and universal validity of geometrical judg

ments. 2 Kant thinks that it does because he confounds the

necessity of apprehended spatial law, or relation, or connexion,

with the universal validity of the judgment whereby we appre

hend such law as necessary.

" No doubt [writes Prichard ], if it be a law OF OUR PERCEIVING NATURE

that, whenever we perceive an object as a three-sided figure, the object AS

PERCEIVED contains three angles, it follows that any object AS PERCEIVED

[i.e. perceived as a three-sided figure] will conform to this law ; just as if it be

a law OF THINGS AS THEY ARE IN THEMSELVES that three-sided figures con

tain three angles, all three-sided figures will IN THEMSELVES contain three

angles. But what has to be explained is the universal applicability, not of a

law, but of a judgment about a law. For Kant s real problem is to explain

why our judgment that a three-sided figure must contain three angles must

apply to all three-sided figures. Of course if it be granted that in the judg

ment we apprehend the true law, the problem may be regarded as solved.

But how are we to know that what we judge is the true law ? The answer is

in no way facilitated by the supposition that the judgment relates to our

perceiving nature. IT CAN JUST AS WELL BE URGED THAT WHAT WE THINK

TO BE A NECESSITY OF OUR PERCEIVING NATURE IS NOT A NECESSITY OF

IT AS THAT WHAT WE THINK TO BE A NECESSITY OF THINGS AS THEY

ARE IN THEMSELVES IS NOT A NECESSITY OF THEM. 4 The best, Or rather

the only possible, answer is simply that that of which we apprehend the

necessity must be true, or, in other words, that we must accept the validity

ot thought. . . . 5 No vindication of a judgment in which we are conscious

1 PRICHARD, p. 62 (italics ours). 2 C/. vol. i., 55.

3 Op. cit., pp. 63, 65-6 (capitals ours).

4 Cf. vol. i., 59, where this objection is urged against the whole reasoning of

the Critique.

5 In other words, that which the intellect, reflecting on the data of human

experience, is necessitated to think as involved in this experience, is real : what is

given to the mind for its interpretation is real : and what is seen by the mind to be

necessarily involved in the given is likewise real. This is the thesis on which scho

lastics have at all times emphatically insisted : The proper object of intellect is

reality: Objectum intellectus est Ens (cf. Science of Logic, ii., 215, p. 58). This

202 THEORY OF KNOWLEDGE

of a necessity could do more than take the problem a stage further back by

basing it upon some other consciousness of a necessity, and since this latter

judgment could be questioned for precisely the same reason, we should only

be embarking upon an infinite process."

When, therefore, Kant thinks that he has solved " the original

problem of the conformity of things to our minds " by the con

tention that the " things " about which we judge are not " things

as they are in themselves" but "perceptions," " it can be forced

upon him again, even after he thinks he has solved it, in the new

form of that of the conformity within the mind of perceiving and

thinking". 1 Of course Kant "solves" the problem, stated in

this latter form, by the contention that just as what we perceive

is not the thing in itself but a mental impression produced by

the latter and made conformable to the mind s perceiving nature

by the forms of sense perception, so what we think or conceive or

judge is not the perception but the perception transfigured once

more and made conformable with the mind s thinking or judging

nature by the categories of the understanding : a solution which

really empties the question of the validity of knowledge of all

intelligible meaning by issuing in the " logical idealism " which

identifies thought with its object and denies all " extra-logical "

reality. 2