Louise Schriek 12/01/2015

How does Kant refute Berkeley?

Kant’s two­fold refutation of Berkeleyan Idealism through the Transcendental Aesthetic and the Refutation of Idealism,

as an overture to what the ramifications of the latter may be for Kant’s

transcendental Philosophy in the face of skepticism.

This essay will firstly aim to interpret what Kant means by his claim found in the

Refutation of Idealism, that he has undermined the basis for Berkeley’s Idealism in the

Transcendental Aesthetic (Kant 1887, B275). It will be seen that a refutation of what Kant sees

to be Berkeley’s ‘material’ idealism appears in the transcendental aesthetic in two ways.

The first is holistic, through Kant defending his own philosophical system of

Transcendental Idealism, and arguing that if one were to accept the Idealism of Berkeley , what

Berkeley contends to be reality, that is what is perceived, becomes “mere illusion” (B71). This

will be acknowledged but not be dwelt on, for it comprises Kant’s philosophy as a whole, which

obviously is too much argumentation for this essay to get into. But it is more difficult to find a specific argument directly aimed at Berkeley’s thesis that

we can know that nothing mind­independent exists. This is what the second half of the first part

of this essay will aim to do, by showing that Kant’s system does leave place for the possibility of

outer (that is mind­independent) objects. This will be shown through the order of Kant’s theory

of how our conscious experience of perception comes to be, in a manner which respects, or

complies with, Berkeley’s attack on the ‘Doctrine of Abstract Ideas’, and thus seems to refute

Kant’s earlier interpretation of what Berkeley defended, which is that the existence of external

objects is impossible.

The Second part of this essay will briefly review Berkeley’s refutation of skepticism, and

use the latter as an illustration of his point of view. It will appear that, given his argument and

what would be a Kantian reading of it (which leaves out God and the role she fills), one can only

take from it that it is unnecessary and irrational to posit the existence of external objects to

explain our experience, and not as was given in the first part of the essay, that the existence of

external objects is impossible, but merely that it is philosophically unnecessary and irrational.

The third part of the essay will consequently complete Kant’s refutation of Berkeley’s

Idealism, in showing that it is not only possible to posit the existence of external objects, but that

the latter is necessary to explain our experience of the world.This will be shown through Kant’s

Refutation of Idealism, which was added to the second edition of the Critique in order for Kant to

strongly differentiate his Idealism from that of Berkeley and Descartes.

This essay does not leave enough to space to approach Kant’s refutation from a critical eye, but

will instead conclude in briefly seeing how the manner in which he refutes Berkeley affects his

own philosophy, and the space it does, or should leave, for skepticism.

This first part will thus consider Kant’s refutation of Berkeley through the Transcendental

Aesthetic.

In the Refutation of Idealism, Kant claims that the ground for what he calls Berkeley’s “Dogmatic Idealism”, “has been undercut by us in Transcendental Aesthetic” (Kant 1787, B275).

This statement is slightly enigmatic though, for as Wayne Waxman notes, Kant does not specify

how or why in the Aesthetic the grounds of this ‘dogmatic idealism’ are refuted (Waxman 2014,

p201). As Waxman puts it, the Transcendental Aesthetic:

“... contains no argument expressly dedicated to establishing,or even so much as an

explicit endorsement of the realist thesis, that the esse of sensible things is NOT percipi. Quite

the contrary, one finds iterated affirmations of the view that space and time, together with

everything in them, are, and can be, nothing other than representations in the mind..” (Waxman

2014, p201).

But already in the wording used one can see kant differentiating himself from Berkeley,

which starts to reveal the shortcomings of Waxman’s interpretation. For by the very use of the

term ’representation’, Kant’s is clearly speaking of appearances, and not of reality in itself. For

Berkeley reality is that which is directly perceived by the mind, it is not a representation of

something that would be caused by a non mind­like substance, reality is idea. For Kant our

perceptions are representations of reality that exists independently of being perceived, a reality

which affects us and causes these representations, but that is not directly perceived. There is

thus some kind of underlying substance causing, and the object of, our representations.

Kant goes one step further in somewhat negatively defining the ‘thing in itself’, by saying that it

cannot have the character of a material object, for “the transcendental idealist countenances

this matter (corporeal substance) and even its inner possibility merely as an appearance that,

separated from our sensibility, is nothing” (Kant 1787, A370).

In the Prolegomena to any future Metaphysics, Kant re­labelled his Idealism as ‘Critical’

but also ‘Formal’ Idealism, and contrasted this with what he called Descartes and Berkeley’s

types of ‘Material’ Idealism (Kant 1783).

This illustrates the way that Kant differentiates himself from Berkeley: For him, it is the formal

aspects of appearances which are ideal, whereas for Berkeley it is the material aspects, which

include the sensations and their potential underlying causes, which are ideal too.

Berkeley, in his argument against abstraction, strongly undermines the possibility of a ‘thing in

itself’, unperceived by the mind. For him, the idea of a mind­independent reality depends on the

doctrine of abstract ideas:

“For can there be a nicer strain of abstraction than to distinguish the existence of

sensible objects from their being perceived, so as to conceive them existing unperceived? For

my part I might as easily divide a thing from itself.” (Berkeley 1710, I, 5)

And such abstract ideas he argues to be logically untenable:

“... But my conceiving or imagining power does not extend beyond the possibility of real

existence or perception. Hence, as it is impossible for me to see or feel anything without an

actual sensation of that thing, so it is impossible for me to conceive in my thoughts any sensible

thing or object distinct from the sensation or perception of it” (Berkeley 1710, I, 5).

This last passage quite directly undermines Kant, whom could hereby be accused of

claiming to be able to in the abstract say that there exists a thing in itself, which he cannot think

because it does not conform to the categories of the understanding, or to space and time,

whereas following Berkeley, one must have experienced something in the mind to be able to

conceive of it.Thus Berkeley’s point here seems to undermine Kant’s possibility for thinking the

mere existence of the thing in itself, whilst knowing nothing about it, because this is a level of

abstraction which renders it absurd and void. Indeed it seems impossible to conceptualise that

existence of a thing,which itself we do not and cannot know, this existence would be empty, this

thing would be void of any properties, and so its existence unthinkable.

However, it will now be observed how Kant allows for the possibility of external objects

through the system he exposes in the Transcendental Aesthetic, without falling under the

Criticism that Berkeley made of the Doctrine of Abstract Ideas.

A clear and simple exposition of how Kant’s idealism allows for the possibility of

external objects I found very difficult to come by in my own research on the topic, and Kant does

not himself clearly express it in this way. This is why I am coming to quote the lecture material of

a certain Dr Jason Potter from the University of University Colorado Boulder, despite the fact

that it does not fall under the criteria of published work, as it was the best formulation I came

across uniquely in his work:

“Insofar as forms of intuition (pure time and space) are essential for the perception

(empirical consciousness, presence to the mind) of the manifold of sensation, I have only to

posit the loss of these forms to render perception impossible, without thereby being obliged to

suppose that the manifold of sensation itself ceases to exist. In other words, the elimination of

the form of appearance suffices to eliminate appearances, but not their sensation matter; I can

therefore suppose, without recourse to abstraction, that sensation may exist even in the

absence of any perceptual consciousness to which it appears as a manifold “ordered and

situated in a certain form.” (A20/B34)

... Sensation, which exists already in synopsis, prior to and independently of pure intuition and

perception, has no ideality (see A28­9/B44); accordingly, that in appearances which

corresponds to sensation cannot be regarded otherwise than as “the transcendental matter of

all objects as things in themselves.” So, although in the absence of the pure forms of

appearances, space and time, inner and outer appearances would be totally annihilated,

sensation (the manifold given in synopsis) would not, nor would the transcendental reality that

corresponds to it be in no way concerned.” (Potter, J.).

This argument of interpretation rests on something that is actually quite simple, which is

the order in Kant’s philosophy in which things are given to and perceived and cognised by the

mind. If we did for a second not have the forms of space and time, then perception would be

impossible, for these give form to the manifold of sensation in a way that it can be perceived by

the mind. But since these are as lenses that we perceive sensations through, without which we

would be consciously blind to it, taking these forms of perception does not necessarily render

out of existence the sensations given to us, it just means that we cannot perceive them.

This argument seems to not require any of the type of abstraction that Berkeley criticizes as

invalid, because it supposes the continuation of existence of something which we perceive to

exist when our forms of intuition, Space and Time, are active, and which is perceived by us

through these forms of intuition when they are active. Sensations are not ideal, and can only be

brought to our awareness through the ideal a priori forms of our intuition. This does not allow us

to infer that these sensations are not present and affecting us when these intuitions are not

imposed on them by the mind.

In this way Kant’s response seems to not only hold within his own transcendental

philosophy, but also to take into account elements of Berkeley’s philosophy. This may make for

a more impartial or philosophically adequate response to Berkeley, building a bridge between

the two systems, bringing them under a same paradigm, and thereby allowing for a more

objective line of reasoning and refutation.

Even though I acknowledge that I am aware of the number of Kant scholars that have another

thousand differing views and interpretations on this matter, and that I’m not at all claiming that I

regard this interpretation and reading (for I know I would need years more of reading to properly

answer this question) as perfect, I will hold in this essay that this is the best aspect of the

Transcendental Aesthetic I could find to identify how Kant shows, defying Berkeley and the

thesis he attributes to the latter, that the existence of external objects is possible.

The Second part of this essay will briefly review Berkeley’s refutation of skepticism, and use the latter as an illustration of his point of view. This will come to show that it appears that

given his argument and a Kantian reading of it (which leaves out God and the role she fills), one

can only take from it that it is unnecessary and irrational to posit the existence of external

objects to explain our experience, and not as was given in the first part of the essay, that the

existence of external objects is impossible.

It is difficult to know exactly how far Berkeley thought his refutation of skepticism would

reach. It seems obvious that he was aiming to show that, given the foregoing defence of his

philosophical system, he wanted that to be enough to show that his Idealism is right, and that

nothing exists that is unperceived. In this way Skepticism is refuted by the collapse of the

‘representationalist’ gap between what is perceived and that which is, for they are both one and

the same (Berman 2010, p144) .

In the Three Dialogues between Hylas and Philonous, amongst other things, “Berkeley

aims to show both that some key doctrines of his philosophical opponents, whom he generally

terms “materialists”.actually lead to skepticism, which Berkeley interprets as evidence against

those doctrines of his opponents; and that Berkeley’s own philosophy contains the resources to

refute skepticism, not merely to avoid it” (Pappas 2008, p249). Berkeley oddly turns an

argument on its head, and uses the fact that other theories lead to skepticism as a refutation of

them, and the fact that his philosophy, according to him, avoids a skeptical outcome, as a

justification for its validity. This seems to be just another illustration of the general will of

philosophers to overcome skepticism, as well as holding their theories as valid, at any price,

including lines of reasoning which seem to not logically hold. Berkeley’s overarching argument

against skepticism is that his system renders it an improbable possibility, and that since other

systems allow more space for it, they must be in the wrong. What seems to happen in Berkeley

here can be illustrated through Peirce’ criticism of the Cartesian method of doubt, which can

extend to the way most philosophers handle skeptical critiques of their systems , and argue

against them:

“The assumptions with which we begin philosophy ‘are not to be dispelled by a maxim,

for they are things which it does not occur to us can be questioned’.This ‘initial scepticism will be

a mere self­deception and not a real doubt’. ‘No one who follows the Cartesian method will ever

be satisfied until he has formally recovered all those beliefs which in form he has given up.’

(Peirce 1992,pp.28–29).

It seems that Berkeley,at least in so far as he is understood by Kant, falls in this trap

when dealing with skepticism. His will to override skepticism is stronger than the importance that

he gives understanding the rational and logical grounds where this skepticism starts. He thus

uses the fact that skepticism is unreasonable and unnecessary (according to his Idealism), and

that so it is refuted. But this is not a logical argument that refutes skepticism, which is merely

sidelined rather than refuted.

Berkeley has one direct argument against skepticism. But this argument is regarded by most as

weak and problematic, if not flawed. Therefore his main argument against skepticism seems to

be that of this collapse of the ‘representationalist’ gap which renders the type of skepticism, that

of the impossibility of knowledge of ‘things in themselves’, absurd, because perceptions are

what constitutes reality, which is thus directly accessible for knowledge, and even by its very

nature is perceived, so in a way known. This seems rather like an argument for the improbability

of the existence of things in themselves, rather than an argument absolutely denying their

possible existence. Berkeley by first arguing for his own theory of Material Idealism, then uses it

to backup his claim that it is unnecessary and irrational to posit an external, unperceived,

non­ideal reality. Berkeley completes the ‘holes’ in his system with the mind of God, which

perceives everything whilst we are only perceiving in a finite way; in this way it allows Berkeley

to hold that ideas, that is the universe, do exist whilst we are not perceiving them, for they are

always perceived by God. But Kant does not take this into account as a philosophically valid

element of Berkeley’s system, for he wants to explain things without appealing to God, and so

he does not take into account this element that Berkeley could use in defence against Kant’s

attacks. It is thus important to note that in this third part, Berkeley’s philosophy will be

considered within the same confinements that Kant would have considered it when aiming to

refute it, that is without appeal to God’s infinite mind holding all ideas of perception persistently

and eternally, thus somewhat paralleling the role of an external mind­independent world.

The third part of the essay will thus complete Kant’s refutation of Berkeley’s Idealism,

through Kant’s Refutation of Idealism.

The previous part of the essay has defined our interpretation of Berkeley’s refutation of

skepticism as far as it seems to have a good philosophical grounding, in Berkeley holding that

positing the existence of an external,mind­independent world is unnecessary to explain our

experience of the world, that is perception and cognition of it.

Thus the second stage of Kant’s refuting Berkeley will be constructed as not only holding

as was shown in the first part, that the existence of external objects is possible, but moreover,

that their existence is necessary to make sense of our very experience.

The “Refutation of Idealism” is inserted into the discussion of actuality in ‘The Postulates

of Empirical thought’,in the second edition of the Critique (B 274­9). As Guyer & Wood say, “this

may seem like an inauspicious location for such an addition, but Kant’s intention in choosing it

can only have been to show that empirically meaningful judgements about modalities of

possibility and necessity all depend upon connection to the actual in perception”(Guyer & Wood

2009, p71). By the ‘actual in perception’, is meant:

“That which we judge to exist independently of our representation of it, even if we also

know that the form in which we represent the independence of such objects is itself dependent

upon the constitution of our own sensibility” (Guyer & Wood 2009, p71).

The Refutation of Idealism can be considered in two ways. Firstly as a refutation of

Cartesian Idealism, as it is formally presented by Kant; secondly as “Kant’s ultimate attempt to

prove that his idealism is merely formal idealism rather than the subjective realism of Berkeley”

(p72, Guyer & Wood).

Indeed, the refutation seems to be a reaction of Kant to the Gottingen Review of 1782, which

identified Kant’s idealism as of a similar type to that of Berkeley, something that Kant seemed to

want to avoid at all costs (Kuehn 2006,p638). Whether this was correct or not, and whether

Kant, if to stay consistent with his own premises and system, should indeed allow for this

possibility, and adhere to Berkeley’s type of idealism, is an important question, the next that this

essay should lead to but will not have the space for, that is whether it is consistent with Kant’s

system to assert the existence of external objects and whether in accordance with this he

should review the degree of skepticism he should accept.

Kant openly articulates in his presentation of the Refutation of Idealism that it is mainly

directed at Descartes’ “Problematic Idealism” (Kant 1787, B274), considering that Berkeley’s

“Dogmatic Idealism” has already been refuted in the Transcendental Aesthetic (Kant 1787,

B275).

But the ‘refutation of idealism’ can also be considered as completing the refutation of Berkeley’s

Idealism, for as is noted by Bryan Hall, “establishing the actuality of external objects is the

surest proof of their possibility” (Hall 2011, p130), or of as has been seen to possibly be a better

interpretation of Berkeley’s point of view which Kant want to refute, that there existence is

unnecessary and improbable considering our experience of the world. The Theorem of the Refutation of Idealism is expressed by Kant as follows: “The mere,

but empirically determined, consciousness of my own existence proves the existence of objects

outside me” (Kant 1787, B275). Basically, Kant wants to show that the existence of objects

outside of me is necessary for my own conscious experience, as necessarily determined in time

in order to be meaningful, and since I do, as Descartes agrees, undoubtedly have this very

consciousness, then objects outside of me must necessarily exist to make this possible.

The way that Kant proceeds in his ‘proof’ in the manner of a ‘transcendental argument’

is quite simple and succinct:

1. “I am conscious of my existence as determined in time” (B275).

2. “All time­determination presupposes something persistent in perception” (B275).

3. “This persisting thing, however, cannot be something in me, since my own existence in

time can first be determined only through this persisting thing” (B275).( It is here

important to note that according to Kant this cannot be the self, because the latter is an

empty notion that I must posit, but cannot identify or directly perceive).

4. “Thus the perception of this persistent thing is possible only through a thing outside of

me” (B275)

5. “Consequently, the determination of my existence in time is possible only by means of

the existence of actual things that I perceive outside me” (B275).

This argument is thus made to not only allow for the possibility of external objects, as is

defended in the Transcendental Aesthetic, but to show that the existence of external objects is

necessary for the very possibility of our conscious and ordered perception of the world as we

actually experience it, that is through the forms of our intuition, space and time. Time is the form

of our inner experience, Space is that of our outer experience. The point is that our ordering of

perceptions and our experience in time requires a constant, as some kind of reference point.

Kant’s view of the self may be important to include here, for he sees the self rather as a

necessary but empty subject, that one must posit, but cannot directly perceive­ therefore the self

as we experience it is actually just the thinking ‘activity’, that we experience through the unity of

apperception:

“The consciousness of myself in the representation I is no intuition at all, but merely

intellectual representation of the self­activity of a thinking subject. And hence this does not have

the least predicate of intuition that, as persistent, could serve as the correlate for

time­determination in inner sense, as, say, impenetrability in matter, as empirical intuition,

does.” (Kant 1787, B278).

Outer objects are thus necessary in two ways. The first is that they serve as a constant

in the way that there is always an external world, something experienced in space, without

which the inner form of time would remain undetermined:

“... This persisting element cannot be an intuition in me,. For all the determining grounds of my

existence that can be countered in me are representations, and as such they themselves need

something persisting distinct from them, in relation to which their change, and thus my existence

in time in which they change, can be determined” (Kant 1787, Bxxxix).

This argument then heavily depends on Kant’s identifying Space and Time as a priori

form of our Intuition. This apriority renders our perceptions into representations. This is what

differentiates Kant from Berkeley, for whom space and time were not a priori forms of our

intuition, but rather were part of the order of the world as we directly perceive it, the world as

‘esse’ and ‘percipi’. For Berkeley these forms are a posteriori, within what we experience; for

Kant they order our experience apriori, and thus our experience is made of representations that

conform to us, but that, as has been seen in the Transcendental Aesthetic, are as ‘filled ’by the

sensations, the matter of which is necessarily procured by external objects. Since the self is posited but cannot be known, for it is the knower, then it cannot serve as

the constant that is needed for the determination of things in time such as we actually

experience. All that I directly experience in myself is changing and representation, and so the

permanent, that I need to experience this determination in time, if not in me, “must be outside

me” (Kant 1787, Bxli). I must consider myself in relation to it, because this ‘myself’ is,

consciously,only a humean ‘bundle’ of representations, and thus has no permanent referent

within itself (Kant 1787, B xli). Now Kant wants to make sure to point out that “The

representation of something persisting in existence is not the same as persisting

representation”, for even if representation persists, its content can be very changeable (Kant

1787, B xli). We must therefore have the representations of things which persist in existence,

and these can only be made of sensations which are brought to us by something exterior and

persisting in its external existence­ external reality.

In conclusion, this essay has thus explored how, in a two­fold manner, Kant has aimed

to refute Berkeley’s idealism, or that is, the idea that Kant made of Berkeley’s philosophy and

its implications.The first stage was to show that, without appealing to pure abstraction, it is

possible, within a kantian transcendentally ideal system, to posit the possibility of external

objects, that is objects external to the mind. The second stage was to argue that the existence

of external objects must necessarily be posited to explain the very possibility of our experience

in the world of representations.

An interesting question to follow would be that of where this leaves Kant within his own

philosophy. Does the fact that Kant refutes Berkeleyan Idealism leave more space than

wanted to the skepticism that Berkeley had claimed to refute in advancing this very same

Idealism? One of the main criticisms that Kant’s philosophy has received is the fact that, working

within its own confines, Transcendental Idealism does not leave any valid place for Kant’s

inferences about the ‘thing in itself’. By differentiating himself from Berkeley, Kant does leave

space for skepticism within what Berkeley named the ‘representationalist gap’ which collapsed

under Berkeleyan Idealism. This space for a skeptical view seems much wider than what Kant

would like to allow for within his philosophy, given his apparent ambitions to override such

skepticism through arguing for his Transcendental Idealism.

Bibliography: . Berkeley, G. (1710), Principles of Human Knowledge, in Principles of Human Knowledge and Three dialogues (1988), Woolhouse, R. (ed) Penguin Books, England. . Berkeley, G. (1713), Three Dialogues between Hylas and Philonous, in Principles of Human Knowledge and Three dialogues (1988), Woolhouse, R. (ed) Penguin Books, England. . Kant, I. (1781­1787) Critique of Pure Reason, in Guyer, P. & Wood, A.W. (eds and translators) (2009), The Cambridge edition of the works of Immanuel Kant: Critique of Pure Reason, Cambridge University Press, USA. . Kant, I. (1783), Kant’s Prolegomena to any future Metaphysics, edited in English by Paul Carus (1949), The Open Court Publishing Company, USA. . Berman, D. (2010) The Distrustful Philosopher: Berkeley Between the Devils and the Deep Blue Sea of Faith, in Parigi, S. (ed)George Berkeley: Religion and Science in the Age of Enlightenment, Springer, pp. 141­158. . Hall, B. (2011) The Arguments of Kant’s Critique of Pure Reason, Lexington Books, USA. . Kuehn, M. (2006) Kant’s critical philosophy and its reception­the first five years (1781­1786), in Guyer, P. (ed) The Cambridge Companion to Kant and Modern Philosophy, Cambridge University Press, USA (pp.630­664). . Gardner, S. (1999), Kant and the Critique of Pure Reason, Routledge, Great Britain. . Pappas, George (2008) , Berkeley’s treatment of skepticism, in Greco, J (ed) The Oxford Handbook of Skepticism, Oxford University Press, USA. pp. 249­264. . Peirce, Charles S. (1992) The Essential Peirce. Vol. 1. Nathan Houser and

Christian Kloesel (eds), Indiana University Press, USA. . Potter, J. ­ University Colorado Boulder. Permanent link to the lecture referenced: http://www.colorado.edu/philosophy/potter/Kant%20Lecture%204.pdf. . Waxman, W. (2014) Kant’s Anatomy of the Intelligent Mind, Oxford University Press, USA.