Chapter 1

The Fundamental view of idealism

Objectivity and Conceivability

 

1.1 Kant’s Transcendental Idealism

In The Critique of Pure Reason Kant addressed the problem of objective validity.  He set himself the task of investigating what it meant for a concept to be valid such that genuine knowledge might arise from its application in judgement.  One way of gaining knowledge about the world is to derive concepts from experience, and to apply them within experience.  This is the usual method, for example, for discovering the contingent propositions of the sciences.  On the other hand, certain concepts and the propositions derived from their application, have the status of being a priori, of not being so derived from experience.  Both mathematics and physics contain a priori concepts and judgements; the former being a thoroughly a priori discipline in its pure form, and the latter having certain a priori concepts embedded in its basic principles.

Kant’s primary concern was with what he called synthetic a priori judgements: judgements that provide objective knowledge, which are nevertheless made independently of any particular experience.  Synthetic judgements are contrasted with analytic judgements, which proceed purely by analysing the concept involved.  This analysis shows that the concept contains the predicate that is judged of it.  Thus, logical reasoning proceeds analytically on the basis of the law of non-contradiction[1], while empirical propositions, which are not merely an analysis of the concepts involved, are synthetic.  One way to put this distinction is to say that synthetic judgements generate knowledge, while analytic judgements only expand on that which is already known (in the sense that the judged predicate is already contained in a concept which one already has mastery over).  Synthetic a priori judgements are therefore intended to provide genuine knowledge, while being based on pure reason rather than experience.  Such is the task of metaphysics.

The necessity to examine the possibility and foundations of synthetic a priori knowledge was made all the more pressing by Hume, whose critical attention to experience had found it unable to support the propositions of metaphysics.  He could not find anything in experience that justified such basic metaphysical assertions as “every event has a cause”.  Supposing that all a priori propositions were analytic, and that the propositions of metaphysics were not, he concluded that the latter were based on psychological habit rather than sound reasoning.  This sceptical conclusion overlooked the possibility, however, that propositions might be both synthetic and known on a priori grounds.  Kant therefore placed special emphasis on the notion of the synthetic a priori, since he held that judgements of this kind were known to exist in the form of mathematics.  While we know that 5+7=12 on a priori grounds, Kant claimed that this knowledge could not be gained analytically.  He contended that the concepts of 5, 7 and addition could not be said to ‘contain’ the concept of 12.  Such mathematical propositions must therefore fall into the synthetic a priori category.  An explanation of how such propositions are possible thus became of paramount importance to philosophy, and Kant’s central question of The Critique of Pure Reason was “How are synthetical a priori judgements possible?”[2]  How could pure reason transcend the limits of experience, while still providing knowledge?  If this could be solved for mathematics, then we might gain some insight into how to do metaphysics.

It was Kant’s radical solution to this problem that gave his philosophy its idealistic nature.  He ventured to produce what he called “the Copernican revolution in philosophy” by questioning one of the most fundamental assumptions of metaphysical thought.  He questioned the assumption that our knowledge must conform to objects, and suggested that more progress might be made if we thought of things the other way about: that objects must conform to our knowledge.

Kant explored this novel approach by making a distinction between things as they appear, or ‘phenomena’, and ‘things as they are in themselves’, or ‘noumena’.  This is not to be confused with a distinction that is commonly made between how things seem and how they really are (according, say, to some completed scientific theory), or between representation and thing represented.  (A distinction of the latter kind does indeed underlie a kind of idealism — Berkeleian idealism.  We shall return to differences between this doctrine and Kant’s below).  Phenomena are not our (mental) representations, but that which must conform to our representations[3].  By requiring that objects must thus conform, the problem of knowledge a priori of these objects becomes soluble: we can know a priori the contribution that our own nature makes to synthetic knowledge.  That is, we can investigate the conditions on which the possibility of knowledge rests.  This investigation, which Kant calls a ‘transcendental inquiry’, is supposed to reveal how concepts and formal intuitions (forms of experience) that are not derived from experience, are nevertheless to be found within experience, as part of its structure.  They are presupposed by experience, and according to Kant, the possibility of their application as a priori knowledge can be revealed by a critical examination of the nature of experience and its conditions.[4]

This critical examination has two parts, which correspond to the different kinds of explanation Kant thought were needed for the synthetic a priori: in mathematics on the one hand and metaphysics on the other.  The first part, presented in the Transcendental Aesthetic, deals with the formal ‘intuitions’ of time and space, which provide the basis of mathematical and geometrical reasoning.  This is an analysis of ‘sensibility’, the ability to receive representations by being affected by objects.  The second part, presented in the Transcendental Analytic, gives an analysis of the ‘understanding’.  Objects are ‘given to us’ through sensibility, but they are only thought about by means of the understanding, which is the source of synthetic a priori concepts.  Both the faculty of sensibility and the faculty of understanding play necessary roles in experience, which is a synthesis of the two.  “Without sensibility no object would be given to us, without the understanding no object would be thought.  Thoughts without content are empty; intuitions without concepts are blind.”[5]

The Transcendental Analytic presents the categories that are employed by the understanding, and argues that their employment is the source of synthetic a priori knowledge.  These categories are the twelve ‘pure’ concepts of the understanding.  Our ordinary concepts are determinations of these pure concepts.  The concept of a book, for example, is a determination of the concept of an artefact, which in turn is a determination of the category of a substance.  In this way, at least one of the categories is employed in any judgement.  So if knowledge involves judgement, there can be no knowledge that does not involve one or more of the categories.  This already makes them an integral part of what it is to have knowledge of the world, for that world must conform to the categories in order to be known.  For Kant it is a fact, therefore, that knowledge involves certain concepts, and these concepts can be known on purely a priori grounds.  But Kant’s justification of their employment does not end there.  He argues in the Transcendental Deduction that not only is it a fact that we do and must use the categories, but that we also have a right to do so[6].  That is, he argues that the world must be such that it really does conform to the categories.

So transcendental idealism involves an analysis of what it means to have knowledge and experience of an objective world.  The analysis of the understanding is supposed to say something about what it means to make judgements: it involves, or presupposes, certain categories.  It is important to Kant’s project that these categories constitute synthetic a priori knowledge that is objectively valid.  No only was the analysis supposed to hold for the notions of judgement and knowledge in general (or at least as far as those notions are comprehensible to us) but he argued separately for their objective validity in the Transcendental Deduction.

This view of transcendental idealism, with it emphasis on objectivity and the world, is not the only view however.  Schopenhauer considered himself the true heir of Kantian philosophy, and yet he criticised Kant for neglecting the fundamental truth of idealism.  So I will turn now to a discussion of his work in order to investigate the fundamentals of idealism, and how it relates to transcendental idealism.

1.2 Idealism in Schopenhauer, Kant and Berkeley

Schopenhauer begins his principal work[7] by expounding “On The Fundamental View of Idealism”.  He urges that the world as it is known has been shown through modern philosophy, especially through Berkeley and Kant, to be only a “phenomenon of the brain”, encumbered with subjective conditions.  Thus, “the world is my representation” is the first axiom of Schopenhauer’s metaphysics.  He takes his cue in part from Descartes, who, recognising the role of the intellect in moulding the world, made his starting point in philosophy here with his cogito ergo sum.  Thus what is most certainly and immediately known is one’s own consciousness.  For this reason Schopenhauer endorses Berkeley’s idealism.

The idealistic starting point is taken as an attempt to ensure truth and certainty in philosophy.  The greatest influence on Schopenhauer was Kant, whose project was, as we have seen, to discover firm foundations for philosophy.  But Schopenhauer saw no conflict between Transcendental Idealism and Berkeley’s idealism, despite the fact that Kant did.  Schopenhauer accepted the propositions of the Transcendental Aesthetic, which presents Kant’s first and perhaps most radical statement of Transcendental Idealism, as numbering “among the incontestable truths”[8].  And while he claims that the Antinomies do not provide the proof that Kant intended, that the objective order in time, space, causality, matter etc. cannot even be conceived as a self-existing order, he nevertheless accepts his conclusion.  He goes on to say that, “Kantian teaching, even without the antinomies, leads to the insight that things and their whole mode and manner of existence are inseparably associated with our consciousness of them.”[9]   

True idealism, for Schopenhauer, is ‘transcendental’, but he takes the idealism of Berkeley to be included under this title as well as Kant’s.  Both “leave empirical reality untouched”[10], but differ in the way in which they claim objective reality, (hence the empirically real in general), is conditioned by the subject:

(1) “Materially, or as object in general, since objective existence is conceivable only in face of a subject and as the representation of a subject.”  This corresponds to Berkeleian idealism.

(2) “Formally, since the mode and manner of the object’s existence, in other words, of its being represented (space, time, causality[11]), proceed from the subject, and are predisposed in the subject.”  This is attributed to Kantian idealism.

Both kinds of idealism are implied when he claims “the objective existence of things is conditioned by a representer of them, and that consequently the objective world exist only as representation”.  The representation of the subject, is “conditioned by the subject, and moreover by the subject’s forms of representation, which belong to the subject and not the object.”  Thus, for Schopenhauer, the most important aspect in transcendental idealism is a general recognition “that things and their whole mode and manner of existence are inseparably associated with our consciousness of them.”

In trying to reconcile these two approaches, Schopenhauer’s work obscures some important differences that I would like to examine.  The true nature of Kant’s Transcendental Idealism is done violence in overlooking the important differences between it and Berkeley’s empiricism.  Having given attention to these differences, we will be in a stronger position to consider the real nature of transcendental idealism, and how it is related to the fundamental view of idealism.

Kant’s philosophy famously arose as a considered reaction to the two predominant philosophical schools of thought of his time: the empiricism of Hume and Berkeley on the one hand, and the rationalism of Leibniz and Wolff on the other.  The dispute between them can be characterised with the question, “How can we know the true nature of things?”  The empiricist responds with an appeal to experience, the rationalist with an appeal to reason.  The Critique of Pure Reason can be seen as an attempt to both reconcile and criticise these two positions by answering the question in a novel and ingenious way.  One must understand the originality and significance of this answer if one is to understand what Kant meant by ‘transcendental idealism’, and the affect this idealism had on twentieth century analytic philosophy.

The problem that both empiricists and rationalist were responding to derived its distinctive character from Descartes’ methodological scepticism.  The question becomes, “How do we know that the world really is the way it appears to us?”  Indeed, in his Meditations Descartes’ scepticism even extends to the very existence of the objective world beyond appearances.  The empiricist takes this scepticism seriously, and in the philosophy of Hume and Berkeley, we find a denial that there is anything known about that which is beyond experience, or even that it makes sense to speak of such things.  For if all objective knowledge (i.e. knowledge of what there is, or of which concepts are ‘objectively valid’) comes to us through experience, how could that knowledge ever transcend experience?  We are left with an impoverished conception of reality, containing only minds[12] and mental entities.  The rationalist, on the other hand, puts his faith in reason, and following Descartes, uses it as a tool to investigate the ‘true nature’ of things.  Leibniz made extensive use of this tool, and developed a philosophy of metaphysical individuals (‘monads’) that were known by reason alone, and thus did not bear a straightforward relationship to the mere appearances found in experience.  It was this metaphysical picture that Kant subscribed to, until Hume’s scepticism shook it to its foundations.  On what grounds is this faith in pure reason justified?

Superficially, Kant’s response had much in common with the empiricism of Hume and Berkeley.  Reason must somehow be constrained by experience, and one way it can be so constrained is by applying its concepts only within experience.  Kant follows the empiricist in claiming that the only objects that we can refer to are possible constituents of sense-experience.  Unique to the Kantian response, however, was the provision for a further way that concepts might be objectively valid.  A concept is to be considered objectively valid if it is a transcendentally valid concept, that is, one that is derived by considering the necessary conditions for human experience to be as it is.  This new grounding for synthetic a priori knowledge allowed him to argue for a position that is distinct from both the empiricist idealism of Hume and Berkeley on the one hand, and the speculative rationalism of Leibniz and Wolff on the other.  He developed transcendental arguments against the Cartesian dualism that brought about scepticism about the external world, and thus challenged the notion of experience that brought Hume to his sceptical conclusions.

While nothing can be known of the thing-in-itself, the elusive reality beyond the subjective conditions of experience, this should not be taken to deride the knowledge of ‘mere phenomena’ that we gain through experience.  His philosophy involves a rejection of the separation of the world as it is from our experience of it.  He attempts to overcome this dualism by arguing that appearances and objects are not two distinct kinds of entities, but are such that they can only be understood in relation to each other.  The world is necessarily capable of being experienced by us, and we can describe appearances only in so far as they are appearances of an objective world[13].  Thus Kant rejects the epistemological dualism that underlies the philosophies of his predecessors.  This dualism of world and experience is connected with ontological dualism, which postulates a Cartesian ego that separates the private world of experience from the objective world external to it.  Kant also rejects ontological dualism.  The subject is not a part of the objective world, as the Cartesian ego is, but one of the transcendental conditions of that world.  However, simply rejecting the ego as a substance is not enough to free one’s philosophical investigations from epistemological dualism.  Hume also rejected the Cartesian ego, on the basis that nothing that he found within his experience corresponded to it, but still found ‘himself’ trapped within that experience.  Nevertheless, ridding one’s philosophy of the Cartesian ego is an important part of escaping from the limitations of our consciousness.  Hume and Berkeley differ from Kant in a very import respect.  They assume we have access only to ideas (the contents of our minds) rather than to a (phenomenal) world that is in some sense ‘external’ to our minds.

In what sense external?  Part of the answer to this question lies in the fact that Kant makes a distinction between the representation of sensibility and the object of that representation which is known through the understanding.  In his critique of Kant[14], Schopenhauer rejects this distinction, referring the reader to both Berkeley’s and his own discussion of idealism[15].  And this rejection is connected with Schopenhauer’s rejection of the Transcendental Analytic, which deals with the categories.  All but one of them is rejected, and only the category of causality remains in Schopenhauer’s metaphysics.  He argues, perhaps rightly, that causality cannot be dealt with separately from sensibility, as it is in Kant’s philosophy, for it is required in perception.

In so emphasising the importance of perception, Schopenhauer’s rejection of a separable role for the understanding brings him closer to the idealism of Berkeley.  The sole role of the understanding is the application of the law of causality in order to derive a cause of the sensations within experience.  This cause is both object and representation of the subject: object because it is taken to be cause of sensation, and representation because the law of causality is of “subjective origin, just as is the sensation itself”[16].  He goes on to claim that Kant’s confusions on this matter were due to “his fear of Berkeleian idealism”[17].

But Kant was not just motivated by a mere fear or aversion to Berkeleian idealism.  It was part of his purpose to refute it.  Specifically, he wished to defend the idea, attacked by Berkeley and Hume, that certain notions, such as (non-mental) substance, are objectively valid.  The separation of the object from the representation in Kant’s philosophy is part of this defence.  While Berkeley infamously claimed that to exist is to be perceived, Kant’s idealism claimed only that to exist is to be perceivable.  I take it that this is one of the consequences of the ‘idealism’ of the Transcendental Aesthetic.  To exist (as phenomenon) is to be in time and space, and since these are ‘forms of intuition’, being in them entails that something can be the object of intuition [perception].  This may seem a contentious claim to the modern scientist (who posits imperceptible sub-atomic entities[18]), but it is nevertheless at least minimally realist: objects are not dependent on actually being perceived.

Now while Schopenhauer may well have been right to question the distinctness of the sensibility and the understanding, the Berkeleian conclusions he draws do not follow from this criticism alone.  The same distinction has been criticised by a range of commentators of Kant’s work, from Hegel to the modern day.  Politis, for example, refers to the distinction as the “Achilles heel of the Critique.”[19] But this rejection is seen to have very different consequences.

Politis’ concern is that a separate treatment of the sensibility leaves Kant open to the charge of not succeeding in his effort to free himself from phenomenalism.  The separation of sensibility and understanding implies that we can refer to objects within sensibility alone, and this is at odds with Kant’s claim (in the Analytic of Concepts) that a phenomenal language is not sufficient to describe our experience.  To do this we must make judgements on how things or substances are, and this is not possible with the use of a language that refers only to the fleeting objects of phenomenal experience.  Kant was aware that the separation of the understanding from sensibility left open the possibility of phenomenalism: that experience was independent of our concepts.  Such a possibility, with the corresponding threat of Humean scepticism, was the target of the Transcendental Deduction.  The details of this argument are obscure, and for this reason alone it has been found less than convincing.  But the general strategy used by Kant contains a simple and powerful idea.  In order to pose the question of whether the world is as it seems, the sceptic must have a certain point of view on the world.  He must be able to identify his experiences as his experiences.  It must be the case that the thought ‘I think’ can be prefixed to all of his thoughts and representations.  This fact, which Kant called the “transcendental unity of apperception”, is a transcendental fact: it is a subjective condition of experience.  From this subjective condition Kant argued, though perhaps with some difficulty, for an objective world: a world that necessarily can be different from the way it seems.  He argued that, as a reflector on self-conscious experience, I could have no knowledge of experience without assuming that I persist in time, and that my experience is of objects that persist independently of me.  What I experience is not merely sensation, but an objective world that must be described with the use of certain categories, such as enduring substance and causality.[20]  Kant went on to argue[21] that “our internal and, to Descartes, indubitable experience is itself possible only under the previous assumption of external experience.”

So while the categories, like the ‘pure intuitions’ of time and space, were granted a subjective status by Kant, it is important to consider the nature of this subjective status carefully.  As already discussed, it was part of this idealism not to confine the phenomenal world to a mental realm.  Rather, he aimed to show that the subjective and the objective ways of describing experience are not independent of each other.  And this dependence goes both ways.  While subjectivity is formulated as the conditions of experience, that experience cannot be described without it being experience of an objective world.  A world that may be different from the way it seems.  This emphasis on the dependence of subjectivity on objectivity constitutes a rejection of Cartesian dualism.  Experience is not confined within a ‘private realm’ of the mind, since it presupposes the public world it is experience of.  The idea of an ego, an object that is both within the world, and yet separated from it, is rejected as a ‘paralogism of pure reason’.

The point about the categories and the pure intuitions being of subjective origin was not to reject a world external to our minds, but to show that this world is not independent of the subjective conditions of knowledge.  His aim was to demonstrate the possibility of objective a priori knowledge of this world.  Kant rejects the suggestion that any ideality belongs to other representations, such as sensation, for sensation does not provide us with objective a priori knowledge[22].  If subjective forms of intuition are to provide us with knowledge that is truly objective, then the object must be regarded as distinct from the subject, and yet its form must be dependent on the form of objective knowledge in general.  The object is not merely ‘my representation’, for it is not dependent on me for its continuing existence.  If I ceased to exist, the object would not thereby disappear.

Kant’s purpose was to show that certain concepts that we possess a priori are nevertheless objectively valid, and that the way things seem to us does in fact provide us with real knowledge.  As he put it in the Transcendental Aesthetic, appearance is not mere illusion, for a proper conception of experience presupposes that our representations are of something external to our minds:

For in an appearance the objects, nay even the properties that we ascribe to them, are always regarded as something actually given…[23]

Furthermore, the ideality that Kant ascribes to time and space is supposed to support the idea that the objects that appear in them are ‘real’ (i.e. not illusory):

It is only if we ascribe objective reality to these forms of representation that it becomes impossible for us to prevent everything being thereby transformed into mere illusion.[24]

His point seems to be that if time and space “inhered in things themselves” then they would become strangely incoherent: both necessary for, and external to, experience.  In which case the objects we were aware of would have to be regarded as merely (made up of) mental entities, and we would not be able to “blame the good Berkeley for degrading bodies to mere illusion.”

It seems to me that Schopenhauer did not see the central importance of some of these ideas because he interpreted Kant as reacting first and foremost to the “dogmatic philosophy” of his rationalist predecessors.  This was only part of his project, which could be characterised more correctly as a middle way between sceptical empiricism and speculative rationalism.  In addition, Schopenhauer failed to see the importance of the rejection of Cartesian dualism for this project.  It was the underlying assumption common to both empiricism and rationalism that set up the problem they were trying to solve: “How do we know that the world really is the way it appears to us?”  It is this rejection of the sharp distinction between experience and objective world that most strongly characterises transcendental idealism, which ultimately claims both that the world is the way we experience it, and that we experience it the way it is.

1.3 Three Kinds of Idealism: Empirical, Transcendental and Conceptual

Idealism is a doctrine of dependence.  It can be variously characterised as asserting dependence between world and mind, object and subject, or objectivity and subjectivity.  None of these characterisations make clear a particular view without a further explanation of the terms involved, and most importantly, a further explanation of what is meant by ‘dependence’.

There is in Schopenhauer and Berkeley a dependence between object and subject that is best characterised as existential or empirical.  That is to say, the continuing existence of a particular object is dependent on the continuing existence of a subject as a substance.  The subject plays this supporting role as a particular in the world.  It is a dependence between contingent states of affairs.  This is evident from the conclusions they draw from certain arguments.  Berkeley’s so-called ‘Master Argument’, for example, claims that we can no more conceive of something existing unconceived than we can see something unseen:

HYLAS.  …What more easy than to conceive a tree or house existing by itself, independent of, and unperceived by any mind whatsoever? I do at this present time conceive them existing after that manner.

PHILONOUS.  How say you, Hylas, can you see a thing which is at the same time unseen?

HYLAS.  No, that were a contradiction.

PHILONOUS.  Is it not as great a contradiction to talk of conceiving a thing which is unconceived?

HYLAS.  It is.

PHILONOUS.  The tree or house therefore which you think of, is conceived by you.

HYLAS.  How should it be otherwise?

PHILONOUS.  And what is conceived, is surely in the mind.

HYLAS.  Without question, that which is conceived is in the mind.

PHILONOUS.  How then came you to say, you conceived a house or tree existing independent and out of all minds whatsoever?[25]

Note that Berkeley begins with a claim about the inconceivability of something unconceived and concludes that it must be existentially dependent on a mind — that it must exist in a mind.  Schopenhauer offers a similar argument:

That the objective world would exist even if there existed no knowing being at all, naturally seems at the first onset to be sure and certain, because it can be thought in the abstract… But if we try to realise this abstract thought, in other words, to reduce it to representations of perception, from which alone (like everything abstract) it can have content and truth; and if accordingly we attempt to imagine an objective world without a knowing subject, then we become aware that what we are imagining at that moment is in truth the opposite of what we intended, namely nothing but just the process in the intellect of a knowing being who perceives an objective world… and so in the assumption that the world as such might exist independently of all brains there lies a contradiction.[26]

Again we start from the natural thought that things could exist unconceived, followed by a questioning of the validity of this assumption on the basis of a conceivability (i.e. imaginability) argument, and finally we have an existential dependence claim drawn from this argument.  The conceivability argument used by Schopenhauer, like the one used by Berkeley, involves an appeal to perception, but whereas Berkeley’s appeal is by way of analogy, Schopenhauer’s is more direct.  He claims that the content and truth of an abstract thought must come from its realisation in the representations of perception.

Both arguments share some serious problems.  For example, both are apparently far too strong, in that if they work, they prove far more than their authors intended.  It is true that I cannot see a tree that is unseen, but if this analogy carries over to the case of what is conceivable, then why not the fact that I cannot see any tree that is not seen by me?  This thought brings us to the unhappy position of solipsism, for I cannot conceive, on Berkeley’s and Schopenhauer’s notion of conceivability, of anything that is not conceived by me.  Berkeley only avoids solipsism by an appeal to the mind of God, but it seems that I can no more conceive of something conceived by God but not me than I can conceive of something unconceived by any mind.  Indeed, the mind of God itself is quite unimaginable to me, and so would be excluded from existence by Berkeley’s own reasoning[27].  Schopenhauer also rejects solipsism, but offers no argument for this rejection.  He merely claims that those convinced of its truth must surely be confined to the madhouse, but admits that “theoretical egoism”, as he puts it, is irrefutable[28].  He should have done more to defeat it, for if it is implied by his philosophy, this can only tell against it.

This unwanted solipsism is implied by the notion of conceivability used by Berkeley and Schopenhauer.  On this notion, if I imagine anything, I must count myself, as knowing subject or mind, as part of what is imagined.  A defender of realism might question this notion of conceivability.  This is the position taken by Bernard Williams in ‘Imagination and the Self’[29], where he argues from analogies between the act of imagining and the act of watching a theatrical performance such as a play or film.  When one watches a play, there is a very real sense in which one sees the events and characters that form the elements of the play.  One ‘sees’ Othello, and one ‘witnesses’ Othello strangling Desdemona.  Yet these truisms involve a deviant use of ‘sees’ and ‘witnesses’ that is analogous to changes of meaning when one talks of ‘seeing’ in the case of imagination.  What one sees when one attends a performance of Othello is a cast of actors and actresses playing the parts of characters in a play.  While Emila discovers Desdemona’s dead body, it does not follow that the actress who plays her then sees a dead body, and neither do the audience.  If we follow this line of argument, we come to the conclusion that one can conceive of something unconceived[30], for one is not necessarily part of what is imagined, even as subject.

Williams’ point is well taken, for what I imagine does not include me.  If we accept Hume’s insight that no part of one’s experience corresponds to the subject, then it follows that no part of one’s imagination corresponds to the subject.  I am not a necessary part of the content of what is imagined.  So it cannot be the case that such conceivability arguments of the kind put forward by Berkeley and Schopenhauer show that minds must exist in the world in order for objects to exist.  In fact, despite Schopenhauer’s conclusion that the world depends on the operation of brains, his discussion of the dependence between subject and object often sounds more conceptual[31] than existential.  Insofar as the knowing being appears as object, he would have to concede that it could be eliminated from our imagination.  And what is left when we remove the self that is known as object?  It cannot be the Cartesian ego, for that is supposed to be some kind of object in the world[32].  The Kantian alternative is that it is just the transcendental conditions for a world that can be known and experienced.  But if such conditions are not to be considered as objects in the world then nothing can be existentially dependent on them.  Existential dependence, if it is to make any sense, must be a relationship between particulars.  To say that something is existentially dependent on something else implies that both entities could come into and pass out of existence.  At least, it is extremely unclear what it would mean for something to depend for its existence on something that was outside time and space.  It cannot mean, as Schopenhauer suggests, that if the conditions ceased to be, then so would the dependent entity, for it makes no sense to talk about timeless conditions ceasing to pertain[33]. 

Concentrating on Schopenhauer’s claims of existential dependence may, in any case, produce a misleading picture of his philosophy.  His love of flamboyant language and powerful imagery obscures what this existential dependence is supposed to consist in.  It is a dependence that occurs on the ‘transcendental level’, and it is not clear what this means (and is not much clearer in Kant’s work) but it is supposed to imply that it leaves empirical truths untouched.  The coming into being and passing away of things, and the dependencies between such events, surely constitute empirical facts.

Kant comments in the appendix of the Prolegomena that he would rather that transcendental idealism were known as “‘formal’ or, better still, ‘critical’ idealism, to distinguish it from the dogmatic idealism of Berkeley and from the skeptical idealism of Descartes.”[34] In what does its being formal or critical consist?  Part of the answer lies in Kant’s repeated insistence that the analysis of the understanding is not a kind of empirical psychology.  He was not offering a theory of how the human mind makes judgements, but rather an analysis of what it is to make judgements at all.  The dependence between subject and object is not existential, between actual minds and particular objects, but formal, between concepts and their objects.

One way to put this is to say that Kant was interested in the relationship between ‘thought’ and the world.  The objects of knowledge must conform to the structure of thought, but the world would continue to have that structure if every thinking being were eliminated from it.  We can think of thought in this sense as independent of empirical psychology.  It is tempting then to think of idealism as asserting an existential dependence between thought and the world.  But to think of this as an existential dependence is to introduce strange Platonic entities, both abstract and existent, that are simply not needed.  Indeed, this seems to be a case of applying the concepts of the understanding without regard to the limitations of experience that Kant was at such pains to delineate[35].  The temptation to posit them stems, I think, from a tendency to model all dependence in terms of dependence between objects (as the body is dependent on the heart).  This, it seems to me, is the real root of confusion in Schopenhauer’s treatment of idealism.

Kant was engaged in an analysis of how concepts are employed in knowledge, and his work was based on the idealistic assumption that the natures of things as they are known are not independent of our ways of knowing about them.  Thus Kant was engaged in a conceptual analysis that placed epistemology at its foundation.  This approach to conceptual analysis has been largely rejected by analytic philosophy, which has rejected the ‘psychological idiom’ and emphasises the philosophy of language rather than epistemology.  We might note, however, that Kant himself considered his method to be closely connected with linguistic analysis.  He comments in the Prolegomena that the analysis of a priori concepts “presupposes neither greater reflection nor deeper insight than to detect in a language the rules of the actual use of words generally and thus to collect elements for a grammar”.  While his inquiry is primarily an analysis of knowledge, rather than language, he acknowledges that “both inquires are very closely related”[36].

Let us take the term ‘conceptual dependence’ to mean a dependence between concepts.  Thus there is a conceptual dependence between the concept ‘substance’ and the concept ‘table’: the latter being a subcategory or determination of the former.  No doubt there are other kinds of conceptual dependence.  Analytic dependence (containment) and synthesis (as some kind of combination) are both candidates.  But we might also take the term ‘conceptual dependence’ to include dependences between concepts and objects.  Take the ‘form’ of an object be the concept or intuition that corresponds to it.  Then we can use the term ‘formal dependence’ to mean a conceptual dependence between a concept and the object, property or fact it picks out, such that there is a formal dependence between any object (property / fact) of kind A and the concept C that picks it out as an object of kind A.  When we think about a table as a table, we necessarily employ the concept ‘table’ (and, by implication, the concepts on which ‘table’ conceptually depend, such as ‘substance’).  The concept C tells us something about the kind A.  The nature of an object is thus dependent on the sortal concepts that correctly individuate it.  So, on Kant’s view, all phenomenal objects are formally dependent on the categories and the forms of time and space.  And that is to say that the natures of objects are in part prescribed by certain abstract conditions.  Note that while the dependence relation in Berkeley and Schopenhauer is between contingent states of affairs, this is not the case for conceptual dependence.  This is because concepts and intuitions do not have to be regarded as contingent particulars, but can be regarded transcendentally as the conditions for thought (regardless of whether any being happens to fulfil those conditions).

We might say that at the heart of Kant’s Transcendental Idealism is a doctrine of formal (and other conceptual) dependence.  While describing Kant’s philosophy in such terms is a somewhat incomplete characterisation of Transcendental idealism, it does allow us to see how it is related to what I shall call ‘conceptual idealism’, the doctrine that the world is limited by our possible concepts.  A full discussion of this view will have to wait until chapter 3, but we can already point out some differences between it and Kant’s idealism.  Both the acceptance of the thing-in-itself and the role of the given in Kant’s philosophy, however restricted, set his doctrine apart from conceptual idealism.  These two conceptually real aspects of Transcendental Idealism are related.

Let us take first the notion of the noumenal world.  In Kantian philosophy, the world limited to our possible concepts corresponds to what he calls the ‘phenomenal’ world.  Kant contrasted this world with the ‘noumenal’ world, which is independent of the understanding and the subjective conditions of knowledge.  One way to view transcendental idealism is as a combination of conceptual idealism (with respect to the phenomenal world) and conceptual realism (with respect to the noumenal world).  The acceptance of the thing-in-itself represents a departure from full idealism, though the extent of this departure is not altogether clear from Kant’s work.  Conceptual idealism is committed to saying that it makes no sense to refer to that which is independent of our concepts.  The true nature of reality is not hidden by our inability to comprehend it.  This mistaken way of thinking comes about by thinking of ‘true reality’ as something independent of our concepts: a ‘pre-conceptualised reality’ that we must ‘interpret’.  According to conceptual idealism, nothing corresponds to this empty conception of an independent reality of things-in-themselves.

If the categories provide the concepts of thought, the role of the given will also make Kant’s philosophy distinct from conceptual idealism.  The given is not subject to such transcendental conditions – hence Kant’s insistence that no ideality belongs to sensation.  While Kant argued in the transcendental deduction that we cannot make sense of the unity of experience simply in terms of the given, he still saw the given as something that imposed upon the sensibility.  His point in the transcendental deduction was that this was not a sufficient characterisation of experience.  But since the given is formed by the sensibility and synthesised by the understanding, it is not understood as having conceptual form prior to apperception.  This again brings Kant into opposition with the conceptual idealist.

One way to view the relationship between Transcendental Idealism and conceptual idealism is in terms of the critique of the separable treatment of the sensibility and the understanding that I discussed in the previous section.  We noted that this separable treatment has also been stoutly criticised by many other commentators on Kant, from Hegel to the present day.  One of the consequences of this rejection, acknowledge by Schopenhauer, is that there is no longer scope for a pre-conceptual ‘given’ that impinges on the faculty of sensibility.  But there is also a consequence that was not anticipated by Schopenhauer.  For one may draw conclusions about the very notion of the noumenal, which is beyond our power to objectively apply the categories of the understanding.  Kant maintained that, while we could have no knowledge of the ‘thing-in-itself’, noumena are nevertheless ‘intelligible’.  According to Kant, the understanding “problematically” extends further than sensible intuition, “but we have no intuition, indeed not even the concept of a possible intuition, through which objects outside the field of sensibility can be given, and through which the understanding can be employed assertorically beyond that field.”[37]  Thus we can think, but have no knowledge, beyond the limits of sensibility.  But then to question the separation of the understanding from the sensibility is also to question the notion of noumena.  If one replaces the analysis of the faculties of understanding and sensibility with a single analysis of, say, conceptual experience, one has no understanding left over, so to speak, to make ‘noumena’ intelligible.  This thought leads to philosophies that not only limit knowledge within the bounds of sensibility, but also limit truth and thought within those bounds[38].  Conceptual idealism sees experience and the world as essentially conceptual.  We cannot make sense of something without conceptual form (such as the so called ‘given’) or something existing outside time and space (such as so called ‘noumena’).

Transcendental idealism nevertheless has an important relationship to conceptual idealism, not least from an historical point of view.  Many of the philosophers influenced by Kant, including, for example, Hegel and the Absolute idealists, rejected the notion of the noumenal world.  More importantly, analytic philosophy can be seen as the programme of linguistic analysis hinted at by Kant in the Prolegomena to Any Future Metaphysics[39].  Any analytic philosopher who accepts that the world is necessarily conceivable on the basis that the idea of a reality that is inconceivable is nonsense, is an idealist as I am using the term.

1.4 The Fundamental View of Idealism

Idealism then, comes in many different forms, each with very different commitments.  Is there some idea that underlies these diverse doctrines?  I think that Schopenhauer’s discussion of idealism, though it involves many mistakes, can still point the way to the fundamental view of idealism in general.  The claims of existential dependence in Schopenhauer and Berkeley are the results of arguments, but the fundamental truth of idealism is not supposed to be something that one needs to argue for.  The fundamental view should be something that all idealists can agree on as a starting point, while disagreeing on its implications.  According to Schopenhauer, it is something that should be clear to all once we have turned our reflective attention to it.  For him, this fundamental truth concerns the division into subject and object, on which he says, “it is that form under which alone any representation… is generally possible and conceivable.”[40] But as we have already seen, what counts as subject and object is an issue of dispute amongst idealist.  In any case, it is not the division of subject and object that is most fundamental in Schopenhauer’s reasoning, but the basis on which he puts this suggestion forward: the implied connection between the possible and the conceivable.

The existential dependence between subject and object may be the conclusion of an argument in Schopenhauer’s work, but it would be a mistake to think of him as arguing for the idealistic starting point.  Both the passage quoted above, and the argument based on Berkeley’s Master argument, already contain an idealistic assumption, and one that is not so much argued for, as taken for granted.  That is the assumption that reality is limited by our ability to conceive it, or that if something is in principle inconceivable, then it must be regarded as impossible[41].  It is this assumption that seems to be the fundamental idea of idealism.  So one general way to use the word ‘idealism’ is to use it (as Nagel does[42]) as an adherence to this principle.  Differing claims of dependence, both in respect to the nature of the dependence, and what the dependence holds between, can be seen as deriving from differing notions of conceivability.  Conceptual idealism, for instance, claims that the possible is coextensive with our possible shared public concepts.

Kantian idealism can also be characterised as a conceivability claim, for this is a general consequence of formal dependence.  If the nature of things is not independent of our knowledge, then the world is limited by what judgements we could make.  Note that while this could in some sense be described as an ‘existential’ dependence claim, in that what could exist is said to be dependent on what concepts there could be, this is not an existential dependence in the sense attributed to Berkeleian idealism.  As we have already seen, Kantian philosophy does not have the implausible implication that things are merely representations of our minds.  It is a conceptual dependence between world and understanding.

This concludes our brief review of transcendental idealism and its relation to the fundamental idea of idealism.  Of course, there is more to transcendental idealism than a claim about the limits of the phenomenal world.  Nevertheless, this idea is at the heart of Kant’s transcendental idealism.  It is also this idea that we can discern in Wittgenstein’s Tractatus Logico-Philosophicus, which has been described as Kantian by many commentators.  It is to the work of the young Wittgenstein that we shall now turn to get a more detailed view of the development and influence of idealism in twentieth century analytic philosophy.