CAN INDISCRIMINABILITY DEFINE HALLUCINATIONS? Disjunctivism, hallucinations and indiscriminability

When it comes to a mental characterisation of the hallucinatory experience, nothing more

can be said than the relational and epistemological claim that it is indiscriminable from the

perception. M.G.F. Martin 2004

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Introduction

Let's suppose that I'm veridically perceiving a mug on my desk. We are facing two different

constraints: we want to say that I am truly perceiving a real mug external to me (and not an image of it,

which would start an infinite vicious circle) and at the same time we want to say that it is well possible

that, in other circumstances, I may also hallucinate this very mug. So the following question arises: are

perceptions and hallucinations of a same kind? But if they are, then how can I ever be sure I am truly

perceiving something?

This kind of reasoning is one of several that lead M.G.F. Martin to commit to disjunctivism about

perception, namely stating that either I'm veridically perceiving something, or I'm hallucinating it,

knowing that both events are part of two radically different kinds. This way of thinking allows to

escape scepticism about the external world and therefore to embrace naive realism (that is to say that

when I'm veridically perceiving, I'm truly perceiving the external world). However, what we are left

with concerning the definition of hallucination, is only negative: when one is hallucinating a mug, it

seems that there is a mug, even though there isn't one. What defines hallucinations is that they are

indiscriminable from perceptions. So a question shall be: is such a negative definition of hallucination

by the use of the concept of indiscriminability possible?

My main assumption will be that disjunctivism is the right direction regarding perception if one

wants to escape scepticism; thus, this essay will not try to be a defense of disjunctivism. On the other

hand, the essay shall question and analyse the negative notion of hallucination offered by Martin. I will

pay a particular attention to the notion of indiscriminability.

With regard to the analysis of indiscriminability, I will firstly review Martin's account of hallucinations

in relation with his commitment to disjunctivism. In a second part, I will give a review of the debate

around Martin's notion of indiscriminability and the questions which it raises and, what is more, I will

propose a general problem concerning it. Finally, I will analyse and advocate the possibility of a

minimal, yet positive notion of hallucinations in disjunctivism following in this Fish (2008).

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I. Martin's disjunctivism and hallucinations

(A) Perceptions, hallucinations and disjunctivism

Let's imagine I'm looking at a mug on my desk. As noted already, common sense imposes us two

constraints when it comes to the question of perception: on the one hand, the idea that it is a real

external mug that I'm perceiving and on the other hand the idea that, in other circumstances, I could

hallucinate a mug on my desk. The first idea is a naive realist claim about perception, namely that

perceiving something is a real connexion to the external world. The second idea is just the necessary

acknowledgment that, despite naive realism, hallucinations do happen. Following this very idea, it had

been claimed that it can never be certain that I'm veridically perceiving something (scepticism) and

thus that naive realism is false.

However this sceptic claim can only be made from the assumption that common sense leads us to think

of perception and hallucination as sharing a fundamental kind: the assumption that two

indistinguishable things are two similar things in kind. Perception and hallucination are

indiscriminable, consequently they share some similar phenomenal properties and therefore we can

never be sure we are not hallucinating. Which means that a common kind claim is inconsistent with

the idea that naive realist is the right conception about perception. Therefore to provide arguments

against a common kind view will enable one to hold the naive realist claim.

A first step in this direction would be to reject the common kind assumption: in other words, to

argue two things are indiscriminable doesn't entail that they are phenomenally similar. It seems to me

that this assumption is more legitimate than the last one. Indeed being able to discriminate between two

things clearly doesn't entail that these things are of the same kind, they could be very different, but due

to some limits of my epistemic powers, I could fail to distinguish them. This line of thinking is known

as disjunctivism about perception. Another way to put it is that either I'm veridically perceiving

something or I'm having an hallucination of it, both things are phenomenally different.

But now, saying that hallucination and perception are different kinds of things, what is left to be said

about hallucination, except that it is not perception? Is disjunctivism able to provide an account of

hallucination?

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(B) Martin's answer: a negative epistemic conception of hallucination

Before that, one shall first decide of what kind of hallucinations we want to talk about. Martin

chose as a paradigmatic case for hallucination, perfect hallucinations (Martin 2004: 47), causally

matching hallucinations (Martin 2004: 71), hallucinations with matching proximate causes (Spiegel

2004: 92). Rightfully he doesn't want to deny the possibility of this kind of hallucinations. Following

Martin we will refer to such hallucinations as perfect hallucinations.

This particular focus on perfect hallucination is not at all a trivial matter as it gives a limiting case for

the disjunctivist to position himself against. If we consider the perception of a mug and the perfect

hallucination of a mug, it's going to be more difficult to hold the position that from this doesn't follow

that perception and hallucination have something in common in kind. Yet this is the very purpose of

some disjunctivists among which Martin stands.

In The limits of the self-Awareness (2004) Martin first gives arguments for endorsing

disjunctivism about perception in general. One motive for endorsing disjunctivism is to commit to

naive realism1, the thesis that states that perceptions are perceptions of mind-independent reality (this

thesis is sustained by common-sense) that are part of the experience and that and no experience of

fundamentally the same kind could have occurred without these real objects. In order to commit to

naive realism one of the two following assumptions, according to Martin, should be abandoned:

Experiential Naturalism (our sense experiences are subject to the causal order therefore causally

matching hallucinations are possible) and The Common Kind Assumption (the mental event when one

is perceiving could happen if one isn't perceiving anything as perception and hallucination are of a

common kind). His argument follows from the blatant inconsistency between the naive realist thesis

and the common kind assumption. Indeed as we have noted it already, if there is no difference in kind

in hallucination and perception except for the presence or not of the object of perception, then how can

I be sure that I'm perceiving and not hallucinating something? If we want to hold both naive realism

and experiential naturalism, then the common kind assumption needs to be abandoned and rejected.

One should commit to disjunctivism.

The second motive for disjunctivism given by Martin is more powerful (for one may not want

to commit to naive realism). Let's suppose that because perception and hallucination are not

discriminable we are entitled to say that they are phenomenally similar. Then the reverse would be also

1 The prime reason for endorsing disjunctivism is to block the rejection of a view of perception I'll label as Naive Realism (2004: 38)

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true, that is to say, if perception and hallucination were not similar we would be able to tell them apart.

Yet this is not the case, as not being able to discriminate between them is what seems to define

hallucination. To argue for the opposite would be, according to Martin, commit to some epistemic

immodesty. So if one commits to epistemic modesty (and following Martin, we all should), then we can

only answer by no the question of whether indiscriminability entails similarity in kind. Not being

discriminable doesn't mean being phenomenally similar or identical.

However Martin raises a problem from his very own reasoning. According to him one may commit

both to experiential naturalism and naive realism. Yet if we hold experiential naturalism then it seems

one shall commit to the view that a perfect hallucination has the same physical causes than a veridical

perception (same cause, same effect). Therefore it seems that there is in fact a common element

between hallucination and perception (the physical causes), the only difference is that, in the case of

perception, there is an extra thing, the object of perception. Disjunctivism is thus threatened by what

Martin calls explanatory redundancy which means that the kind of event which is unique to

perceptual situations will not be explanatory.

However, as Martin puts it, the fact that visual perception depends causally on states of the visual

cortex does not in itself show that the reproduction of those local causes in the absence of objects of

perception would still produce experiences (2004: 55). On the contrary objects are necessary condition

of perceptions, they are constituents of the perception. Yet this is again stating that perception has

something more than hallucination, not that they are phenomenally different. To escape redundancy we

can reformulate the problem and identify something different as being common between perception

and hallucination. First we can argue that although the hallucinatory situation lacks the property in

question (i.e. the mind independent object), one cannot know that the property is absent simply by

reflection on this situation and hence that it at least seems to be present (2004: 66). Arguing that, we

commit to epistemological modesty about what a subject is able to know about his consciousness. As

Martin notes it, seem refers to a subject's evidential position (p66) or an inclination to believe

(p66); seem has an epistemological sense. In other words, the hallucinating situation is

(epistemologically) indiscriminable from a veridical perception. Also, arguing that allows to identify

some common properties between perception and hallucination but without making our claim

redundant. They are introspectible properties (2004: 67), properties which all experiences seem to

have, indiscriminable properties. So here, because the common properties are purely epistemological,

disjunctivism doesn't become redundant (it is not outraced by another explanation).

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In other words, the common-kind theorist would say that perception and hallucination are

indiscriminable in virtue of having the same (specific) robust property (Spiegel 2004: 92) i.e. they

share a common kind. In contrast Martin denies that: perception and hallucination may be

indiscriminable (in the case of causally matching hallucinations) but not in virtue of some robust

property. Indiscriminability is the fundamental kind of hallucination, and this is the only relation that

exists between hallucinations and perceptions. As Spiegel puts it, the disjunctivist and Martin disagree

about the depth and significance of the commonality. For Martin, it goes no deeper than the

indiscriminability property, and it does not constitute the fundamental kind to which both experiences

belong. His strategy thus analyses failure states as hallucinations in terms of success states

(Hawthorne 2006: 146). The fundamental perceptual states are veridical perceptions whereas

hallucinations are described in relations to these states.

There is an important consequence following Martin's strategy:

disjunctivism is now committed to say that, when it comes to hallucination, nothing more can be said that the relational and epistemological claim that is is indiscriminable from the perception. There are

certain mental events whose only positive mental characteristics are negative epistemological ones: they

cannot be told apart by the subject from veridical perceptions.

In brief, if one choses to hold both naive realism and experiential naturalism, one has to commit to a

kind of disjunctivism that gives only a negative epistemological account of hallucinations. In the case

of hallucinations, the naive phenomenal properties are not present but they seem to be present. Yet the

meaning of the seeming occurring in hallucinations is unclear. What does that mean, that the

phenomenal properties seem to be present? Is that more than a linguistic way out from the problem

arising from the apparent incompatibility of naive realism and experiential naturalism? The notion of

indiscriminability is largely problematic as it is mainly empty. We already knew that a perfect

hallucination is indiscriminable from a perception. Are Martin's disjunctivism and his notion of

indiscriminability informative? This notion faces two main challenges: is this notion sufficient and

necessary to account for hallucinations? And more fundamentally, is this notion even philosophically

coherent?

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II. Review of the debate around the account of hallucinations in Martin's disjunctivism : is

indiscriminability (a negative epistemic criterion) a coherent and a sufficient and even a

necessary notion to account for hallucinations ?

Let's now review the main objections that have been raised against the notion of

indiscriminability. This review will enable us to give a more throughout account of the notion as well

as to identify a global problem about it.

Two principal problems or challenges have been raised: the problem of degraded epistemic powers and

the question of the the intransitivity of indiscriminability. As we shall see, these two problems are in

fact linked.

(A) Two objections: degraded epistemic powers and the intransitivity of indiscriminability

According to Susanna Spiegel (2004: 95) as Martin thinks of it, indiscriminability is a notion

defined in terms of judgment. To discriminate two things, she rightfully quotes, is judge them non-

identical (Martin 2004: 62). I myself noted that for Martin seem has an epistemological sense that

refers to a subject's evidential position (Martin 2004: 66). Spiegel concludes that, what's notable is

that Martin's notions of discriminability and indiscriminability seem to be cognitive notions (Spiegel

2004: 95). If this analysis is correct then problems and counter-examples2 arise that threaten the

connexion argued by Martin between indiscriminability and phenomenality. Notably Spiegel (2004)

and Hawthorne (2006) give the counter-example of subjects with degraded epistemic powers (such as

animals). For example a dog can't judge between a white and a cream picket fence. Yet one doesn't

want to say that the dog is hallucinating. The same goes for a human subject whom in some

circumstances (inattention, alcohol...) can't discriminate between these two things. This counter-

example would mean that indiscriminability understood as a cognitive notion is too strong of a

criterion for hallucinations, it is not a necessary criterion of its concept. The indiscriminability would

include both the indiscriminability of veridical perceptions and perfect hallucinations and the

indiscriminability of, for instance, two colours. We shall see later on if these two notions of

indiscriminability are really juxtaposable, or to put it another way, we shall see if Martin's notion of

2 As our main topic in this essay is the notion of indiscriminability we will only review the objections that concern directly the notion in itself (and also for brevity purposes).

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indiscriminability is really a cognitive one.

Hawthorne presents the same criticism (Hawthrone 2006: 164) as Spiegel: a being that did not have the concept of a veridical visual presentation is always unable to know that he

is not having a veridical visual presentation as of a white picket fence (). However, no one wants to be

forced into holding that under such circumstances the relevant being is suffering from a visual illusion,

wherein the veridical perception of white is accompanied by an illusion of cream.

Yet one shall note that for Martin, being indiscriminable doesn't mean being of the same kind. Indeed

that is what Martin's disjunctivism is all about: perfect hallucinations are indiscriminable from veridical

perception and that's what define them. It doesn't follow from that that hallucinations and perception

are of the same kind. However this is this very claim that is questioned by Spiegel and Hawthorne. For

them only a cognitive notion of indiscriminability can exist therefore they argue that one can't make

sense of the claim that two things indiscriminable (some subject can't judge them apart) were

nevertheless discriminable (in the sense that they are different). Now what could it mean to say that

those episodes were nevertheless discriminable? asks Hawthorne. According to him Martin can't claim

both that an hallucination is indiscriminable from a perception and that it is nonetheless of a different

kind (in Hawthorne sense, that is is nonetheless discriminable from it) because he doesn't hold any

positive characterisation of hallucinatory experiences (2006: 165). Here the bone of contention regards

the notion of discriminability and the idea that something can be both discriminable by some subject

and discriminable simpliciter (Hawthorne 2006). According to Hawthorne, it is unclear that this later

notion of indiscriminability (simpliciter) is possible. How should we understand Martin's notion of

indiscriminability if not as a cognitive one?

Before offering a possible answer to this question, let's now look at Hawthorne's second objection

regarding the notion of indiscriminability and more particularly its intransitivity. Indiscriminability is

intransitive as far as, if a is indiscriminable from b and b is indiscriminable from c, it does not follow

from this that a shall be indiscriminable from c. According to Hawthorne what he calls sameness in

look however is not an intransitive notion; if a looks the same as b and b looks the same as c, then a

looks the same as c. Therefore indiscriminability, because intransitive, is inconsistent with sameness

in look which is transitive. And according to Hawthorne, if two things indiscriminable are not

understood as two things looking the same, then indiscriminability is a concept that doesn't make sense.

Two objections against this conclusions are possible: firstly it is not clear that sameness in look is

transitive if we understand by it some kind of cognitive notion. An object always looks this way or

this other way regarding a subject only. It is relative to a subject and to a time. Even if we accept

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Hawthorne's analysis of it as being transitive, one can claim that indiscriminability is not an intransitive

notion because it is not a cognitive notion. So, as we notice it, both the question of the intransitivity of

indiscriminability and the question of degraded epistemic powers arise because of some indeterminacy

concerning the concept of indiscriminability: does epistemic mean cognitive?

(B) Martin's answer: impersonal indiscriminability

Martin answers both of these problems in his 2006 paper by the concept of impersonal

indiscriminability. Although Hawthorne dismissed this solution as being an unabashed relying on the

primitive ideology of impersonal indiscriminability which builds an impenetrable fortress, we shall

analyse this notion especially because I think the problems around this notion ask the most relevant

questions when it comes to Martin's disjunctivism. How does impersonal indiscriminability answer to

both objections?

To understand this notion, one shall stress on the difference between a subject's cognitive response to

their circumstances (Martin 2006: 26) i.e. his inclination to attend and the judgements he is liable to

make (p28) and how he will or will not experience the world to be (our stressing, p28). Therefore,

from saying that John (for e.g.) can't discriminate between a white and a cream picket fence, we are not

committed to saying that his experiences should be the same. Indiscriminability should not entail

sameness of look precisely because indiscriminability is in fact not a cognitive notion concerned with

one's judgement. That both experiences are indiscriminable doesn't entail they are the same. As Martin

puts it (2006: 26): I shall suggest that the disjunctivist needs to stress the connection between phenomenal consciousness

and having a point of view or perspective on the world. The negative epistemological condition when

correctly interpreted will specify not a subject's cognitive response to their circumstances and hence

their knowledge or ignorance of how things are with them but rather their perspective on the world.

One shall also notice, that to discriminate or not to discriminate is most of the time not a question of

judgement or knowledge but more a question of experience. For example, to recognise people faces,

therefore to discriminate between them, is a function that is far different from analysing similarities

between them. In some people suffering from a particular type of agnosia (prosopagnosia) this function

isn't working anymore, and they can only discriminate faces by using analysis (I recognize my friend's

face because he wears some particular glasses, because he has a strange shaped mole, etc.) which we

don't use in normal circumstances.

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The natural thought that visual indiscriminability entails sameness of appearance comes from the idea

that sight is a mode of coming to be aware of a realm independent of it. Martin however claims that

we should not think of introspection in this way, which for Martin, coincides with experience itself and

is not independent of it. If we think of introspection in a mistaken way we will indeed end up accepting

introspection as been able to track down the phenomenal character of one's experience without being

able to justify this super-mechanism.

When talking about 'impersonal indiscriminability' Martin has thus in mind an appeal to an impersonal

talk of inability or incapacity (2006: 29), in such a situation (perfect hallucinations), it is impossible

simpliciter for John to tell apart through introspective reflection from a veridical perception (p29).

Martin's main claim is that to talk of the impersonal indiscriminability (...) It is to talk about the

experiential situation (our emphasis, 2006: 31).

(C) One worry about this notion

Yet one might worry that this kind of notion, 'impersonal indiscriminability', is still difficult to

hold consistently. For as we have just pointed out, it is both an epistemic and experiential notion. In

'impersonal indiscriminability', Martin intends to give an answer to two sort of questions, two kinds of

paradigms: epistemic and phenomenal (experiential). What the history has shown however is that

phenomenology and epistemology don't mix particularly well together. Husserl already confronted to

this problem3: his concept of intentionality was giving an answer to two different paradigms, linguistic

and perceptive. This lead the next generation of phenomenologists to separate both questions, the

phenomenal question on the one hand, the linguistic question on the other hand. I shall argue that

Martin confronts the same problem with his concept of 'impersonal indiscriminability': different

constraints raised from the different paradigms involved. Naive realism imposes constraints from a

phenomenal point of view, while Experiential Naturalism and perfect hallucinations impose

epistemological constraints. Yet it is not clear that both can be united and that the concept forged by

Martin is more than a linguistic way-out of the problem.

Nonetheless I don't intend to reject this concept completely. One shall indeed keep in mind that

Martin tackles only 'perfect hallucinations', a notion, I shall argue, that takes the question of

hallucinations in a highly abstract level. In my mind, an abstract notion as 'impersonal

3 see Fifth Logical Investigations (1973), Ideas Pertaining to a Pure Phenomenology and to a Phenomenological Philosophy - Third Book: Phenomenology and the Foundations of the Sciences (1980)

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indiscriminability' is in fact totally entitled to answer such an abstract question as 'perfect

hallucinations'. Saying otherwise would be misguided and unfair to Martin. Indiscriminability seems to

be the right way to answer the question of perfect hallucinations. 'Impersonal indiscriminability'

however is a difficult notion to hold. How therefore should we tackle indiscriminability? Moreover one

might also ask for a positive account of hallucinations4, is indiscriminability able to do so?

III. Is a positive disjunctivist account of hallucination possible ?

What kind of notion indiscriminability should be?

William Fish's notion of indiscriminability

(A) 'true hallucinations' as the paradigmatic case for hallucinations

William Fish answers both of these worries in his 2008 paper (Disjunctivism,

Inistinguishability, ad the Nature of Hallucination). His first important move away from Martin is to

redefine what is the paradigmatic case for hallucinations, from 'perfect hallucinations' to 'true

hallucinations' (Fish 2008: 145). When one's suffering a true hallucination of a mug, one honestly

believes he is seeing a mug. Fish will not refer to an 'impersonal' notion of indiscriminability however,

he reminds us that indiscriminability (or 'indistinguishability', both notions are equivalent for Fish)

doesn't need to entail sameness in look or even similarity in look. If one takes into account the

discriminatory context5, then it is coherent that one may fail to distinguish between two things which

are intrinsically quite distinct (p147). Of course, this does not prove that hallucinations are not

phenomenally similar to veridical perceptions but at least this proves that we don't have to assume they

do.

(B) Fish's rejection of Experiential Naturalism

A second move away from Martin is for Fish to reject a certain kind of 'Experiential Naturalism'

that Martin had accepted. A same cause, same effect principle is defended for instance by Smith 6.

4 See Dancy 1995. Also see Surgeon: disjunctivism offers no positive story about hallucination at all and takes indiscriminability for granted (2000: 11-12), quoting by Fish (2008: 144).

5 p146: the context under which the discrimination is attempter, that is, the subject's discriminatory capacities an the observation conditions.

6 it is surely not open to serious question that [this principle] does apply with respect to the merely sensory character of conscious states (Smith 2002:202), quoted by Fish p148.

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This principle means that what we have called 'perfect hallucinations' are possible, or in other words,

that 'phenomenally identical' hallucinations are possible (Fish p148). If it is indeed theoretically

possible, according to Fish, it is interesting to question it, for the main motivations for it, are already

appealing to the fact of indistinguishability (hallucinations seem to be states with phenomenal character

similar to perception that originate from the brain) and as we have noted it, from mere

indiscriminability sameness in kind doesn't necessarily follow. Finally Fish appeals to results from

neuroscience which never prove that artificially induced hallucinations were 'phenomenally identical'

to perception. He concludes that a disjunctivist doesn't need to appeal to Experiential Naturalism,

therefore is not limited by a definition of 'perfect hallucinations' (p149): I suggest the disjunctivist need not assume that the theoretical possibility of precise neural replication

alone is enough to establish the possibility in principle of a special kind of phenomenally identical

hallucination.

This will allow Fish to work out a different notion of indiscriminability that will avoid the different

problems we have noticed.

(C) An effect-base notion of indiscriminability

As Martin, Fish doesn't consider indiscriminability as a cognitive act7. Indeed doing so would

imply that there are two things to discriminate and a discriminator making (at least attempting to make)

the discrimination. As Fish puts it, there aren't two mental states experienced in succession, and it is not

clear that a kind of pre-reflective observer (Williamson 1990: 13) is involved when we want to use

indiscriminability to define hallucinations. We don't take an observational stance (his words) towards

our mental states. Hence Fish follows Martin's intuition that the problem lies in a wrong conception of

introspection. Yet Fish goes further than Martin and offer another conception inspired by Sturgeon who

claims that introspection is one type of belief formation8 and that, therefore to say two states are

indistinguishable (...) is to say that they register equivalent in introspection (Sturgeon 2000: 12). In

other words, both states generate equivalent introspective beliefs which explains why the subject thinks

7 See Williamson 1990: 8: a is indiscriminable from b for a subject at a time if and only if at that time the subject is not able to discriminate between a and b, that is, if and only if at that time the subject is not able to activate (...) the relevant kind of knowledge that a and b are distinct. See also Spiegel 2004: 98 for a similar definition

8 introspective beliefs about visual states spring directly from visual states themselves, there is no observer (Sturgeon 2000: 12).

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honestly that he is veridically perceiving9.

Martin develops hence a notion of indiscriminability that is more consistent than Martin, a notion that

is not 'impersonal' but is defined by the beliefs hold by the subject suffering from an hallucination.

However Fish doesn't hold a constitutive claim that those beliefs are hallucinations (see Armstrong

1961) but that they are effects of them. If we therefore stipulate that the appearance of such higher-order beliefs is indicative of sufficient

similarity in effects, and hence indicative of registering equivalently in introspection, then given the

account of indistinguishability developed earlier, this would ground the claim that this mental state is

indistinguishable from that kind of veridical perception. The mental state would thereby qualify as a

hallucination.

This effects-based version (Spiegel's words, see 2008) of indiscriminability accommodates well the

case of degraded or a non-existent epistemic powers. Indeed the only difference is that, in the case of

cat, the effects will not be beliefs but behaviours (p155), for instance the cat will stroke in the air an

non-existent butterfly.

According to Fish this account of indiscriminability is not a negative epistemic criterion (as it

was for Martin) but a positive yet minimal account of hallucinations. And I shall agree with his claim

that a demand for a more substantial characterisation is misguided (p156) for it is an analytical

definition to state that hallucinations (may10) have the same effects as perceptions.

One major move away from Martin is for Fish to abandon one of the paradigms to tackle by

endorsing a kind of anti-realism about hallucinations. Fish rejected both Experiental Naturalism and

realism about the nature of hallucinations: they don't have phenomenal character, they only seem to

have some11. I shall argue from this, a more substantial claim can however be made. Spiegel in her

2008 paper argued that the effects-based notion of indiscriminability can't account for the felt reality

of hallucinations (2008: 215). Yet even if one doesn't need to assume that hallucinations have any

phenomenal character, one can tell stories about hallucinations and how they are felt. One can note

for example that hallucinations and perception don't have the same temporal nor spatial properties. I

can take a mug in my hand and put it to careful scrutiny from all my senses in a long amount of time

whereas most of the time an hallucination is fleeting and ephemeral and can't resist such a careful

scrutiny. To believe I'm hallucinating might hence be very fleeting in most of personal experiences.

9 For beliefs to be equivalent they need to be sufficiently similar, but we can't give a more precise definition for sufficiently as there could be different ways for to it to be sufficient (p152).

10 In the case of resisted hallucinations, the subject undergoing the hallucianation is well aware that is not veridically perceiving. See Fish 2008 and also for stories about such resisted undergoing see Merleau-Ponty 1945.

11 For a radical version of such anti-realism about hallucinations, see Dennett 1991.

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Whether hallucinations have a phenomenal character different from perception (see Merleau-Ponty

1945) or have no phenomenal character, I prefer to leave the question open for it doesn't change the

disjunctivist conclusion. Forgetting such a difference between hallucinations and perceptions might

have been caused by the philosophers' focus on visual hallucinations only. So I shall argue, that from a

minimal account of hallucinations that doesn't assume anything about the phenomenal character of

hallucinations, then stories can be told by phenomenologists. A minimal epistemic definition is not

inconsistent with more throughout phenomenal analysis and comparisons. This leads me to claim that

disjunctivism need not to be only epistemological and the choice is left to the philosophers to come

back to the root of it, phenomenological disjunctivism (see Merleau-Ponty 1945).

Conclusion:

This essay discussed the disjunctivist notion of indiscriminability focusing primarily on the

question of whether indiscriminability can define hallucinations?. In order to answer this question we

followed the debate this notion has created, a debate which helps us stating what indiscriminability can

and cannot be understood as. To the question of whether indiscriminability is a good tool to give an

account of hallucinations, we shall answer positively as long as indiscriminability is neither to be

understood as a cognitive act nor an impersonal notion (both interpretations leading to serious

conceptual difficulties). A minimal yet positive notion of indiscriminability has been advocated by

William Fish, answering most of these difficulties and leading to a relative anti-realism about

hallucinations. As anti-realism about hallucinations doesn't entail that no stories can be told about the

'felt reality' of hallucinations, we shall argue that disjunctivism has found in Fish's indiscriminability a

powerful and subtle epistemic conception of hallucinations. Asking epistemologically for more would

be misguided, yet from a phenomenal point of view, more stories can be told about the difference

between perceptions and hallucinations.

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Bibliography and references:

Armstrong, D. M., 1961, Perception and the Physical World. London: Routledge & K. Paul.

Dancy, J., 1995, Arguments from Illusion, The Philosophical Quarterly, 45: 42138.

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