Hallucinations for disjunctivists

Jesús Vega-Encabo

Published online: 23 March 2010# Springer Science+Business Media B.V. 2010

Abstract In this paper, I examine the so-called disjunctive views on hallucina-tions. I argue that neither of the options open to the disjunctivist is capable ofaccommodating basic phenomenological facts about hallucinatory experiences andthe explanatory demands behind the classical argument from hallucination. Apositive characterization of the hallucinatory case is not attractive to a disjunctivistonce she is disposed to accept certain commonalities with veridical experiences.Negative disjunctivism glosses the hallucinatory disjunct in terms of indiscrimin-ability. I will argue that this move either renounces to characterize phenomenallythe hallucinatory experience or does not take seriously questions about whyindiscriminability is possible in the phenomenal realm.

Keywords Hallucination . Disjunctivism . Phenomenal character .

Indiscriminability . (Non)-relationality

Disjunctivism and hallucinations

Classical definitions of hallucination underline the perceptual side of thephenomenon and not just the “cognitive” confusion that can derive from it.Hallucination is like a “virtual” perception. It is not a mere delusion; something isphenomenally present for the subject in an hallucinatory experience in such a waythat sometimes the “hallucinator” is liable to be fooled and take it as the basis of amistaken judgment about how things are in the world. It aims to present in a sensory

Phenom Cogn Sci (2010) 9:281–293DOI 10.1007/s11097-010-9155-1

J. Vega-Encabo (*)Department of Linguistics, Logic and Philosophy of Science, Universidad Autónoma de Madrid,Crta. Colmenar km. 15,4, 28049 Madrid, Spaine-mail: Jesus.vega@uam.es

way a rich variety of objects and properties, and it fails. A scientific textbookdefined hallucinations in the following terms:

Any percept-like experience which (a) occurs in the absence of an appropriatestimulus, (b) has the full force or impact of the corresponding actual (real)perception; and (c) is not amenable to direct and voluntary control by theexperiencer (Slade and Bentall 1988, p. 23)

Thus, a hallucination is an experiential event that shares the passive character1

and the “percept-like” nature of perceptual experiences. Both kinds of experienceseem to have in “common” phenomenological features such as the sensory character, theapparent mind independence and existence of the objects and properties presented, theinvoluntariness, or the sense of reality. The absence of an appropriate stimulation isthe way to express why a hallucinatory experience cannot be characterized by aneffective relation to objects and properties that stimulate our brain centers. The definitionindicates also how a hallucination can have the very same effects as a corresponding“real” perception. In some respects, they are so “similar” that some hallucinatoryexperiences could be mistaken for real perceptions. In a sense, both experiences areindiscriminable if the subject is unable to know that she is actually hallucinating.

These facts are gathered by traditional philosophical discussions on the nature ofhallucinations. First, hallucinations are experiences characterized by the way thingslook to the subject. There is something that is what it is like to have the experience.In philosophical jargon, hallucinatory experiences have phenomenal properties orfeatures that characterize what it is like for the subject to have the experience. Inprinciple, we seem entitled to claim that a hallucinatory experience is typed by itsphenomenal character. For S to have the hallucinatory state of a field of green grassis like being experientially given for S a field of green grass, so that the hallucinationis typed by the fact of being an experience as of a field of green grass. Second, thephenomenal character of the hallucination is not fixed by the relations thehallucinator has with objects and properties in the actual environment. Given thatthere is no green grass to which the hallucinator is perceptually related, the“greenness” or the “grass” cannot contribute to the shaping of the phenomenalcharacter of the hallucinatory experience. Third, at least some hallucinations arepresumably indiscriminable from veridical perceptual experiences.2 From thesubject’s point of view, a hallucination and a corresponding perception areindistinguishable in so far as they seem to present to S the “same” appearances.“Indiscriminability” refers to a phenomenological fact about how things look to S.These three notions—phenomenal character, (non-)relationality, and indiscrimin-ability—play a main role in delineating a space for debates on the nature ofhallucinatory experiences and their relation to our successful perceptual experience

1 With this feature, I am just pointing to the idea that the experience is non-voluntary and that its content istaken by the perceiver as passively given. This is not in conflict with the defense of different activetheories of perception.2 In this paper, I focus only on the kind of hallucinations that are indiscriminable from certain perceptionsin such a way that the subject even mistakes them for real perceptions. I am aware that not allhallucinatory experiences are of this kind; many of them are “real” hallucinatory phenomena which thesubject experiences as not perceptually relating him to the world. So in my discussion, I consider“indiscriminability” as a phenomenological fact about some hallucinations, and not just an assumption.

282 J. Vega-Encabo

of the world. The history of our conceptions about perceptual experience is builtaround these three notions.

Phenomenal character, (non-)relationality, and indiscriminability are also at thecore of the classical arguments from hallucination. Many are the forms that thisargument has adopted in philosophical literature.3 I am only interested in thosearguments with metaphysical import that attempt to establish something on thenature of perceptual experience. As other authors,4 I rather like to view the argumentfrom hallucination as a reductio of naïve realism and to distinguish two differentsteps in the structure of the argument. Naïve realism claims that the phenomenalcharacter of a perceptual experience is fixed by the instantiation of a relation ofthe perceiver with objects and properties in the environment. The first step of theargument from hallucination is deemed to establish some conclusion about thehallucinatory case. The second step spreads the conclusion from hallucinations toveridical perceptual experiences. The first step of the argument is difficult tochallenge insofar as it makes an appeal to the apparently uncontroversialphenomenological facts that I have mentioned above: subjective indiscriminabilityand the impossibility of considering that, in the case of hallucinations, thephenomenal character has been shaped by actual relations to mind-independentobjects and properties. The second step is certainly more problematic because theextension from hallucinatory experiences to veridical cases requires some furthersupport. Two main lines of support have been offered: the first one appeals tophenomenological motivations; the second one is derived from considerations aboutthe “sufficient” causal conditions for having a hallucinatory experience.5

Let us focus on the so-called phenomenological argument from hallucination. Inthis version of the argument, the following premise supports the second step: “If anessentially veridical experience and a hallucinatory experience are subjectivelyindiscriminable, then they are experiences typed by the same phenomenalcharacter”.6 This thesis is highly controversial. The antecedent of the conditionalis based on phenomenological considerations; the consequent is an ontological claimabout the kind of experience instantiated both by the hallucination and theperception. This entanglement of phenomenological and metaphysical claims ismisleading. It is certainly not impossible that two experiences be similar in somerespects in such a way that they are subjectively indiscriminable and yet have

3 A first reconstruction of the argument from hallucination can be found in Robinson (1994).4 See for instance Smith (2002) or Martin (2004).5 This appeal to certain metaphysical principles about causality will remain out of discussion in this paper.The core of the dispute about the so-called causal argument from hallucination moves around a thesis of“local supervenience” for perceptual experience. Though prima facie endowed with certain plausibility,the thesis has been challenged by recent embodied and enactive approaches. They provide someinteresting criticisms of brain states as sufficient basis for the supervenience of the perceptual character ofexperiences.6 In the paper, I consider another reading of this assumption. It could be understood as part of anexplanatory argument where the hypothesis that both kinds of experiential states share the samephenomenal character would explain why they are both indiscriminable. So we can consider the truth ofthe following conditional: “If an essentially veridical experience and a hallucinatory experience are typedby the same phenomenal character, then they are subjectively indiscriminable”. The fact of sharing thesame phenomenal character explains why they are indiscriminable. The whole discussion turns aroundwhether being typed by the same phenomenal character is the best explanation available. Disjunctivistswould deny it, as we will see.

Hallucinations for disjunctivists 283

different phenomenal characters (Langsam 1997). If this is true, then it is difficult toaccept a generalization from hallucinatory cases to veridical ones. Let us note thatthis response to the argument from hallucination is indifferent to the characterizationwe offer of hallucinatory experiences as conclusion of the first step of the argument.The strategy consists in accepting that whatever it be the ontological characterizationof a hallucinatory experience, this very characterization is not applicable to veridicalperceptual experiences just because they are subjectively indiscriminable.

So-called disjunctivism7 relies on this strategy to provide a defense of naïve realismagainst the challenge of the argument from hallucination. Disjunctive views are basedon the denial that true statements about how things appear to S are made true by thesame “state of affairs” in hallucinatory cases and veridical ones. There are many waysof building the disjunction. Take the following one as very neutral: “S has anexperience as of a field of green grass if and only if either S has an essentially veridicalexperience of a field of green grass or S has a non-veridical (hallucinatory) experienceof a field of green grass”. By the phrase “essentially veridical,” I understand thefollowing: “A perceptual experience as of a field of green grass is essentially veridicalif and only if, under the perspective P under which a field of green grass appearsphenomenally to S, the experience puts S in contact with a field of green grass”. Thischaracterization is also neutral among many theories of experience. The disjunctivist isalso committed to the thesis that the essential veridicality of the experience reflects theway in which mind-independent objects and properties fix the phenomenal character ofthe experience, that is, by instantiating a relation to these objects and properties. So thedisjunction is pointing to the following: two different kinds of experience can make truestatements about “lookings” or “appearings.” In the left side of the disjunction, the kindof experience is typed by a phenomenal character shaped by the relation of theperceiver with objects and properties in the environment, something that cannot beessential to the alleged phenomenal character of the right disjunct. So what is itessential to the hallucinatory experience?

I characterize disjunctivism as a set of two kinds of principles: substantive andmethodological ones.

Substantive principles

SP1. There is no common factor to veridical and hallucinatory experiences.SP2. Veridical perceptual experiences are essentially relations between a perceiver

and properties and objects in a mind-independent world.

Methodological principles

MP1. Veridical perceptual experiences are explanatorily prior to hallucinatoryexperiences.

MP2. A theory of experience must provide a characterization of hallucinatoryexperiences.8

7 In the last years, disjunctivism has acquired some prominence among the “theories” of perceptualexperience. Two recent compilations are Byrne and Logue (2008) and Haddock and Macpherson (2008).8 Different versions of disjunctivism will add more substantive theses and sometimes also methodologicalones. SP1, for instance, should be qualified, and the methodological principles would need morediscussion.

284 J. Vega-Encabo

SP1 reflects the denial of “common factor” views on experience. SP2expresses realist commitments. MP1 has a very neutral reading: veridicalperceptual experiences are primary even when we attempt to account for thenature of hallucinations. A stronger reading would require an exclusive relationalcharacterization of hallucinations by reference to perceptual experiences. I willcome back to this issue later in my argument. MP2 is not trivial in discussionsabout disjunctivism. Even if one could have thought that a theory of perceptualexperience should take into account both successful and unsuccessful cases, it istrue that once one admits that a hallucinatory experience is ontologicallydifferent from a successful perceptual perception, one could renounce to offer anaccount of hallucinations as belonging to the kinds of mental events that couldnaturally be classified with genuine perceptions. Why should the disjunctivist becommitted to give an account of hallucinatory experiences when her main interestlies in providing a theory of perceptual experience in realist terms?

But don’t we need to offer a characterization of what a hallucination is if we wantto fill adequately the scheme of the disjunction? Consider the following quotation byJonathan Dancy:

In the standard formulation of the account, misleadingly, this is explicitly theway in which the second disjunct is characterized: we characterize it solely bysaying that it is like what it is not. Presumably, however, there may beavailable a more direct characterization of the second disjunct, and in a totallyexplicit version of the theory it would indeed be characterized in that betterway (Dancy 1995, p. 436).

Some disjunctivists contend:

Dancy is wrong to think that the disjunctivist specification is incomplete,that we should supplement the account of experience with a non-relationalgloss of what illusory or hallucinatory experiences are (Martin 2004, p. 46).

So which is the characterization of the character of a hallucinatory experiencefavored by a disjunctivist? Firstly, is such a characterization required by thedisjunctivist project? Secondly, if it is required, which characterization is to beexpected from a disjunctivist? In this paper, I review different versions ofdisjunctivism and conclude than none of them is adequate to account for theexperiential nature of hallucinations.

Positive disjunctivism

Positive disjunctivists9 are committed to give a substantive gloss of the rightdisjunct. They feel the urge to complete the characterization of the disjunctionincluding not just an account of the phenomenal character of perceptions but also anaccount of the experiential event when the perceiver is unsuccessful. For positive

9 The terminology of positive and negative disjunctivism that I will use in this paper is introduced inByrne and Logue (2008).

Hallucinations for disjunctivists 285

disjunctivism, there is a possible characterization of the hallucinatory experience thatis not only given by reference to the veridical disjunct. But once the methodologicalprinciple MP1 is accepted, the disjunctivist is also committed to the explanatorypriority of genuine perceptual experiences. How is it possible to accept bothcommitments?

The positive disjunctivist is sensitive to certain explanatory demands:

1. Intellectually, it seems to be more satisfying to provide an account that could beapplied to all the experiences referred in the disjunction that represents theanalysis of our ascriptions of something appearing to be in a certain way for thesubject. The question is whether there is a possible positive explanation for adisjunctivist that accepts that veridical experiences and hallucinatory ones areontologically different.10

2. At the same time, this sort of disjunctivism is prone to accept that thephenomenology of hallucinatory experiences makes it plausible to think thatthere is something to be like for the subject when she is “hallucinatorily”conscious. In a sense, such a disjunctivist is disposed to reject the idea that thereis a possible “empty” sensory consciousness. The phenomenal character of thehallucinatory experience needs to be explained.

But the disjunctivist is not constrained to accept any particular view on the natureof the hallucinatory experience.11 As I suggested above, this is a consequence ofaccepting the first step in the argument from hallucination no matter how it is built.So, for instance, a disjunctivist could analyze hallucinations in terms of sense-data.Moreover, any other conception in the field is acceptable provided that it iscompatible with disjunctivism, that is, provided that it offers a way to explain howcan perceptions and hallucinations seem to the subject to be phenomenally the same.So a hallucination could be a relation to sense-data, or the mere instantiation ofsensations, or even mental states with intentional content.

Let us assume that the best positive characterization of the hallucinatoryexperience is given in terms of the experience instantiating a representationalcontent. That means that the phenomenal character of a particular hallucination isgiven by the way the subject represents the world as being and not by the actuallayout of the environment. The character of the experience, following an intentionaltheory, is specified by its correctness conditions, that is, by those objects andproperties that would be present if the content were correct. The disjunctivist willthen have a conception where the first part of the disjunction is analyzed in terms ofthe relation with actual objects and properties and the second part in terms of what itwould be correct were those objects and properties actually present. Themetaphysical structure of each phenomenal character is distinct, as expected in thedisjunctivist conception. But this position also entails that there are two verydifferent metaphysical ways to instantiate “phenomenal character” in general: either

10 This kind of explanatory demand is explicit, for instance, in Alston (1999, p. 191).11 Note that the positive disjunctivist needs to offer a view on hallucinations; it is only a radical negativedisjunctivist who would argue against such a “methodological” constraint. The following section wouldhandle mildly epistemic versions of negative disjunctivism which are willing to offer an epistemologicalcharacterization of the hallucinatory disjunct. In a sense, all of them care about the nature of thehallucinatory experience.

286 J. Vega-Encabo

by being in effective phenomenal contact with objects and properties or byentertaining mental states with intentional content, in which case the existence andpresence of objects and properties represented in the content is not required for thestate to be of a particular phenomenal type. Firstly, this position is compatible withSP1 and SP2. Secondly, it explains why things seem the same to the subject both inthe perceptual and the hallucinatory cases (because the very same objects andproperties are presented to the subject, even though in a very different manner) andso a response is given to the argument from hallucination. Nevertheless, it is moredifficult to see how this kind of disjunctivism could comply with the first of themethodological principles. There is no explanatory priority of veridical experiencesbecause in the intentional characterization of a hallucination, nothing depends onhow the phenomenal character of the veridical experience is fixed. If both kinds ofmetaphysical structure are sufficient by themselves to explain how a certainphenomenal character is instantiated, then the priority of the left disjunct needs tobe argued.

Perhaps the priority is preserved just by acknowledging that the left disjunctindicates the “general” structure of the kind of experience that we use to callperceptual: that is, a relational structure that could then vary just in terms of theobjects that are the proper relata of each disjunct. Also, hallucinatory experiences arerelations. So we are committed to posit existing objects and properties that are therelata of the experience and that are not identical to the physical objects (and whichwe can mistake for them). Traditionally, sense-data have been the favorite option inthe philosophical literature. But there are other options: for instance, relations toregions of physical space where the hallucinated object seems to be (Langsam 1997)or relations to “vivid mental images” that appear to the subject in the same way asobjects (Alston 1999, p. 191). Scientific literature is plenty of “imaginistic” views onthe nature of hallucinations.12

But how is the mistake of images with physical objects to be accounted for? Aplausible proposal could be based on some bit of psychological speculation. It couldbe the case that mental images get to be superimposed over our perceptual field. Ifthis happened, it would be open to the subject to mistake these projected images withthe objects they are images of.13 The fact that the subject could accessintrospectively her mental images would also account for the indiscriminabilityfrom a veridical perceptual experience. Images would be the objects that shape thephenomenal character of the experiences in the same sense as the scene perceivedshapes the phenomenal character of a veridical experience.

The question is now whether “intentional contents” or “mental images” are alsopresent in a veridical experience. The disjunctivist could accept that there arecommonalities between hallucinatory and veridical cases without being committedto the claim that they are typed fundamentally in the same way. That which is

12 Some examples are reviewed by Bentall (1990).13 If one accepts the existence of percepts, then the explanation would be in terms of a confusion ofpercepts and images (McGinn 2004). But this route is not open to a disjunctivist that would need then tosay something about the ontological relation between images and percepts because a critic could easilyargue that the very possibility of confusing percepts and mental images is explained by the fact that theyare constituted in the same way (probably as images) and that they contribute in the same manner to anyperceptual experience, veridical or hallucinatory.

Hallucinations for disjunctivists 287

common does not constitute the instantiation of the same ontological kind ofexperience. There are good reasons for accepting that the commonalities exist. One ofthem is the fact that the very same proximal causes seem to be involved in perceptionsand their “causally matching” hallucinations.14 So if mental images, for instance, arealso present in a veridical experience, what is their contribution to the determination ofthe phenomenal character? If, as the naïve realist wants, the phenomenal character isfixed by the objects and properties of the world, the “effects” of these images shouldbe bracketed in the case of a veridical perceptual experience. The disjunctivist couldalso claim that these “vivid mental images” are not present in the veridical case. Whyis it so, if the same causal conditions seem to be sufficient for instantiating them? Is itnot true that the presence of “vivid mental images” is sufficient to determine aphenomenal character in hallucination and is necessitated by the positive conditionthat the veridical and the hallucinatory case share?

Anyway, the main objection against this sort of positive disjunctivism is its lackof explanatory simplicity. Remember that one of the facts to be explained is theindiscriminability of veridical and corresponding hallucinatory experiences. Positivedisjunctivism would claim that there are at least two different ways to sufficientlydetermine the phenomenal character of an experience. True, the psychological kindsof experiences are deemed to be different for the disjunctivist; but in this version, itis also the case that phenomenal characters are metaphysically constituted in verydifferent ways. If it is so, then there does not seem to be any reason to prefer the kindof explanation of phenomenal character provided by the naïve realist.

Moreover, if one accepted that the phenomenal character of the experience couldbe fixed for hallucinatory cases through the instantiation of intentional contents, thedialectical advantages of the naïve realist against the intentionalist will be lost. Infact, the intentionalist seems to be ready to offer a unitary account of the phenomenalcharacter for both terms of the disjunction and thus to account for why we are proneto build the disjunction in the first place.

Epistemic views on hallucinations

Remember Dancy’s quotation in the first section. Disjunctivism seems tocharacterize a hallucination “by saying that it is like what it is not.” This suggeststhat disjunctive views just offer a “negative” characterization of the hallucinatoryevent. The methodological constraint MP1 seems to entail that it does not makesense to provide a characterization of a hallucinatory state in terms of something thatis proper to it. The second disjunct is only specified by reference to the more basiccase of successful perception. What kind of relational property is the one that wouldlink hallucinatory events to veridical perception? Some authors have thought that itis an epistemic property, that property that makes indiscriminable both events. So thefact of the indiscriminability becomes central to an epistemic view on hallucinations.The relevant epistemic property has to do with the possibility to discriminate a “bad”

14 Martin, in a series of deep and thoughtful papers (Martin 2004, 2006), has argued that the disjunctivistmust allow for this kind of commonalities without renouncing to the essential theses of the disjunctiveview. As I indicated before, I need to leave aside this branch of the argument in my discussion.

288 J. Vega-Encabo

case of hallucination from “good” cases of veridical perception. The only “essential”feature of a hallucinatory state is that is just impossible by reflection alone todiscriminate it from a corresponding veridical perception. Someone who ishallucinating cannot introspectively know that she does not perceive.

Martin (2004, 2006) is the most conspicuous defender of this version ofdisjunctivism, usually labeled as “reflective” (Sturgeon 2006). This is his gloss ofthe hallucinatory disjunct:

the disjunctivist really has no option other than to claim that such experienceshave no positive mental characteristics other than their epistemologicalproperties of not being knowably different from some veridical perception(Martin 2004, p. 82).

This is not the only version in town of what could be called an “epistemicconception of hallucination.” William Fish has also provided definitions couched inepistemic terms:

Hallucinations are simply defined as states which have the same kind of effectsas, and are therefore indistinguishable from, certain kind of veridicalperception (Fish 2008, p. 156)

a hallucination is a mental event that, while lacking phenomenal character,produces the same cognitive effects in the hallucinator that a veridicalperception of a certain kind would have produced in a rational subject in thesame overall doxastic setting (Fish 2009, p. 114).

Despite the differences in their respective versions of how to define hallucination,I will discuss Martin’s and Fish’s views together because they attempt to face—though in different ways—traditional objections against the epistemic view.

Both of them try to explain what indiscriminability means. Take for instance Fish’scharacterization in terms of “cognitive effects.” For a hallucination to be indiscriminablefrom a corresponding veridical perception on a particular occasion is necessary andsufficient that it produces the same “cognitive effects” that the corresponding veridicalperception would produce (Fish 2009, pp. 94–95). Which kind of cognitive effects?Typically first-order beliefs and introspective judgments: for instance, the first-order belief that there is in front of me a field of green grass and the second-orderjudgment that I am seeing a field of green grass. In Fish (2008), he appeals to theclassical epistemic theory of experience defended by Armstrong to shape his owndisjunctivist position. For Armstrong, these effects (in particular, higher order beliefsabout our experiences) constitute by themselves the hallucinatory experience. Inappearance, Fish resists this conclusion because this would be a way of “intellectual-izing” the hallucinatory events (Fish 2008, pp. 153–154). But he still argues that theappeal to beliefs is explanatorily sufficient; it explains what the hallucinator says,thinks, or does (p. 153). Besides, beliefs are necessary effects of having a hallucination.No hallucination without these effects.

Obviously, one of the reasons to reject Armstrong’s constitutive view is the factthat unsophisticated animals, incapable of having higher order beliefs, are subject tohallucinatory experiences. Scientific reports are clear on this matter. Fish thinks thatthe same objection cannot be applied to his own point of view because all he needs

Hallucinations for disjunctivists 289

is to appeal to the cognitive effects of the “mental hallucinatory state,” and theseeffects do not need to include “higher-order” beliefs. Hallucinations in animalswithout the capacity to entertain states such as “I believe that I see that p” arecharacterized by other cognitive effects, mental antecedents of the observed behaviorthat helps us to ascribe to them the hallucination in the first place. Worries abouthallucinations in animals also apply to Martin’s epistemic view: the inability of theanimal to have discriminative knowledge of its own states produces the effect that allhallucinatory experiences count as indiscriminable for the animal because this is all ahallucination is: the epistemological negative property of not being able to knowintrospectively that it is not a veridical experience. Both kind of worries—and I willnot enter here into the responses that the defenders of the epistemic views haveprovided against them—are grounded in the very same intuition: a hallucinationcannot consist in an epistemic constraint that is impossible for an animal to satisfy.Moreover, in Fish’s view, it will be impossible that my dog and I could have thesame kind of hallucinatory experience just because the cognitive effects thatindividuate the hallucination are necessarily not the same. In fact, the way Fishintroduces a clause to relativize hallucinations to “doxastic settings” makes it alsodifficult to say which conditions would individuate hallucinatory states. It suffices aset of common effects that a veridical perception would have produced. The questionis that we have no criterion to sort out this set of common effects except thesupposed hallucinatory state itself.

Fish’s view is close to some versions of functionalism about mental states (Siegel2008). But this means that there could be a possible mental state whose causes andcognitive effects would be those of a corresponding “veridical perception” yetlacking any “sensory” character. For Fish, it would be taken as a hallucination. Sothe question is that for this kind of disjunctivism, there is nothing intrinsically“experiential” in a hallucinatory state. It is not just that a hallucinatory state is nottyped by a phenomenal character that could be shared with a corresponding veridicalperception, but also that it does not have any phenomenal character at all. That iswhat makes Fish’s disjunctivism so unintuitive. It rejects the alleged uncontroversialfact that we mentioned at the beginning, the phenomenal character of a hallucinatoryexperience. We are not just certainly wrong each time that we think that we areperceptually experiencing a field of green grass when in fact we are having ahallucination, but we are also deeply wrong when we think to be having an“experience” in this case with a certain “phenomenal character”.15

At this point, the disjunctivist is not placed in a comfortable position. First, one ofthe motivations for disjunctivism is that it “accommodates” the phenomenology ofour perceptual experience. This “phenomenal motivation” is just applied to the caseof veridical perception. No reliance on phenomenology when we deal withhallucinatory experiences. They necessarily fool us about their very nature.16 Inthe case of perception, phenomenology seems to reveal us the real phenomenal

15 If there is something that it is like for the subject to be in that state, it is certainly not “experiential,” itwould be more like having a certain belief (see Fish 2009, p. 98, ft. 19).16 Austin’s contention does not apply here. One can accept that only judgments are true or false and yetclaim for an explanation of why it is the experience that leads me to accept a false judgment. It is thebearing of experience on belief that is here at stake. And in this particular case, it is the bearing ofexperience on introspective judgments that matters.

290 J. Vega-Encabo

character of the experience. As I suggested before, one of the main issues in thediscussion about perceptual experience is whether and to what extent phenomenol-ogy can be used as guide to the metaphysics of experience. Disjunctivism is a viewthat tells us that we should rely on phenomenology just in perceptual cases, not inother cases, even if they are indiscriminable from the first.

In hallucinating, we are wrong not only about how the world is but also abouthow the world seems to be or appear to us. Maybe it is just the hallucinatorycondition that makes us liable to this deep confusion in our thoughts andintrospective capacities. So it is very surprising that disjunctivists do not view thehallucinatory situation as deeply irrational. On the contrary, Fish insists that a certaincondition of rationality is required because otherwise, it would be very difficult toidentify the very same effects that would be produced in the veridical case (the“right” effects). This is needed to exclude cases where a hallucinator thinks to seedragons when she is “seeing” flushing water in a toilet bowl. This would be an“anomalous” belief formation, a failure of rationality. The relevant effects are thosethat would have been produced had the subject been rational. So if there is a “failureof rationality” in hallucinatory moments, this must be of a very different kind fromthe failure we recognize in the clear delusive situation of believing to see dragons influshing water. Those philosophers eager to reject disjunctivism claim that thisdifference in kind is explained by the experiential character of the hallucination,meaning that the effects, in one case, are grounded in the experience (even if thesubject is not much “justified” in holding her first-order belief and her second-orderbelief that she sees) and in the other case are not so grounded in the experience (evenif they are provoked in a sense by it).17

So problems with disjunctivism have mainly to do with the role that “experience”plays in grounding introspective judgments. For Armstrong’s view, this is not a greatproblem because the experience itself is seen as constituted by beliefs or dispositionsto belief. But Fish’s disjunctivism needs to distinguish the mental event thatproduces the effects and the effects themselves. These effects are necessary; bydefinition, no hallucination without the “right” kind of effects. So the disjunctivisthas to argue that it is impossible to be in a hallucinatory mental state when we do notnotice our experiences (and form the corresponding beliefs). Inattention could be oneof the causes for not noticing that one is having a so-called hallucinatory experience(Fish 2009, p. 100). Let’s grant that. But consider the following situation: the effectsare produced later, when the subject remembers that he had an “experiential” eventthat he would take as a veridical perception. A first question is: if there is“something” hallucinatory, when did it take place? Did hallucination take place later,when the effects were produced? But a second question is more pressing: which isthe ground of the subject’s belief? Is it not the previous mental state that heremembers to have entertained? I take it that it is more plausible to think that it is theremembered state and not the remembering itself that grounds the belief.18 So theremust be the “presence” of some features of the state which the subject hasentertained without the corresponding effects at the previous moment that grounds

17 On the nature of delusions and the role played by “anomalous experiences” in generating delusivebeliefs, the paper by Maher (1999) is very helpful.18 This would require more argument than I am capable of in this paper.

Hallucinations for disjunctivists 291

her judgment. The anti-disjunctivist claims that these are “sensory” features even ifthey are not necessarily shared by the veridical experience.

Hallucinations that are recognized as “hallucinatory” by the subject would alsorequire some attention. In a sense, a hallucination that we know not to be a veridicalexperience is not indiscriminable from the corresponding perception (followingMartin’s test). But I claim that it is still possible that the hallucinating subject knowsthat it is not veridical without losing the characteristic “felt reality” that accompanieshallucinatory events in general. The doxastic setting would not prevent thehallucinator from “experiencing” with “reality” the scene. The anti-disjunctivistwould say that in these cases, the conscious shaping of the experience would notneed to change even if the subject knows that it is a hallucination. A possibleresponse could be to acknowledge that the hallucinator is then disposed to make thecorresponding introspective judgments even if “other” considerations (which ones?)would incline him to think that he does not perceive. There is an important questionthat remains open: we don’t know very well what it means that what isphenomenologically given involves a feature that we would introspectivelyrecognize as a “sense of reality” and, worse, that we would introspectively recognizeto be absent in the case of hallucinatory experiences.

Conclusion

I began by remembering that traditional accounts of hallucinatory experiencesattempt to bring together three apparently non-controversial facts about them:phenomenal character, non-relationality, and indiscriminability. This last one is thecore of the phenomenological argument from hallucination. For the proponents ofthe argument, indiscriminability is the ground to posit a shared phenomenalcharacter for veridical perceptions and matching hallucinations. The best way toexplain indiscriminability is to assume that they share phenomenal character. Theargument hides an inference to the best explanation. The whole debate betweendisjunctivists and non-disjunctivists concern the explanatory demands that one isdisposed to accept. Maybe the disjunctivist is right in claiming that indiscrimin-ability as such is not enough to support ontological claims about the phenomenalcharacter of hallucinatory experiences. But at the same time, disjunctivists seemeither to reject such explanatory demands or to suggest that it suffices to appeal tothe indiscriminability property. There is nothing in the way things appear to S that isboth characteristic of the hallucinatory state and explanatory of the indiscriminabilityproperty. In fact, for some disjunctivists, it is only apparent that hallucinations havephenomenal character. Moreover, it is not just any notion of indiscriminability thatdoes the work: disjunctivist’s notion needs to be “asymmetrical” as it is shown byMartin’s characterization in terms of not being able to know that one is not having averidical experience. But why should we accept asymmetry in the first place?Indiscriminability can also be regarded as symmetrical and some reasons are neededto exclude that, when we are talking about experiential states, it is the symmetricalnotion that is involved.

In any case, the explanatory demands are yet in place: why are hallucinations andcorresponding perceptions indiscriminable for S? In Fish’s terms, why do they have

292 J. Vega-Encabo

the same “right” kind of effects? In Martin’s terms, why does the state have thenegative epistemic property? It does not seem enough to respond that it is just adefinitional issue and that the explanatory requirement is misguided. It would be likeasking why bachelors are unmarried (Fish 2009, p. 114). This is, again, not to haveunderstood the challenge posed by the argument from hallucination where theexplanatory demands are not merely analytical. At least, to our common sense, it isplausible to offer an explanation in terms of the way things look. If it is so, then theoptions are two: either to claim for a disjunctivist positive elucidation of the rightdisjunct (a path that, as we have seen, is not without problems) or to rejectdisjunctivism.

Acknowledgments I would like to thank Fernando Broncano, Diego Lawler, Juan González, and twoanonymous referees for their comments and suggestions. This research has been funded by a grant of theSpanish Ministry of Science and Innovation (Reference: HUM2006-03221).

References

Alston, W. (1999). Back to the theory of appearing. Philosophical Perspectives, 13(Epistemology), 181–203.

Bentall, R. P. (1990). The illusion of reality: A review and integration of psychological research onhallucinations. Psychological Bulletin, 107, 82–95.

Byrne, A., & Logue, H. (2008). Introduction. In A. Byrne & H. Logue (Eds.), Disjunctivism.Contemporary readings. Cambridge: MIT.

Dancy, J. (1995). Arguments from illusion. Philosophical Quarterly, 45, 421–438.Fish, W. (2008). Disjunctivism, indistinguishability, and the nature of hallucination. In A. Haddock & F.

Macpherson (Eds.), Disjunctivism: Perception, action, knowledge (pp. 144–167). Oxford: OxfordUniversity Press.

Fish, W. (2009). Perception, hallucination, and illusion. Oxford: Oxford University Press.Haddock, A., & Macpherson, F. (Eds.). (2008). Disjunctivism: Perception, action, knowledge. Oxford:

Oxford University Press.Langsam, H. (1997). The theory of appearing defended. Philosophical Studies, 87, 33–59.Maher, B. (1999). Anomalous experience in everyday life: Its significance for psychopathology. The

Monist, 82(issue 4):547–570.Martin, M. G. F. (2004). The limits of self-awareness. Philosophical Studies, 120, 37–89.Martin, M. G. F. (2006). On being alienated. In T. Gendler & J. Hawthorne (Eds.), Perceptual experience

(pp. 354–410). Oxford: Oxford University Press.McGinn, B. (2004). Mindsight. Cambridge: Harvard University Press.Robinson, H. (1994). Perception. London: Routledge.Siegel, S. (2008). The epistemic conception of hallucination. In A. Haddock & F. Macpherson (Eds.),

Disjunctivism: Perception, action, knowledge. Oxford: Oxford University Press.Slade, P. D., & Bentall, R. P. (1988). Sensory deception. A scientific analysis of hallucination. Baltimore:

The Johns Hopkins University Press.Smith, A. D. (2002). The problem of perception. Cambridge: Harvard University Press.Sturgeon, S. (2006). Reflective disjunctivism. Proceedings of the Aristotelian Society, Supplementary

Volume, 80, 185–216.

Hallucinations for disjunctivists 293