Alexandre Billon

According to a common philosophical intuition, the deep nature of things is hidden from us, and the world as we know it through perception and science is, just like a dream, shadows, or a computer simulation, somehow shallow and lacking in reality. This “intuition of unreality” clashes with a strong, but perhaps more naive, intuition to the effect that the world as we know it seems perfectly real. Shadows, dreams, or informational structures appear too unreal to be identical to the world as we know it! This clash between the two intuitions forms the basis of the “problem of reality.” In the late nineteenth century psychiatrists encountered patients they referred to as “metaphysician doubters” who constantly questioned the reality of the world. This essay draws on studies of these patients in order to reject, and indeed diagnose, the intuition of unreality and recent metaphysical doctrines drawing on it, such as structuralism, digitalism, and virtual realism.

According to a common philosophical intuition, the deep nature of things is hidden from us, and the world as we know it through perception and science is somehow shallow and lacking in reality. For all we knwo, the intuition goes, we could be living in a cave facing shadows, in a dream or even in a computer simulation, This “intuition of unreality” clashes with a strong, but perhaps more naive, intuition to the effect that the world as we know it seems perfectly real. Shadows, dreams, or informational structures appear too unreal to be identical to the world as we know it! This clash between the two intuitions forms the basis of the "problem of reality." At the turn of the nineteenth century psychiatrists encountered patients they referred to as “metaphysician doubters” who constantly questioned the reality of the world. This essay draws on the study of these patients to reject, and indeed diagnose, the intuition of unreality and recent metaphysical doctrines drawing on it, such as structuralism, digitalism, and virtual realism.

In a previous article on cosmological arguments, I have put forward a few examples of complete infinite and circular explanations, and argued that complete non-wellfounded explanations such as these might explain the present state of the world better than their well-founded theistic counterparts (Billon, 2021). Although my aim was broader, the examples I gave there implied merely causal explanations. In this article, I would like to do three things: • Specify some general informative conditions for complete and incomplete non-wellfounded causal explanations that can be used to assess candidate explanations and to generate new examples of complete non-wellfounded explanations. • Show that these conditions, which concern chains of causal explanations, easily generalize to chains of metaphysical, grounding explanations and even to chains involving other “determination relations” such as supervenience. • Apply these general conditions to the recent debates against the existence of nonwellfounded chains of grounds and show, with a couple of precise examples, that the latter can be complete, and that just like in the case of causal explanations, non-wellfoundedness can in fact be an aset rather than a liability.

In their target article, Kammerer and Frankish (K&F) wonder what forms introspection could take in non-human animals, enhanced humans, artificial intelligences, and aliens. In this short note, I focus on disordered or neurodiverse minds. More specifically, I assess a claim that has often been made more or less implicitly to the effect that, in virtue of their conditions, people with schizophrenia or depersonalization disorder have superior introspective abilities that allow them to discern some important but normally hidden characteristics of our experiences — call this the superintrospectionitis thesis. In the course of my argumentation, I introduce distinctions and questions concerning the nature of the architecture and the function of introspection that might enrich K&F's framework.

Patients suffering from depersonalization complain of feeling detached from their body, their mental states, and actions or even from themselves. In this chapter, I argue that depersonalization consists in the lack of a phenomenal feature that marks my experiences as mine, which is usually called “mineness,” and that the study of depersonalization constitutes a neglected yet incomparable probe to assess empirically the scope, role, and even the nature of mineness. Here is how I will proceed. After describing depersonalization (§2) and arguing that it involves a lack of mineness (§3) I will confront a series of objections (§4). I will then spell out what depersonalization can teach us about the scope of mineness (§5), about its role and psychological function (§6) and even about its nature (§7).

If I see, hear, or touch a sparrow, the sparrow seems real to me. Unlike Bigfoot or Santa Claus, it seems to exist; I will therefore judge that it does indeed exist. The “sense of existence” refers to the kind of awareness that typically grounds such ordinary judgments of existence or “reality.” The sense of existence has been invoked by Humeans, Kantians, Ideologists, and the phenomenological tradition to make substantial philosophical claims. However, it is extremely controversial; its very existence has been called into question. This paper aims to clarify the nature and reality of the sense of existence by studying a psychiatric condition in which the sense appears to be disrupted: depersonalization disorder (DPD).

Le sentiment du sublime est une expérience de la nature qui nous fait prendre conscience de la place paradoxale que nous occupons dans le cosmos et provoque par ce biais un plaisir ambivalent. Selon la théorie classique, kantienne, cette expérience proviendrait d’une sorte de combat de catch mental, dont on perdrait les premiers rounds en laissant la nature déborder nos sens, mais que l’on finirait par remporter grâce à la puissance de notre raison et de notre liberté. On n’aurait d’expérience de sublime, toujours selon cette théorie, que face à des objets naturels dignes d’être (mentalement) combattus, des choses immenses ou terriblement puissantes comme le ciel étoilé, les montagnes ou les ouragans. Je prétends dans cet article que la théorie classique dépend d’une conception de la nature que nous ne pouvons pas trouver crédible aujourd’hui (une conception, très sommairement, agonistique et anthropocentrée) et qui la discrédite. Corrélativement, elle se trompe quant à l’objet du sublime, qui peut être une chose relativement petite comme un arbre ou même, peut-être, une brindille oscillant dans le vent. Je propose une théorie alternative du sublime qui repose sur une forme de décentrement empathique dans la nature, fût-elle indifférente et sauvage, plutôt que sur un combat mental contre elle.

Many philosophers regard the persistence of philosophical disputes as symptomatic of overly ambitious, ill-founded intellectual projects. There are indeed strong reasons to believe that persistent disputes in philosophy (and more generally in the discourse at large) are pointless. We call this the pessimistic view of the nature of philosophical disputes. In order to respond to the pessimistic view, we articulate the supporting reasons and provide a precise formulation in terms of the idea that the best explanation of persistent disputes entails that they are pointless. We then show how to answer the pessimistic argument. Taking a well-known mathematical controversy as our paradigm example, we argue that some persistent disputes reflect substantive disagreements at the “meta-analytic” level, i.e., disagreements about the best way, among quite different candidates, to understand the topic at issue, and the best associated cluster of analytic truths one should accept concerning it. Moreover, our concrete example shows that such meta-analytic disagreements can in principle be settled and yield a genuine theoretical (as opposed to merely pragmatic) breakthrough. We conclude optimistically that persistent disputes can be an important means of fostering epistemic progress.

Depersonalization consists in a deep modification of the way things appear to a subject, leading him to feel estranged from his body, his actions, his thoughts, and his mind, and even from himself. Even though, when it was discovered at the end of the 19th century, this psychiatric condition was widely used to probe certain aspects of bodily awareness, and more specifically the sense of bodily ownership (SBO), it has been strangely neglected in contemporary debates. In this chapter, I argue that because of three specific features, depersonalization raises some important challenges for current theories of the SBO. The first feature — call it “generality” — is that depersonalization does not only affect the sense of bodily ownership but also, typically, the sense of ``mental ownership’’ (SMO), the sense of agency or ``action ownership’’ (SOA), and the subject’s core sense of herself (CSS), that is, her awareness of herself as an I. The second feature is that except for the symptoms of depersonalization, depersonalized patients are hard to distinguish, psychologically, from normal subjects. This makes it hard to find psychological features that might explain their condition. The last feature, call it “fundamentality” is that the psychological features that do seem abnormal among depersonalized patients seem more likely to be explained by depersonalization than to explain it. These three features raise three challenges — the centrality challenge, the dissociation challenge, and the grounding challenge. Taken together, I will argue, these challenges suggest that the SBO depends on a form of phenomenal “mineness” that would mark my mental states as mine and that cannot be accounted for in sensorimotor, cognitive, or even affective terms. A phenomenal mineness that indeed seems to be psychologically primitive, and only accountable in neurophysiological terms.

Consider an infinite series whose items are each explained by their immediate successor. Does such an infinite explanation explain the whole series or does it leave something to be explained? Hume arguably claimed that it does fully explain the whole series. Leibniz, however, designed a very telling objection against this claim, an objection involving an infinite series of book copies. In this paper, I argue that the Humean claim can, in certain cases, be saved from the Leibnizian “infinite book copies” objection, and that this provides an interesting way to defuse some cosmological arguments for the existence of God and to give a non-theistic but complete explanation of the Universe. In the course of my argumentation, I also show that circular explanations can be “self-explanatory” as well: explaining two items by each other can explain the couple of items tout court.

According to what we will call subjectivity theories of consciousness, there is a constitutive connection between phenomenal consciousness and subjectivity: there is something it is like for a subject to have mental state M only if M is characterized by a certain mine-ness or for-me-ness. Such theories appear to face certain psychopathological counterexamples: patients appear to report conscious experiences that lack this subjective element. A subsidiary goal of this chapter is to articulate with greater precision both subjectivity theories and the psychopathological challenge they face. The chapter’s central goal is to present two new approaches to defending subjectivity theories in the face of this challenge. What distinguishes these two approaches is that they go to great lengths to interpret patients’ reports at face value – greater length, at any rate, than more widespread approaches in the extant literature.

Most paradoxes of self-reference have a dual or ‘hypodox’. The Liar paradox (Lr = ‘Lr is false’) has the Truth-Teller (Tt = ‘Tt is true’). Russell’s paradox, which involves the set of sets that are not self-membered, has a dual involving the set of sets which are self-membered, etc. It is widely believed that these duals are not paradoxical or at least not as paradoxical as the paradoxes of which they are duals. In this paper, I argue that some paradox’s duals or hypodoxes are as paradoxical as the paradoxes of which they are duals, and that they raise neglected and interestingly different problems. I first focus on Richard’s paradox (arguably the simplest case of a paradoxical dual), showing both that its dual is as paradoxical as Richard’s paradox itself, and that the classical, Richard-Poincaré solution to the latter does not generalize to the former in any obvious way. I then argue that my argument applies mutatis mutandis to other paradoxes of self-reference as well, the dual of the Liar (the Truth-Teller) proving paradoxical.

Basic self-awareness is the kind of self-awareness reflected in our standard use of the first-person. Patients suffering from severe forms of depersonalization often feel reluctant to use the first-person and can even, in delusional cases, avoid it altogether, systematically referring to themselves in the third-person. Even though it has been neglected since then, depersonalization has been extensively studied, more than a century ago, and used as probe for understanding the nature and the causal mechanisms of basic self-awareness. In this paper, I argue that depersonalized patients indeed have an impaired basic self-awareness, and that their study allows us both to favor one specific theory of basic self-awareness and to understand what is wrong with its rivals. According to the favored theory, which I call Cartesian, we are basically self-aware in virtue of being acquainted with ourselves through introspection.

Depersonalization is a pathological condition consisting in a deep modification of the way things appear to a subject, leading him to feel estranged from his body, his actions, his thoughts, his mind and even from himself. In this article, I argue that the study of depersonalization raises three challenges for recent theories of the sense of bodily ownership. These challenges—which I call the centrality challenge, the dissociation challenge and the grounding challenge— thwart most of these theories and suggest that the sense of bodily ownership hinges on a phenomenal mark of mineness that can not be accounted for in terms of our sensory, interoceptive, agentive, cognitive or affective dispositions and that is psychologically primitive. In short: that mineness is first.

Cet article aborde le problème de la justification des attributions d'expérience à autrui (problem of other minds). Je compare ce problème à d'autres problèmes sceptiques contemporains dus à Nelson Goodman et Saoül Kripke et je montre qu'il constitue un défi plus pressant et auquel il est plus difficile de répondre de manière modeste. Je propose une solution radicale à ce problème, qui repose sur l'idée, avérée empiriquement, selon laquelle nous disposons de deux formes d'empathie distinctes pour accéder à autrui. Très sommairement, lorsque je m'interroge sur autrui de manière objective et désengagée, je ne peux accéder à son esprit que par empathie cognitive, et le problème des autres esprits est alors insoluble. Lorsqu'autrui m'est présenté en personne, par contre, j'accède à son esprit par une forme d'empathie affective et le problème de l'esprit autrui est alors littéralement dépourvu de sens.

emantic pathologies of self-reference include the Liar (‘this sentence is false’), the Truth-Teller (‘this sentence is true’) and the Open Pair (‘the neighbouring sentence is false’ ‘the neighbouring sentence is false’). Although they seem like perfectly meaningful declarative sentences, truth value assignment to their uses seems either inconsistent (the Liar) or arbitrary (the Truth-Teller and the Open-Pair). These pathologies thus call for a resolution. I propose such a resolution in terms of relative-truth: the truth value of a pathological sentence use varies with the context of its assessment. It always has a determinate truth value, but this truth value is relative to the context of its assessment. I start by considering a fairly esoteric pathology: the Truth-Teller, that is, sentences which assert nothing but their own truth. I make the case that truth value of a given truth-teller use must in general depend on the context of its assessment, and that one can indeed change its truth value at will. I then show how the notion of assessment-sensitive truth can help us provide solutions to other semantic paradoxes such as the Liar and the Open Pair and that those solutions are immune to revenge problems. I conclude by situating my proposal among the main approaches to the semantic paradoxes, and by drawing a very broad moral about pathological self-reference and intentionality.

Ttler=‘Ttler is true’ says of itself that it is true. It is a truth-teller. I argue that we have equally telling arguments (i) to the effect that all truth-tellers must have the same truth-value (ii) and the effect that truth-tellers differ in truth-value. This is what I call the Truth-Tellers paradox. This paradox stems from the fact that the truth-value of a truth-teller like Ttler should be determined by the fact that it says of itself that it is true (which entails (i)) but that it cannot be determined by that fact (as witnessed by (ii)). The Truth-Tellers paradox resem- bles the classical semantic paradoxes like the Liar. In both cases, a form of self-reference allows us to derive a contradiction from oth- erwise plausible semantic and logical principles. Furthermore the Truth-Tellers paradox can be formulated without using sentences which are in an intuitive sense ungrounded, it thus severs the link, almost universally taken for granted, between the semantic para- doxes and ungroundedness. Finally, some classical solutions to the Liar do not generalize to the Truth-Tellers paradox.

Descartes was certain that he was thinking and he was accordingly certain that he existed. Like Descartes, we seem to be more certain of our thoughts and our existence than of anything else. What is less clear is the reason why we are thus certain. Philosophers throughout history have provided different interpretations of the cogito, disagreeing both on the kind of thoughts it characterizes and on the reasons for its cogency. According to what we may call the empiricist interpretation of the cogito, I can only claim to be certain of having experiences, and this certainty, as well as that of my own existence, stems from their phenomenal and subjective character. According to rationalist interpretations, on the other hand, I am certain of having some self-reflexive propositional attitudes, and this certainty derives from their rational features. Psychiatric patients suffering from acute forms of depersonalization or of the Cotard syndrome often doubt that they think and exist, and might even believe that they don't. I argue that their study allows us to favor the empiricist interpretation of the cogito

Basic self-awareness is the kind of self-awareness reflected in our standard use of the first-person. Patients suffering from severe forms of depersonalization often feel reluctant to use the first-person and can even, in delusional cases, avoid it altogether, systematically referring to themselves in the third-person. Even though it has been neglected since then, depersonalization has been extensively studied, more than a century ago, and used as probe for understanding the nature and the causal mechanisms of basic self-awareness. In this paper, I argue that depersonalized patients indeed have an impaired basic self-awareness, and that their study allows us both to favor one specific theory of basic self-awareness and to understand what is wrong with its rivals. According to the favored theory, which I call Cartesian, we are basically self-aware in virtue of being acquainted with ourselves through introspection.

Motivationally unconscious (M-unconscious) states are unconscious states that can directly motivate a subject’s behavior and whose unconscious character typically results from a form of repression. The basic argument for M-unconscious states claims that they provide the best explanation to some seemingly non rational behaviors, like akrasia, impulsivity or apparent self-deception. This basic argument has been challenged on theoretical, empirical and conceptual grounds. Drawing on recent works on apparent self-deception and on the ‘cognitive unconscious’ I assess those objections. I argue that (i) even if there is a good theoretical argument for its existence, (ii) most empirical vindications of the M-unconscious miss their target. (iii) As for the conceptual objections, they compel us to modify the classical picture of the M-unconscious. I conclude that M-unconscious states and processes must be affective states and processes that the subject really feels and experiences —and which are in this sense conscious— even though they are not, or not well, cognitively accessible to him. Dual process psychology and the literature on cold-hot empathy gaps partly support the existence of such M-unconscious states.

There is a long tradition in philosophy of blaming passions for our unhappiness. If only we were more rational, it is claimed, we would live happier lives. I argue that such optimism is misguided and that, paradoxically, people with desires, like us, cannot be both happy and rational. More precisely, if someone rational has desires he will not be fully happy, and if he has some desires that are rational and – in a yet-to-be-specified sense – demanding, he will be frankly unhappy. Call this claim Rational Pessimism. The argument for Rational Pessimism can be considered as a variation on a Schopenhauerian argument that bluntly claims that, because desires involve lack and suffering, desiring souls like us cannot be happy. I argue that, even if Schopenhauer’s argument escapes most attacks that have been targeted against it, it faces decisive empirical objections. I argue that Schopenhauer’s argument can, however, be rescued if it is assumed that we are rational.

We examine how Frege’s contrast between identity judgments of the forms “a=a” vs. “a=b” would fare in the special case where ‘a’ and ‘b’ are complex mental representations, and ‘a’ stands for an introspected ‘I’-thought. We first argue that the Fregean treatment of I-thoughts entails that they are what we call “one-shot thoughts”: they can only be thought once. This has the surprising consequence that no instance of the “a=a” form of judgment in this specific case comes out true, let alone a priori true. This further reinforces Glezakos’s objections against the set-up of Frege’s puzzle, while also raising what we think is an acute problem for Fregeans, insofar as I-thought (and indexical thinking more generally), understood in their way, turns out to be incompatible with some basic features of rationality.

Patients suffering from the Cotard syndrome can deny being alive, having guts, thinking or even existing. They can also complain that the world or time have ceased to exist. In this article, I argue that even though the leading neurocognitive accounts have difficulties meeting that task, we should, and we can, make sense of these bizarre delusions. To that effect, I draw on the close connection between the Cotard syndrome and a more common condition known as depersonalisation. Even though they are not delusional, depersonalised patients seem to have experiences that are quite similar to those of Cotard patients. I argue that these experiences are essentially characterised by a lack of subjective character and of two other structural features of experience, which I call ‘the present character’ and ‘the actual character’. Cotard's nihilistic delusions simply consist in taking these anomalous experiences at face value.