1 Introduction

Since the 2000s, psychiatric literature has been largely influenced by contributions in theoretical phenomenology, with remarkable advances concerning Schizophrenia Spectrum Disorders (SSDs). These have been described as alteration of self-consciousness (Georgieff & Jeannerod, 1998), ipseity disturbances (Sass & Parnas, 2003) as examined by the EASE instrument (Parnas et al., 2005; Raballo et al., 2021), anomalies of the minimal self (Cermolacce et al., 2007), disturbances of agency (Jeannerod, 2009), disorders of self-awareness (Kircher & Leube, 2003), or disorders of the sense of self (Davidson, 2020). Although these models represent important descriptive progress, the reader may feel confused by the multiplicity of definitions and the different levels at which the disorder is said to be situated.

The concept of ipseity itself has a rather dizzying polysemy (Strawson, 1999), and so it has been useful to strive to reduce its meaning to a minimal conceptuality identifying a minimal essential feature of what it is like to be a self. There have been recent debates about how far we can reduce ipseity without losing it completely or sacrificing its phenomenological dimension for a purely formal and analytical concept (e.g. Guillot, 2016, Ratcliffe, 2017, Ciaunica & Fotopoulou, 2017, Zahavi, 2017, Zahavi, 2020).

When it comes to psychopathology, various levels of impairment of the experience of the self are highlighted depending on whether researchers are interested in SSDs (Sass & Parnas, 2003), anxious depersonalization (Sass et al., 2013), borderline personality disorders (Fuchs, 2007, Lo Monte & Englebert 2018, Bois et al., 2023) or other disorders. Concerning the most profound anomalies of self-experience, foremost in schizophrenia, it has been shown that it is the minimal core of ipseity that is affected. At the same time, some conceptual models might suggest that the minimal self is so minimal that it can hardly be affected at all, arguing that without a minimal self, there can simply be no experience at all (Zahavi, 2017). This may however lead to the conclusion that pathological experience is impossible to describe with the help of this notion.

We can observe an opposite tendency in defining the minimal self when it comes to theoretical phenomenological philosophy and phenomenological psychopathology: whilst the definition of the minimal self in philosophy gets more and more minimal, approaching almost a pure form, psychopathology literature has explored the affective depths of selfhood. This is understandable, given the need to describe disturbances within a space that is not too full of presence or too thin to be altered. To illustrate this, we can take two papers published in 2017 and 2016 of Zahavi, and Parnas and Henriksen respectively. Whilst Zahavi thrives to a radically minimal definition, arguing that the minimal self simply refers to the idea that “subjectivity is a built-in feature of experiential life” meaning that “the what-it-is-likeness of experience is essentially a what-it-is-like-for-me-ness.” (Zahavi, 2017), Henriksen and Parnas insist on the idea of an “affective sense of self-presence, self-familiarity or self-intimacy” (Parnas & Henriksen, 2016). Although these definitions might seem very similar at the first sight, they have rather different implications. Indeed, an overly minimal concept of ipseity may run the risk of no longer being able to account for the disorders of the self. By saying that a minimal self is always there, even in the altered states of self-experience (Zahavi, 2017), the very notion of the minimal self risks no longer having the descriptive force to account for what happens in schizophrenia. It is therefore necessary to account for the thickness of the self, even in its thinnest dimension. The affective dimension of the minimal self permits to thematize a tacit and operative layer of experience where “passive syntheses” operate without the intervention of an ego, forming the element of self-consciousness and self-world relatedness (Parnas & Henriksen, 2016). Insisting on the dimension of affectivity against the idea of a formal for-me-ness might open the way to a descriptive analysis of anomalies of self and world experience. These issues related to the phenomenological concept of ipseity have recently been discussed by the protagonists of this debate to find a somehow common ground (Henriksen et al., 2019). They propose a rather suggestive metaphor of what happens to the minimal self when it is affected by schizophrenia. They use the image of a syrup colouring the water of consciousness, thus changing the lived quality of subjective experience.

The challenge is to understand this metaphor and translate it into concepts. How can we account phenomenologically for this newly found thickness of the minimal self that is expressed by the elemental metaphor of the water? In this paper, we propose to complement this analysis with a more embodied dimension of affectivity in order to account for the materiality of such an experience in ordinary and pathological situations. We argue that the notion of coenesthesia can offer such a conceptual translation of this metaphor and is able to provide a decisive addition to the debate on the thickness of minimal self.

To this end, we propose to reinvest the neurophysiological and philosophical concept of coenesthesia to give flesh to the minimal self. Traditionally the notion of coenesthesia refers to an inner, visceral feeling of existence and of being a self. It later become a central notion in the French tradition of psychiatry up until the first part of the twentieth century (Ey, 1973; Fuchs, 1995; Starobinski, 1977). Jean-Paul Sartre, as well as Michel Henry and Marc Richir took up this notion to develop genuinely phenomenological concepts, nevertheless, these remain rather peripheral in their respective work. It should also be noted that these three authors invested this concept from different perspectives and for different heuristic needs. The task of phenomenologically understanding coenesthesia remains thus open.

We propose to phenomenologically reinvest this concept by introducing it into the model of the minimal self and its disorders. Here we mainly draw on Sartre's notion of coenesthesia since it is the one closest to the elemental metaphor of water proposed by Henriksen, Parnas and Zahavi. Sartre puts forward an ontological reading of this notion, which we contrast with Matthew Ratcliffe’s recent descriptions of feelings of being. We briefly discuss the limits of such an existentialist notion and of overemphasizing the worldly pole of the experiential relation. We then propose to lay out the implications of this notion for a phenomenology of the self, by tracing the conceptual history of coenesthesia to uncover its physiological origins. We carry out a conceptual archaeology of coenesthesia departing from Hübner and Reil’s invention in neurophysiology. We then move on to Maine de Biran's philosophical appropriation of the concept with his idea of inner tact. Despite almost completely disappearing from psychiatry, the concept is still in use to describe symptoms, exemplarily in the Bonn Scale for the Assessment of Basic Symptoms (Gross et al., 1987). This suggests that there is a coenesthetic dimension specific to at least some schizophrenic experiences, as suggested by Gerd Huber (1957). Our aim is to sketch out a sufficiently broad phenomenological notion of coenesthesia to show how its disturbances play a role in the disorders of the minimal self.

1.1 The translucent matter of consciousness and the feelings of being

1.1.1 Sartre’s notion of coenesthesia in Being and Nothingness

In Being and Nothingness, Jean-Paul Sartre discusses the body as it is for itself (and not for others, or in itself). He describes it as an existential structure of consciousness. He claims that “the relation of consciousness to the body is an existential relation.” (Sartre, 1998, 329). This means that consciousness does not relate to the body as it does to an object through positing intentionality – although it can, through reflection – but it exists its body on the un- or pre-reflective level. Here the verb “to exist” must be understood in a transitive sense. To exist one’s body means that the body is not primarily an object of possession. First and foremost, we do not have an objective body, given to us mediately, through sensations or the images that we can make of it, nor does it reveal itself as a tool we manipulate to do things in the world. The existential body is not an object at all, but a dimension of being and of being conscious. By existing, consciousness is its body, or – to avoid the equivocality of the possessive “its” – consciousness exists the body it is. “The body belongs then to the structures of the non-thetic self-consciousness” (Sartre, 1998, 330), which has already been the subject of Sartre’s early philosophical work, The Transcendence of the Ego, where he first drew a strict and crucial difference between the translucent consciousness and the things that appear through it, like does a “pebble at the bottom of the water” (Sartre, 2004, 9).

To refer to consciousness that is its body without positing it, Sartre uses the term “consciousness (of) the body”. The brackets are meant to underline the fact that the preposition “of” does not refer to an intentional and thus positional relation between consciousness and the body. One could say that the genitive “conscience du corps” is neither a genitivus obiectivus, nor a genitivus subiectivus, but comes closest to a genitivus materiae (of which the grammatically correct form would be “conscience de corps”), as one speaks for example of a wheel of cheese. Rather than being something that consciousness aims at, it is itself a structural feature of consciousness, its element or, as Sartre puts it, its “very texture” (Sartre, 1998, 331), its “translucent matter” (Sartre, 1998, 333), that Sartre identifies with an “original affectivity” (Sartre, 1998, 330). Everything depends on understanding this original affectivity.

In contrast to Scheler, who grasps this affectivity as a hyletic stratum, for Sartre “it is simply a matter of the way in which consciousness exists its contingency” (Sartre, 1998, 331). One might wonder why it would be problematic to recognize a hyletic dimension to original affectivity, but the answer is clear: traditionally hyletic components are considered to enter the noematic side of intentional correlation, i.e., the side of the constituted object, whereas the original affectivity Sartre speaks of should be thought as an affectivity of every noesis. The translucent matter of consciousness is a matter of intentionality itself, and not of what is aimed at through intentionality. To take up the metaphor of Sartre, it is the elemental matter of the water and not the pebble seen at the bottom of the water, through the water. This elemental matter is not constituted at all (since intentionality does not constitute itself), rather it belongs to the contingency and the facticity of existence.

By referring to the contingency of existence, Sartre draws here on the Heideggerian theme of being thrown (Geworfenheit) and always already finding oneself in the world and in a situation. The Heideggerian term for this latter is Befindlichkeit, which he explicitly relates to affectivity, or more precisely to what he describes as mood (Stimmung) (Heidegger, 1962, 174–176). We always already find ourselves affected in the world; the world opens up with this dimension of affective tonality. Nevertheless, unlike Heidegger, Sartre does not identify this existential bodily background of existence with one specific Grundstimmung. When describing original affectivity Sartre notes that “[t]his can be pure grief, but it can also be a mood, an affective, non-thetic tonality, the pure agreeable, the pure disagreeable. In a general way, it is what is called coenesthesia.Footnote 1” (Sartre, 1998, 331). Coenesthesia traditionally refers to an inner, visceral feeling of the body, responsible for mood and even constituting personality or character. Sartre proposes a genuinely phenomenological notion of coenesthesia. He emphasizes that it is difficult to have a pure and immediate intuition of this coenesthetic affectivity since it “rarely appears without being surpassed towards the world by a transcendent project” (Sartre, 1998, 331). Indeed, the coenesthetic affectivity, insofar as it constitutes the translucent matter of consciousness, almost never manifests itself in the foreground – except for what would be a reversal of the background and the foreground, or a dissolution the distinction between the two, resulting in a major disturbance in experience.Footnote 2

This background feeling can be more or less intense. The intensity of the background feeling, which is surpassed toward the world and its objects, related to my projects, appears indeed with different intensities and a different “taste” in grief, in anxiety, when I am in pain or when I feel myself and the world light and floating in the brightness of joy. Pain and pleasure contribute to the background feeling through which the objects are given to me, they dye the translucent matter of consciousness. But even in the lack of pain and pleasure, there remains an affective “taste” of existence in its contingency:

“Coenesthetic affectivity is then a pure, nonpositional apprehension of a contingency without colour, a pure apprehension of the self as a factual existence. This perpetual apprehension on the part of my for-itself of an insipid taste which I cannot place, which accompanies me even in my efforts to get away from it, and which is my taste - this is what we have described elsewhere under the name of Nausea. A dull and inescapable nausea perpetually reveals my body to my consciousness.” (Sartre, 1998, 338).

Coenesthetic affectivity is the first existential determination of self-consciousness in its ineluctable facticity preceding the positional consciousness of an object. According to the thesis developed already in The Transcendence of the Ego and maintained in Being and Nothingness, “every positional consciousness of an object is at the same time a non-positional consciousness of itself.” (Sartre, 1998, liii; see also Sartre, 2004, 7–8). Although non-positional, consciousness is not “blind”, but it is already a kind of self-apprehension. As coenesthetic affectivity, it is a non-positional, affective self-apprehension constituting the existential self in its facticity. The self always already finds itself affected in its own facticity, even when there is no pain or pleasure, no agreeable or disagreeable, like in what Sartre calls nausea. This more or less tinted self-affection, that reveals my body to my consciousness is the Sartrian phenomenological notion of coenesthesia.

1.1.2 Feelings of being and the limits of the ontological-existential approach

By anchoring this original existential affectivity in the body, Sartre remedies a lack in Heideggerian analyses. As Matthew Ratcliffe has also recently put it, we can indeed recognize a “weakness in Heidegger’s account of mood”, namely “that it does not address the role played by the body in experience” (Ratcliffe, 2008, 55). Coenesthetic affectivity on the other hand is conceived as the most basal bodily affectivity that reveals the world to the self and the self to itself in its facticity. In this sense, coenesthesia can be viewed as a specific existential feeling, in the sense that M. Ratcliffe gives to this notion. Indeed, already through history, coenesthesia has often been described as a more or less vague feeling of bodily existence. According to Ratcliffe, existential feelings or feelings of being are “non-conceptual feelings of the body, which constitute a background sense of belonging to the world and a sense of reality.” (Ratcliffe, 2008, 39) Furthermore, Ratcliffe refers on several occasions to Sartre’s Nausea to give an example of an existential feeling. (Ratcliffe, 2008, 71–72, 112, 153) Echoing Sartre’s observation on the difficulty of phenomenologically grasping coenesthesia, Ratcliffe notes that existential feelings “are most amenable to phenomenological reflection when they shift.” (Ratcliffe, 2008, 40) It is through contrasts that the background feeling appears the most: for example, when the background mood switches from a heavy and dark atmosphere to a light and bright way of being in the world, like when the Sun comes back after a storm on a summer afternoon. One might thus understand the notion of existential feeling as a version of Sartre's coenesthesia.

Yet coenesthesia does not exactly refer to the same phenomenon as the term existential feeling. Although existential feelings are indeed bodily feelings, they are more about the world or reality. The accent is put on the role that existential feelings play in disclosing a world. Even if coenesthetic affectivity influences how the world is disclosed for the self and on the feeling of reality, it is more about the body itself as the very fabric of self-consciousness. It is a feeling of being embodied. Or, more precisely, rather than being one existential feeling, cenesthesia is more like a spectrum of a multiplicity of feeling more or less (dis)embodied. It would in this sense be the purely bodily side of existential feelings. The accent here is to be put on the genuinely “material” dimension of coenesthesia as it describes the “matter” that is the lived body, i.e., the translucent matter of consciousness. If we take Sartre’s insistence on the translucent matter seriously, we can say that it is not the world itself, nor the world as a structure of significativity (Bedeutsamkeit)—be it affectively laden—but the more or less thick and dense medium in and through which the world appears that he aims at when he describes coenesthetic affectivity. Nevertheless, Sartre also gives primacy to the spontaneity of consciousness, which transcends its own facticity to act in the world and rejects a hyletic the materiality of the body.Footnote 3 Just as the sign that is surpassed toward the meaning (Sartre, 1998, 330), the body is but a necessary “obstacle to be surpassed in order to be in the world” (Sartre, 1998, 328). Thus its phenomenological materiality always appears deferred, in an après-coup: “the body, since it is surpassed, is the Past”. (Sartre, 1998, 328).

Coenesthesia is primarily in the background, shaping our perception of the world just like variations of the density, transparency or temperature of water alter our vision and sensations of what appears through and in it. Coenesthesia not only allows us to experience the external world but also enables us to feel our own existence. During moments of unease, illness, or intense enjoyment (described with a powerful sensitivity by Levinas in Totalité et infiniFootnote 4), coenesthesia becomes the focus, interrupting our spontaneous connection with the world. Understanding this strictly immanent aspect of coenesthesia, which Sartre and Ratcliffe seem to have underestimated, is crucial. However, comprehending our own embodied existence, or how “the water feels itself” is challenging as we must set aside any foreground against which to compare it. To explore how disturbances of the self can affect coenesthesia in psychopathological experiences, we need to grasp the feeling of our embodied existence and delve into the passive layers of the body that precede our engagement with the world. Therefore, we suggest returning to the foundational texts on coenesthesia from the eight and nineteenth centuries, which approach the body’s self-perception in a non-phenomenological manner. That these texts were not written from a phenomenological perspective is rather an advantage for us, insofar as they allow to bracket the central concepts that push coenesthesia into the background such as intentionality, projects, worldly structure, situation. By examining the body's material dimension, free from intentional acts and worldly structures, we can better understand how coenesthesia serves as the medium for the bodily feeling of existence.

1.2 The concept of coenesthesia in its pre-phenomenological sense

1.2.1 The historical background

The history of the notion of coenesthesia is rather complicated (Fuchs, 1995; Starobinski, 1977). Even the spelling of the word varies between different epochs and languages, and its translation does not make it easy to trace all the threads of its usage and transformations (coenesthesia, cenesthesia, coenaesthesia in English, Zönästhesie, Coenästhesie or Gemeingefühl in German, coenesthésie or cénesthésie in French; furthermore, it is sometimes used in singular other times in plural, which has major conceptual consequences). The word coenaesthesis in the sense we use it since then, appears in 1794 with the inaugural dissertation of Christian Friedrich Hübner, a student of Johann Christian Reil, a prominent figure of German romantic medicine. It is coined from the Greek koinè aisthesis, common sense, but instead of being an intersubjectively common sense, it rather designates an intermodal or pre-modal sense that cannot be reduced to the five traditional senses. In this respect, it is closer to the Aristotelian problem of the common sensibles (koina) without at all being identical to it (Starobinski, 1977). If one would want to identify a precursor for the notion of coenesthesia it would be more accurate to refer to the idea of a feeling of existence (sentiment d’existence), formulated by Malebranche in contrast to the cartesian cogito and taken up by authors of the French enlightenment (Malebranche, 1967, 103, see also: Spink, 1978, Vigarello, 2014). Already in Malebranche, this feeling of being is a bodily feeling, and the main question is how to describe this body that can feel not only the exterior objects, but itself and its own existence, and in which one can feel that one exists. Lelarge de Lignac speaks of a specific sense of the coexistence of one’s own body and of an inner sense (sens intime; Lelarge de Lignac, 1753). The article on “Existence” in the Encyclopédie discusses the idea of an inner tact (tact intime) and mentions “some metaphysicians” who speak of a sixth sense (Turgot, 1754). This feeling of a bodily existence is progressively linked to visceral feelings, a feeling of the interiority of the body, ranging from pure sensations to emotions, constituting an affective background radiation from which the objects of the world and the self detach by their specific salience. It is this background feeling that constitutes the feeling of coexistence of our body, through what Turgot describes as “a multitude of confused sensations which never abandon us, which circumscribe our body in a way, which make it always present to us” (Turgot, 1754, 520, transl. by the authors). Historical physiology and neurology led to exploring the bodily feeling of existence, including awareness of one’s own body. Coenaesthesis, introduced by Hübner and Reil, aligns with this research focus in medicine.

The concept of the nervous system progressively replaces the traditional theory of humor in the explanation of feelings. The body is no longer conceived of as a mere container of different types of bodily vital fluids but acquires a specific reflexivity of its own, made up of nerves that form an entire system. Indeed, the nerves do not only convey information about the world and external objects through stimuli but at the same time continually inform us about the state of our own body. The feeling of existence, the sense of the coexistence of our body, this multitude of obscure and vague sensations that never abandon us finds here an epistemological grounding: the feeling of being an embodied self is the specific feeling through which the reflexivity of the nervous system is constituted. It is this specific feeling that Hübner and Reil call coenaesthesis:

“The nerves [...] possess the ability to work backwards (rückwärts wirken) and to maintain in the soul a certain obscure feeling about the existence (Daseyn) of the body and its states. Almost all the parts of the body are woven through with nerves, which terminate in these very parts with numerous and soft rootlets. The parts in which they are incorporated (einverleibt) exert a continuous pressure on these soft ends of the nerves, through which the soul perceives, in every instant, the existence (Daseyn) of its body and its individual parts through obscure feeling (dunkle Gefühle).” (Hübner, 1794, 230-231, transl. by the authors)

The specific reflexivity of the body through which the obscure feeling of its existence is constituted is explained by the capacity of the nerves to “work backwards”, by this coiling, this turning inwards of sensibility itself. The organ of sensibility that is the body senses its constituting through a purely sensible reflexivity, without the intervention of an intentional or volitional act of consciousness. This purely bodily reflexivity becomes conscious through the mode of an obscure feeling, emanating from the depths of the body. The idea of an inner tact is explained here by the continuous pressure that the parts of the body exert on the totality of the nervous system resulting in a multitude of obscure feelings that never abandon us. One should however note the ambiguity of the passage: first Hübner speaks about a certain feeling of the existence of the body in singular, then about a “working backwards” of the nerves, and finally of a multitude of feelings that arise through a constant pressure that the parts of the body exert on the endings of the nerves. While the nervous system provides a foundation for the connection between bodily reflexivity and the vague feeling of existence, the core nature of this reflexivity remains enigmatic.

In the French philosophical scene, Maine de Biran was not only aware of the newest ideas in medical and physiological research of his time, but in 1823 he even translated some parts of texts of Hübner and Reil and probably introduced the term coenesthèse to the French language (Azouvi, 1995, 416, Baertschi, 1990, XIX). But interestingly when he translates the above-quoted passage, he introduces a notion that cannot literally be found in the German original of this passage: that of a “pulp”Footnote 5 that surrounds the nerves (Maine de Biran, 1990, 125). The pulp becomes here the very matter and milieu, the element of the coiling of sensitivity on itself, constituting this peculiar feeling that is coenesthesia. In this element, sensitivity is not in contact with something else, with something heterogenous, but with itself, without constituting objects or a world. It is an inner space (étendue intérieure) without objects but with a specific thickness and density, where pressure, contraction and releases propagate according to constant variations of the effort and the resistance it meets—the contact between the effort and the resistance being the primordial fact (fait primitif) for Maine de Biran, i.e., a feeling of being in “in touch” with oneself, a feeling of being in contact with oneself that constitutes a basal, “archaic” version of the cogito. The only thing that is eventually instituted upon this mass of sensations and feelings are the parts of the body, or what a century later would be called the body schema (originating in the works of Pierre Bonnier in France, and Henry Head and Gordon Holmes in England; see Fuchs, 1995; Vigarello, 2014, 182–203). However, the pulp precedes genetically this schematization of the body as an objectless and shapeless element at the basis of this obscure and blurry feeling that we have of the existence of our own body.

1.2.2 Disturbances of coenesthesia

Hübner and Reil insist on the fact that coenesthesia emanating from the neurological depths of the body normally remains unthematic for consciousness in the state of health. “Coenesthesia is weak and confused in a healthy state so that the soul in its operations is not disturbed by the countless impressions” (Hübner, 1794, 234). The vague feeling of the existence of the body is relegated to the background and we are mainly in contact with exterior objects. An overly thematic presence of coenesthesia would obstruct external perception and would render consciousness directed towards the outside world opaque by disturbing the soul in its operations. On the contrary, in a sick body, coenesthesia has increased intensity and appears stronger (ibid.). According to the intensity, the disturbance of the soul's operations that are directed towards the external world and its objects is also weaker or stronger. Some examples of Hübner are hunger, thirst, fatigue, contractions, fever, or anxiety (ibid., 242–245), all related manifestly to the medical point of view on the organic body. However, in Maine de Biran the variations of coenesthesia also acquire a more general dimension. In a captivating passage of his Journal Maine de Biran, clearly inspired by these analyses, writes the following:

“The bad coenesthesis, all the anomalies of this vital sense which never remains the same for two moments, all the involuntary aberrations of the imagination: one must bear all this, that is to say bear oneself, like a fever. Is not our sensitive existence a continuous fever?” (October 1823, Maine de Biran, 1931, 321, transl. by the authors)

The notion of (sensitive) existence as fever captures an existential feeling akin to Ratcliffe’s concept. Nevertheless, the accent is less put on the relation to the world, and more on the relation of the self to its own existence: one must endure one’s own sensitive existence, and thus one’s own body, as a continuous fever. The body is the site where the self is assigned to itself, coenesthesia is the element of ipseity in which one must bear oneself, for the better or the worse.

The idea that coenesthesia is the element in which the self relates to itself or even in which this inchoate bodily reflexivity becomes a feeling of being a self had a major influence on historical French psychiatry. In his landmark treatise on hallucinations from 1973, Henri Ey, who played a highly influential role in French psychiatry during the twentieth century, notes that for some time the disorders of coenesthesia were understood as cases of depersonalization:

“Storch and Foerster, Wernicke, by basing the consciousness of the Ego on the sensations received in its body (an old sensationalist thesis that Locke, Condillac, Taine, etc. had widely propagated) with the notion of coenesthesia, had prepared that of depersonalization. In 1898, Dugas published a memoir in the Revue Philosophique which consecrated this term. The work of Ribot, Séglas, Sollier, Deny and Camus familiarized the whole French psychiatric school with the idea that depersonalization and coenesthetic disorders were, so to speak, synonymous.” (Ey, 1973, 294, transl. by the authors)

The argument is clear: since the consciousness of the ego is founded in a pre-egoic bodily affectivity (here a purely sensationalist affectivity), the disorders of this latter can cause disorders of the former. We argue that this idea stands not only in an empirical or sensationalist view but also in phenomenology. The “pulp” or the bodily element of the formation of the self can phenomenologically be grasped as the element of the flesh.

Depersonalization is related to phenomena like mine-ness or me-ness, or for-me-ness which are phenomenological qualities of experience. Jaspers describes depersonalization exactly in these terms:

“Every psychic manifestation, whether perception, bodily sensation, memory, idea, thought or feeling carries this particular aspect of ‘being mine’ of having an ‘I’-quality, of ‘personally belonging’, of it being one’s own doing. We have termed this ‘personalization’. If these psychic manifestations occur with the awareness of their not being mine, of being alien, automatic, independent, arriving from elsewhere, we term them phenomena of depersonalization.” (Jaspers, 1963, 121).

Furthermore, Jaspers notes that “[t]he experience of one’s body as one’s own is phenomenologically closely linked with the experience of feeling, drive and awareness of self.” (Jaspers, 1963, 89) From a phenomenological point of view, coenesthesia is precisely the base of this obscure feeling of one’s own body as one’s own, that dyes the experience that the self has of itself and of the world. Mine-ness and me-ness are not mere analytical features of selfhood, but they have an experiential quality of bodily density.

The notion of coenesthesia intimately connects the feeling of being embodied and of mine-ness. In the transcendental tradition, mine-ness is mostly conceived of in the vague line of a Kantian heritage an operative synthesis depending on the ego-pole, that is the noetic side of the correlation. As Kant famously put it: the “I-think must be able to accompany all my representations; for otherwise something could be represented in me that could not be thought at all, which is as much to say that the representations would either be impossible or else at least would be nothing for me.” (Kant, 1998, 246/KRV B 131). Defining the minimal self with the notion of for-me-ness also accentuates this pole character of selfhood. On the other hand, the notion of coenesthesia refers to an affective and bodily depth from which selfhood emerges. The self is first and foremost an obscure and vague embodied feeling of being in contact with oneself. And coenesthesia is nothing but the bodily-material element or milieu of this contact, having its specific density and variations, and which thus accompanies all other feelings, moods, and even the soul’s silent dialogue with itself. The noetic pole finds its anchor in coenesthesia, which accompanies the “I think” so to speak from below. Drawing inspiration from the Sartrian definition of coenesthesia as the translucent matter of consciousness, we can perceive the “pulp” not as an empirical element around the nervous system, but as the core density and viscosity of the self’s affectivity. In this sense, coenesthesia helps elucidate the water metaphor in Henriksen, Parnas, and Zahavi’s explanation, enabling further exploration of disorders affecting the minimal self.

1.3 Coenesthesia and the disturbances of the thickness of the minimal self

The gradual disappearance of this notion once central to different psychiatric traditions can be explained by the fact that it has progressively been replaced by other concepts trying to grasp more accurately some of its functions or by notions that stem from different theoretical frameworks: e.g., proprioception, interoception, body schema, body image, etc. Today, despite a few notable exceptions (e.g., Fuchs, 1995; Graux et al., 2011; Jenkins & Röhricht, 2007; Stanghellini, 2004), it mostly remains a conceptual fossil whose history has for the most part been forgotten. Instead of being a central operative notion, it appears in manuals of contemporary psychiatry describing hallucinatory symptoms, mainly in schizophrenia, or an unspecific “change in the normal quality of feeling tone in a part of the body” (Flaherty et al., 2011). Some cases of disturbed coenesthesia have been and are still considered as symptoms or an isolated type of SSDs (e.g. “Cenesthopathic schizophrenia” (F20.8) in ICD-10 (World Health Organization, 1993), which disappeared in ICD-11).

In this final part, we argue that coenesthetic experiences are a fundamental component of the schizophrenia spectrum. They signify disturbances in the experiential materiality of the intimate sense of self and its boundaries. Coenesthesia should not be limited to isolated symptoms in SSDs, such as bodily hallucinations. Seen positively as the element of the consistency of the self, coenesthesia, and its anomalies, thus become one of the key factors for understanding the shifts of the minimal contact of ipseity in schizophrenia and the link between “diminished self-affection”, “hyperreflexivity” and “disturbed hold” or “grip” on the world (Sass & Parnas, 2003; Sass, 2004). These disorders of the coenesthetic element of self can be seen as a “trouble générateur”, as described by Minkowski, involving a loss of vitality in contact (Minkowski, 1995, 58).

1.3.1 Coenesthesia in a narrower sense in contemporary phenomenological research on SSDs

Twenty years before the construction of the semi-structured interview EASE (Examination of Anomalous Self Experience, Parnas et al., 2005) by Josef Parnas, Dan Zahavi and their collaborators, coenesthesia has been identified as one of the main categories in psychiatric research on basic symptoms of schizophrenia. Emblematic is the Bonn Scale for the Assessment of Basic Symptoms, a tool conceived as a “survey and documentation of psychopathological and other phenomenological aspects of patients” (Gross et al., 1987, 1). The scale is designed to identify basic symptoms related to Schizophrenia Spectrum Disorders (SSDs) in stages preceding or following episodes of full-blown psychosis. These stages include prodromes or postpsychotic states, as well as the so-called “outpost” syndromes, referring to prodrome-like conditions that do not directly and immediately progress to full-blown psychosis but instead resolve before the later onset of schizophrenia. (For a discussion, refer to Fusar-Poli et al., 2013). The authors of the BSABS emphasize that it can be utilized in cases where a clear diagnosis has not yet been established. It can also be employed in cases of what the authors refer to as “affective psychoses (mon

opolar and bipolar courses of cyclothymia)”, where some of the nonspecific basic symptoms are also present. The focus is clearly placed on the phenomenological and descriptive aspects of the scale, rather than adopting a nosographic classification approach (Gross et al., 1987, 1).

The BSABS lists 15 items in a separate category devoted to coenesthetic experiences. (Coenästhesien). They are described as follows:

“These are disturbances of body sensation (Leibgefühlstörungen) that occur mainly suddenly and paroxysmal and last from seconds to minutes. However, they can also persist for hours to several days, occasionally also continuously over weeks, months and years, according to the patients’ description, and in some cases wax and wane. (Gross et al., 1987, 89, transl. by the authors)”

The authors also highlight the challenging nature of describing certain feelings. The inclusion of coenesthesia as a distinct phenomenological category in the investigation of basic symptoms already recognizes the specificity of certain coenesthopathies associated with SSDs. Additionally, Gerd Huber, one of the authors of the BSABS, has proposed the concept of coenesthetic schizophrenia as a specific subtype (Huber, 1957) and refers explicitly to Dupré and Camus’s cénesthopathies as a precursor to this subtype (Huber, 1971). However, what does this imply for the notion of the minimal self, which is believed to be disturbed in these coenesthopathic experiences?

The EASE aiming more precisely at the phenomenological investigation of SSDs as self-disorders also lists bodily experiences as a separate category, but only one of the items, the 3.7 is labeled as “cenesthetic experiences”. However, a closer look is sufficient to notice that some of the other items listed as bodily experiences also correspond to what traditionally has been described as coenesthopathies per se (e.g. 3.1. morphological changes, 3.3. somatic depersonalization, 3.4 psychophysical misfit and psychophysical split, 3.5. bodily disintegration, 3.6. spatialization of bodily experiences). This suggests that what has traditionally been described as coenesthopathies is a phenomenologically essential structure of ipseity disturbances. The presence of the coenesthetic experiences in both the BSABS and the EASE call for a reconceptualization of the phenomenological aspect of coenesthesia in the case of self-experience. Indeed, as Vollmer-Larsen, Handles and Parnas claim in a recent study “the EASE may be considered as a phenomenological extension of the BSABS in the domain of self-experience” (Vollmer-Larsen et al., 2007, 347). Through this expansion, coenesthopathies can be directly associated with forms of self-disorders. The disturbances of ipseity often unfold as coenesthopathies, or, in other words, the way in which the self is disturbed is coenesthetical. The question arises: how strong is the connection between self-disorders and coenesthopathies, and what does it signify for the phenomenology of selfhood and its disturbances?

We propose a strong notion of coenesthesia by drawing on Sartre’s definition and on the historical background of the notion. Coenesthesia is not merely a bodily experience but the feeling of the body's existence, forming the translucent matter and texture of consciousness. It encompasses a feeling of being in contact with oneself, an intimate tact that is the very core of ipseity. Generally put, coenesthesia can be seen as the milieu or the element of selfhood, with its own density and viscosity. This latter mustn’t however be confused with an empirical materiality. If historical studies on the nervous system discuss a constant pressure and a pulp as the element of an obscure bodily reflexivity, the phenomenological understanding of coenesthesia must distill these notions beyond empirical positivities. What remains is the phenomenological quality of an elemental self, a feeling of being in contact with oneself, a feeling of the tensions and releases of the bodily milieu in which the self relates to itself and through which it relates to the world and to its objects.

In line with Minkowski, we can understand contact with reality as ‘vital’ due to its experiential materiality. It is not a mere realm of pure thought, but rather possesses thickness and vibrancy that are influenced by physiological, ecological, and affective factors. This experiential element, likened to water by Henriksen, Parnas, and Zahavi, remains at the core of the reconceptualized notion of coenesthesia. Drawing from Sartre’s phenomenology of the body as translucent matter and the pre-phenomenological history of coenesthesia, which emphasizes its role in the feeling of the contact of the self with itself in the element of the body, coenesthesia is clinically significant in a phenomenological approach to SSDs.

1.3.2 Coenesthesia in a broader sense in contemporary phenomenological research on SSDs

If we acknowledge the coenesthetic aspect of this material element of consciousness, we can explore other experiential dimensions documented by EASE as coenesthetic anomalies. By expanding the definition of coenesthesia, we gain insight into how fluctuations in the density of embodied existence, as subjectively experienced, influence the fluidity of thought processes. Without being able here to delve into specifics, we can already identify other items in which coenesthesia could be involved, and which would require more targeted, in-depth research.

The first domain of EASE, “Cognition and Stream of Consciousness”, refers to variations in the “normal sense of consciousness as continuous over time, flowing, inhabited by one subject and introspectively transparent (immediately or directly given) in a nonspatial way.” (Parnas et al., 2005, 240) Variations in thought texture can be observed in items such as “Thought Pressure” (1.3) and “Thought Block” (1.4). These experiences can be described by patients as a sudden interruption or emptiness of thoughts, akin to an “air pocket” in their thinking. Conversely, item 1.11, “Disturbance of Thought Initiative”, reflects a modification in the energy or launchability of thoughts, often accompanied by a sense of resistance or excessive viscosity. Additionally, item 1.8, “Spatialization of Experience” highlights how coenesthesia, as the translucent matter of consciousness, becomes disturbed or excessively dense in pathological conditions. What would typically remain transparent and unnoticeable becomes opaque and blurred in schizophrenic thought.

This already aligns with Louis Sass’s concept of hyperreflexivity (see also item 2.6). He made an important distinction between “reflective” (secondary) and “operative” (primary) hyperreflexivity. The latter is described as having “the effect of disrupting awareness and action by means of an automatic popping-up or popping-out of phenomena and processes that would normally remain in the tacit background of awareness (where they serve as a medium of implicit self-affection), but that now come to be experienced in an objectified and alienated manner” (Sass, 2010, 648)—we could recognize here aberrant coenesthetic saliences.

Domain 2 “Self-Awareness and Presence” is based on the idea that “a normal sense of being (existence) involves automatic unreflected self-presence and immersion in the world […] we are directly (noninferentially) conscious of our own thoughts, perceptions, feelings or pains; these appear in a first-person mode of givenness that immediately reveals them as our own” (Parnas et al., 2005, 243). Anomalies of this domain are described as “disturbed self-presence” “often associated with the following clinical features: diminished clarity or transparency of consciousness, diminished sense of vitality or basic aliveness, diminished activity potential or pleasure capacity, diminished sense of attraction by the world, diminished sense of first-person perspective” (Parnas et al., 2005, 244). The variations in the transparency of consciousness appear clearly as variations in the translucid matter that is coenesthesia. Considering that coenesthesia has historically been described as a feeling of self, we can here easily recognize coenesthopathies as anomalies of feelings of being a self or being in touch with oneself, a loss or a rigidification of the consistency of the self. As an existential feeling, going back to Ratcliffe's analyses, it's easy to see how a weakening of this sense of self also alters engagement with the surrounding world.

Domain 4, “Demarcation/Transitivism” presents a challenge in accounting for the intersubjective nature of coenesthesia. While coenesthesia pertains to the materiality of experience beyond the physical boundaries of the skin, we must acknowledge that internal experiences differ from external experiences and our experiences of others. Consequently, the genesis of self-boundaries occurs within coenesthetic experiences, necessitating a genetic and developmental analysis of their emergence during early childhood. However, we can already discern a texture of intersubjective contact that allows us to sense aspects of others' coenesthesia. For instance, phenomena like affective contagion and the Praecox Feeling demonstrate this capacity (Gozé et al., 2017, 2019; Parnas, 2011). Moreover, it has previously demonstrated that the clinician’s experience of strangeness provides direct but enigmatic insight into disturbances of self-experience in individuals with SSDs (Gozé, 2020).

The fifth domain, “Existential Reorientation” requires further investigations into the coenesthetic dimension of Ratcliffe’s existential feelings to elucidate the early stages of schizophrenia described by Conrad (Mishara, 2010) and Huber (1995). While coenesthesia plays a significant role in these experiences, particularly regarding the bodily element, existential approaches clearly possess greater descriptive power. They specifically emphasize existential intentionality and the disclosure of the world. These experiences seem to be more centered on the world rather than the flesh in its phenomenological materiality. However, even in these cases, it can be shown how the coenesthethic element of the body influences the disclosure of the world and how the materiality of atmospheres and moods stems from the element of the obscure feeling of being and being in contact with oneself.

What does this mean for the metaphor of the syrup tinting the water of consciousness, which was our point of departure? We can put forward the thesis that it is not as if in SSD a mysterious syrup would be added to the water of consciousness from outside, but coenesthetic affectivity is always already populated by a multiplicity of vague and blurry feelings, most of them without a name, that become more or less salient in a continuous changing. When coenesthetic affectivity is rigidified or when some of its saliences become aberrant it phenomenologically changes the translucent matter of consciousness, thus resulting in an experiential modification of the element of consciousness. When aberrant coenesthetic elements invade consciousness, this latter is not only entirely dyed, but its density and viscosity are also modified, and then the world also appears through this coenesthetically modified consciousness. Of course, the things and the world, thoughts, and feelings that I experience as mine or as coming from elsewhere continue to be for me. But the overall taste of how they are for me is altered. There is no simple, formal, and general way to describe what it is like for me to have an experience because for-me-ness is always coenesthetically tinted. The dialogue between phenomenology and psychiatry precisely shows the necessity of finding operative notions to describe this coenesthetic thickness.

Coenesthesia does not only concern the lived experience of the physiological or biological body (Körper) but it is the element of the flesh or the lived body as the operative means of experience (Leiblichkeit in German or chair in French). The flesh is a much broader concept in the sense that we can even speak of a flesh of thinking, language, and reflexivity. Just like there are kinestheses accompanying movements of thought, for example when I feel that thoughts are moving too fast or too slow, or when I feel the flight of ideas or when I have a word on the tip of the tongue there are coenesthetic components: thoughts can be heavy or light, more or less fluid or rigidified, having different densities and viscosity (think of a stubborn earworm). Words can appear in their specific materiality (and poetry does not cease to remind us of it), and the element of reflexivity can become more or less transparent or opaque, translucent or resistant. Coenesthesia thus plays a role in every process of sense-making, in the process of making sense of the world or of ourselves. If sense-making is embodied, it is also always coenesthetically tinted. We can thus recognize anomalies of coenesthesia in more items identified in the EASE.

2 Conclusion

The aim of this paper was to investigate the phenomenological thickness and density of the minimal self that is supposed to be altered in ipseity disturbances. How can we describe the alterations of a self so minimal that it is the condition of possibility of all experiences in general, including the disturbed ones? We have adopted the metaphor proposed by Henriksen, Parnas, and Zahavi of water (representing phenomenological consciousness) being colored. By conceptualizing the minimal self in this manner, it implies the existence of a minimal thickness that needs to be explored at this level. To further develop this metaphor, we have revisited the historical notion of coenesthesia. In the context of physiological conceptual history, coenesthesia can be understood as a bodily and tangible thickness of “for-me-ness”. This coenesthetic thickness of “for-me-ness” suggests that the minimal self possesses an elemental character. By referring to the term “elemental”, we are highlighting a phenomenological materiality specific to it—a milieu of phenomenalization with its own density (Fazakas, 2021). When the material structure of this milieu is altered, the phenomena that manifest within it also appear differently (just as in colored water, phenomena will appear in shades of the respective color). Coenesthesia can thus be comprehended as a form of phenomenological materiality.

To elucidate the concept of coenesthesia, we have drawn upon Sartre's definition and the historical development of the concept. Sartre’s notion of a translucent matter of consciousness resonates with Henriksen, Parnas, and Zahavi’s metaphor. However, Sartre emphasizes the existential intentionality that inherently surpasses this coenesthetic affectivity towards situations, objects, and the world. In this regard, coenesthesia can be seen as a bodily foundation for what Ratcliffe describes as existential feelings. While we acknowledge the significance of existential intentionality in every experience, we propose to shift the focus and delve into the depths of coenesthesia. This change in perspective entails bracketing existential intentionality, at least in the initial stage. The conceptual history of coenesthesia provides us with rich descriptive material to further clarify certain aspects of this notion. In this paper, we have mentioned various aspects related to Malebranche's notion of a feeling of existence, the concepts of inner sense or inner tact, and the perception of the coexistence of our body as discussed in 18th-century French philosophy. Additionally, we have explored Reil and Hübner’s research on the nervous system, which led to the term “coenesthesia” itself, as well as Maine de Biran’s early reception of the concept. This line of inquiry has paved the way for the psychiatric notion of coenesthopathies within the French tradition, which is connected to what is now understood as depersonalization and pertains to the experiential quality of something being “personal” in terms of me-ness, mine-ness, or for-me-ness of experience. By looking at the history of the notion, one could say that the definitions are as vague and confusing as the phenomenon they are intended to describe. This paper is nothing but a first sketch of a phenomenological approach, trying to grasp the specificity of this obscure and vague bodily basis of the feeling of being a self. Coenesthesia, as we propose to understand it, is the fleshly-material dimension of the “affective sense self-presence” (Parnas & Henriksen, 2016). Indeed, this notion permits to thematize the materiality of the phenomenological body (Leib, flesh) as a milieu with its own density, that at the borders of anonymity and self-affection gives the sense of self-presence a texture, a material quality.

Anomalies of coenesthesia in psychopathologies are often treated as symptoms, including in research on basic symptoms, early schizophrenia, and Huber's proposed subtype. While recognizing the importance of disturbed coenesthesia in SSDs, current understanding remains narrow. The EASE instrument acknowledges the significance of anomalous bodily and coenesthetic experiences in disturbed ipseity. We propose expanding the meaning of coenesthesia as an intrinsic aspect of self-experience. The phenomenological notion of coenesthesia illuminates the non-empirical materiality and consistency of self-affection, aiding in the analysis of its anomalies in SSDs. Coenesthopathies in multiple regions of ipseity support the idea that coenesthesia relates to the core of the self. This interplay between constructing a phenomenological notion of coenesthesia and confronting clinical tools reveals the elusive and perplexing fleshly element of the minimal self.