Study day in tribute to Martin Fortier

Practical information
30 May 2023

ENS Salle Jaurès, 29 rue d’Ulm, 75005 Paris. Remote participation is possible via this link EHESS webinar.


Martin Fortier


Organisation : M. Arcangeli and J. Dokic, with the support of the Institut Jean Nicod

In 2020, Martin Fortier, a doctoral student at the EHESS attached to the Jean-Nicod Institute, passed away prematurely, on the verge of defending a thesis of nearly 600 pages. With his two initial training courses in philosophy and anthropology, his research has a strong interdisciplinary dimension, at the crossroads of the social sciences and the cognitive sciences. His published work focuses on the epistemic and ontological status of hallucinations, on feelings of reality and hyper-reality, on spiritual experiences and shamanism, on altered states of consciousness and more generally on the diversity of consciousness.

This study day honours the memory of a remarkable young researcher by addressing some of his favourite themes.

The presentations are in English, and the round table will be in French and English.





10am-11:15am Juan C. González (UAEM, Cuernavaca), “Classification, reality and epistemic value of psychedelic hallucinations”

11:15am - 12:15am David Dupuis (INSERM, IRIS), “Can psychedelics really change the world ? Hallucinogenic substances and cultural evolution”

Lunch break

2pm - 3pm Joëlle Proust (CNRS, IJN), “Metacognition and cultural evolution” [recorded presentation]

3pm - 4pm Raphaël Millière (NYU), “Dimensions of Consciousness”

Coffee break

4:15pm - 5:15pm Géraldine Carranante (IJN) & Michiel van Elk (Leiden University), “Minding the Mystical : A Network Approach to PRSM experiences”

5:15pm - 6:15pm Roundtable discussion



Joëlle Proust (CNRS, IJN)

"Metacognition and cultural evolution"

Martin Fortier and I organized the first international conference on metacognitive diversity, meant to explore how cultural practices influence the evaluation of uncertainty about one’s own cognitive goals and subsequent decision-making (in cognitive actions such as learning, remembering, discriminating what is real). In the wake of the conference, we edited and prefaced a collective book, including proposals from anthropology, psychology, linguistics, philosophy, and neuroscience (Metacognitive Diversity, OUP, 2018). My talk will concentrate on how metacognitive mechanisms that control cultural accumulation have themselves been subject to cultural evolution. A plausible sequence of evolutionary steps has developed from curiosity-based exploration to inquisitive communication and to collective epistemic deliberation. Procedural metacognition, based on affective monitoring, regulates curiosity and early forms of inquisitive communication. Explicit metacognition enriches these early forms of evaluations through concepts, rules and practices used in the regulation of collective epistemic deliberation. On this view, mindreading first emerged to enhance the quality of collective deliberation.


Juan C. González (UAEM, Cuernavaca)

"Classification, reality and epistemic value of psychedelic hallucinations"

In this talk I will first delve into Martin Fortier’s idea that a strong link can be established between the phenomenology of psychedelic hallucinations and their neuropharmacological bases. I will pursue this idea in order to clarify the kind of link this could be, and whether it provides in principle a solid ground for classifying ––or perhaps even explaining ?–– psychedelic hallucinations. In the second part of the talk I will discuss the ontological status of psychedelic hallucinations and their epistemic value, if any (a subject Martin Fortier was very much keen on). I will argue that 1) the ‘real’/’unreal’ divide is not apt to capture the essential attributes of psychedelic hallucinations nor, therefore, able to illuminate the nature of psychedelic experience ; 2) our habitual conceptual resources get modified during a psychedelic experience, which in turn modifies the habitual match between our perception and semantics. This constitutes a genuine cognitive change, for good or ill, not only making notions like veridicality ill-suited for assessing the ontological status of the hallucinogenic episode or its content, but also 3) leaving open the question of whether a hallucinogenic state is or can be a truly cognitive state, providing thereby knowledge to the subject of the experience. 


David Dupuis (Musée du Quai Branly, Paris)

"Can really psychedelics change the world ? Hallucinogenic substances and cultural evolution"

Since the 1960s, psychedelics have been thought of as powerful tools for transforming societies. In the context of the renewed interest in these substances by the general public and the scientific community, these claims have found new echoes in recent years. Recent studies suggest, for example, that these substances are likely to transform users’ political positions, metaphysical beliefs or relationship with nature. Without denying the fact that psychedelics have their own affordances embodied in their neuro-pharmacological properties, the hallucinogenic experience remains strongly shaped by the norms and values of the social groups of those who use them. Rather than opting for a seductive but angelic approach – seeing psychedelics as substances capable of “healing the world” – or a repressive approach based on the fear of seeing these substances become tools for “brain washing”, I will propose in this talk to focus on what makes these substances unique among the large family of psychotropic drugs : their great sensitivity to extraphamarcological factors. Continuing here debates held with Martin Fortier over the last decade, I will show that rather than tools of social transformation, psychedelic substances appear in the light of anthropological analysis as powerful vectors of cultural transmission.


Raphaël Millière (Columbia University)

"Dimensions of Consciousness"

In recent years, a debate has emerged regarding the adequate characterization and taxonomy of global states of consciousness, a notion that loosely refers to “ways of being conscious” by contrast with specific conscious contents. Examples of global states of consciousness include the ordinary wakeful state, post-comatose disorders of consciousness, and the dreaming state associated with rapid eye movement sleep. The traditional view in clinical neuropsychology is that global states of consciousness can be ranked on a scale corresponding to levels of consciousness, from the “least conscious” to the “most conscious” state. This view has recently been criticized on the grounds that global states of consciousness differ from each other in more than one respect, and thus cannot be easily ranked from least to most conscious. Building upon some ideas outlined in Fortier-Davy & Millière (Neuroscience of Consciousness, 2020), I will raise a number of outstanding questions regarding the multidimensional account of global states of consciousness, and offer some suggestions to address them. In particular, I will draw from dynamical systems theory to explore the idea that global states can be modelled as attractors in a multidimensional space.


Géraldine Carranante (IJN) & Michiel van Elk (Leiden University)

“Minding the Mystical : A Network Approach to PRSM experiences”

Progress in the scientific study of psychedelic, religious, spiritual and mystical (PRSM) experiences is hindered by methodological and conceptual confusion. At a methodological level there is a lack of agreement on the scales and instruments used to measure and categorize PRSM experiences. At a conceptual level, existing typologies (such as trigger-based, phenomenology-based, attribution-based, neurobiological and psychopathological approaches) face difficulties with demarcating different categories of experience and in organizing the field of investigation in a clear and productive way. We propose a conceptual engineering approach to mitigate these problems and to set the stage for the development of a new network tool to study PRSM experiences. In this chapter we lay out the epistemological foundations of such an approach, arguing that scientific progress can be made through an iterative process of conceptual refinement. On this approach, PRSM experiences can be conceived of as a network of symptoms, in which different clusters of experiences can be identified. At a methodological level, network-based models offer the potential to calculate network properties (e.g., centrality measures), while at a conceptual level they offer flexibility in terms of the symptoms that can be included in the network (these could encompass features of experience, as well as contextual, social and biological features). We argue that a network-based model outperforms existing conceptual approaches for fostering current scientific research and we discuss the ontological status of identified clusters of symptoms. While we do not provide a final characterization of PRSM experiences, we are hopeful that our approach can be used as a useful conceptual tool to conduct the hard work of conceptual refinement and theory formation.