“Classic”, serotonergic psychedelic drugs such as LSD and psilocybin are the objects of renewed attention in science and psychiatry. A recent spate of research has produced evidence that psychedelics might be safe and effective adjuncts to the treatment of mood and addictive disorders, agents of positive psychological change in healthy subjects, and valuable tools for studying the neural mechanisms of perception and cognition. This chapter surveys three philosophical debates that have arisen in response to this “renaissance” of psychedelic research. The (...) first concerns the mechanisms of psychedelic-assisted psychotherapy (“psychedelic therapy”): How, exactly, does psychedelic administration in controlled conditions cause lasting psychological benefits? The second concerns the implications of psychedelic research for the philosophy of mind: Does psychedelic evidence show that there can be conscious mental states lacking all forms of self-consciousness? The third concerns the epistemic status of the psychedelic state: Is it possible that certain kinds of knowledge, or other epistemic benefits, could be gained by undergoing a psychedelic experience? (shrink)

Psychedelic-assisted Psychotherapy combines the use of psychedelic compounds, such as psilocybin, with psychotherapy. PAP has shown some promise as a novel treatment for Major Depressive Disorder, and empirical research suggests that its efficacy turns on the altered states induced by psychedelic compounds. In this paper we draw on the literature of phenomenology to explain the therapeutic potential of psychedelic experiences. Svenaeus characterises mental illness as a form of suffering that entails three distinct but related experiences of alienation or “unhomelike being-in-the-world”: (...) illness suffering, which relates to embodiment; existential suffering, which relates to self-narratives, and political suffering, which relates to social relationships. Ratcliffe further characterises the experience of MDD in phenomenological terms as a loss of pre-intentional possibility that manifests as excessive noematic feeling in the experience of embodiment, restrictive narratives in the construction of self, and disconnectedness in experience of the social world. We contend that PAP ameliorates the suffering associated with MDD by inducing and consolidating a state of broadened pre-intentional possibility—one that entails sudden, profound and enduring changes in embodiment, self-narratives, and social experience. We argue further that this phenomenological account is consistent with a bio-psycho-social model of mental health and illness, and we frame it as an argument supporting the plausibility of recent claims about treatment success. This helps to justify ongoing future empirical research in this setting. (shrink)

In Philosophy of Psychedelics, Letheby provides a convincing basis for the idea that psychedelics primarily derive their therapeutic potential through mediating favourable changes to self-related belief systems. In this commentary, we take a closer look at the role that contextual factors play in Letheby’s two-factor account of psychedelic therapy. While Letheby acknowledges that psychedelic effects are highly context-dependent, the exact role that context plays in self-modelling during the acute experience is not entirely clear. We argue that context plays an essential (...) role in shaping the ‘discovery’ of alternate self-conceptions during the acute experience. Specifically, users are more likely to experience alterations in self-conception that are consistent with context-dependent features, such as one’s prior mindset and aspects of the external environment. This is consistent with a REBUS model of psychedelic effects, where a corollary effect of relaxing high-level prior beliefs is that the system becomes increasingly sensitised to bottom-up information from lower-level intrinsic sources and the sensory periphery. Furthermore, it may explain why a positive well-intentioned state of mind and a supportive therapeutic environment are more likely to result in positive acute experiences and long-term improvements in mental wellbeing. We see this position as being largely compatible with Letheby’s proposal, but may shift some aspects of its emphasis and framing. In particular, it may conflict with Letheby’s notion that psychedelics lead to a ‘level cognitive playing field’, where self-related hypotheses are thought to be assigned more or less equal probability. (shrink)

What makes psychedelic psychotherapy work? Is it the induction of psychedelic experience, with its distinct patterns of hallucinations and insights, or is it the neural ‘shakeup’ that moves the brain out of its regular mode of functioning and into a more disordered state? We consider the role that attention-related phenomenological changes play in psychedelic transformation and psychotherapy. We review Letheby’s account of psychedelic psychotherapy, which appeals to increases in phenomenal opacity as the central mechanism of psychotherapeutic transformation. We argue that (...) there is an alternative vehicle of psychedelic transformation that this account overlooks, involving radically transparent experiences. We outline the common kinds of phenomenal transparency shifts typical of psychedelic experiences, and argue that in many cases, such shifts are responsible for the psychotherapeutic benefits. This argument motivates an alternative approach to possible mechanisms of psychedelic self-transformation, and opens up a new venue of empirical research into the role of attention and phenomenology in psychedelic psychotherapy. (shrink)

Much of my book Philosophy of Psychedelics is devoted to elaborating and defending two basic claims: that psychedelic therapy works mainly by changing mental representations of the self, and that it has many epistemic benefits consistent with a naturalistic worldview. The commentaries in this symposium generally focus on one or the other of these claims. On the mechanistic front, the commentaries by Hoffman and by Martin and Sterzer seek to supplement my account by drawing attention to factors it does not (...) emphasize. In this reply I agree with most of their claims, but propose some important qualifications. Meanwhile, the commentaries by Lyon and Farrenikova and by Colombo challenge some core commitments of my account. I agree with many of their claims, but defend some of these core commitments. On the epistemological front, Bortolotti and Murphy-Hollies endorse the overall shape of my account and make some productive connections to ideas concerning agency-first epistemology and self know-how. Caporuscio brings into play the idea of self-shaping, which connects to self know-how, but argues against certain core claims of my account. I endorse many of these claims about agency-first, self know-how, and self-shaping, but propose some important qualifications. Finally, Fink agrees that psychedelic experiences can have some epistemic benefits, but argues that these do not pertain to epistemic justification, and that the main benefit is increased understanding. I am sympathetic to Fink’s proposal about understanding, but criticize some of his arguments for the thesis of Psychedelic Justification Impossibilism. (shrink)

In this précis I summarise the main ideas of my book Philosophy of Psychedelics. The book discusses philosophical issues arising from the therapeutic use of “classic” psychedelic drugs such as psilocybin and LSD. The book is organised around what I call the Comforting Delusion Objection to psychedelic therapy: the concern that this novel and promising treatment relies essentially on the induction of non-naturalistic metaphysical beliefs, rendering it epistemically objectionable. I begin the précis by summarizing material from chapters two and three (...) of the book, which review evidence for the therapeutic efficacy of psychedelics, and the facts about their clinical use that prompt the Comforting Delusion Objection. I then summarize materials from chapters four and five of the book, which argue that psychedelic therapy works neither by experience-independent processes of neuroplasticity, nor by inducing non-naturalistic metaphysical ideations, but by altering mental representations of the self. Next, I summarise the specific, speculative account of how this might work that is developed in chapters six and seven of the book. This account is based on the predictive processing theory of brain function and the self-binding theory of self-representation. Chapters eight and nine of the book argue, on the basis of this account, that psychedelic therapy can have significant epistemic and spiritual benefits that are compatible with a naturalistic worldview. I summarize this material, and then, finally, the overall conclusions about psychedelic therapy drawn in the tenth and final chapter of the book. (shrink)

I highly recommend Philosophy of Psychedelics by Chris Letheby to both the public and academics who want to dig deeper into the modern therapeutic science of psychedelics. In this piece, I will draw attention to key topics covered in the book that I judge as particularly compelling and likely to influence psychedelic therapy and our understanding of it going forward. Clearly, the importance of philosophy in the modern psychedelic therapy renaissance will increase, and Letheby’s Philosophy of Psychedelics will hold a (...) place as a foundational work helping to shape this future. (shrink)

Letheby’s naturalistic theory of psychedelic therapy argues that the therapeutic power of psychedelics lies in their ability to allow individuals “to discover the contingency, mutability and simulatory nature of their own sense of identity and habitual modes of attention.” The general shape of this project is persuasive; it is hard to see how the claim that successful therapy must involve changes to the self could be objected to, and Letheby sketches a consistent, if speculative, picture of psychedelic experience. But the (...) role of affect in psychedelic therapy is insufficiently explored by Letheby as a comparison to MDMA-assisted therapy indicates. This comparison further suggests that Letheby’s reliance on a particular conceptualization of ego dissolution experiences is in need of further explanation and justification. (shrink)

Chris Letheby argues in Philosophy of Psychedelics that psychedelics and knowledge are compatible. Psychedelics may cause new mental states, some of which can be states of knowledge. But the influence of psychedelics is largely psychological, and not all psychological processes are epistemic. So I want to build on the distinction between processes of discovery and processes of justification to criticise some aspects of Letheby’s epistemology of psychedelics. Unarguably, psychedelics can elicit processes of discovery. Yet, I hold, they can hardly contribute (...) either to the epistemic success of a mental state or to processes of justification. As these are central for a mental state to be a state of knowledge and are largely uninfluenced by psychedelics, the contributions of psychedelics to knowledge are rather indirect than direct: The heavy epistemic lifting—what turns a mental state into a state of knowledge—is, in its epistemic aspects, independent of any influence of psychedelics on our psyche. Positively, while the mechanisms that Letheby points to need not be associated with knowledge, they do provide crucial epistemic benefits if they are associated with understanding. Reading them as facilitating understanding covers also those cases where truth or justification is missing and thereby provides a broader picture of the epistemic contributions of psychedelics. (shrink)

Letheby’s "Philosophy of Psychedelics" relies on Predictive Processing to try and find unifying explanations relevant to understanding how serotonergic psychedelics work in psychiatric therapy, what subjective experiences are associated with their use and whether such experiences are epistemically defective. But if Predictive Processing lacks genuinely explanatory unifying power, Letheby’s account of psychedelic therapy risks being unwarranted. In this commentary, I motivate this worry and sketch an alternative interpretation of psychedelic therapy within the Reinforcement Learning framework.

Chris Letheby’s defence of psychedelic therapy hinges on the premise that psychedelic-facilitated insights about the self are in a better epistemic position than those about the external world. In this commentary, I argue that such a claim is not sufficiently defended. More precisely, I argue that one element is underexplored in Letheby’s otherwise compelling picture: namely, that unlike new beliefs about the external world, beliefs about oneself have the capacity to turn into self-fulfilling prophecies. Recognising the psychedelic experience and the (...) subsequent integration process as opportunities not only to apprehend certain facts about the self but also to actively shape and redetermine those facts is key to understanding the epistemic differences between insights patients have about themselves and about the external world. (shrink)

In the monograph Philosophy and Psychedelics: Frameworks for Exceptional Experience, Hauskeller raises the important subject of individualization and alienation in psychedelic psychotherapy. Under the prevailing conditions of neoliberalism, Hauskeller contends that psychedelic-assisted psychotherapy appropriates Indigenous knowledges in an oppressive fashion, may be instrumentalised to the ends of productivity gain and symptom suppression, and may be utilised to mask societal systems of alienation. Whilst offering a valuable socio-political critique of psychedelics' clinical uptake, we suggest that Hauskeller's view does not adequately acknowledge (...) the ways in which psychedelics offer a challenge to the Western reductive bio-medical understanding of healing and wellbeing. It is contended herein that Indigenous knowledges, in alliance with a range of emerging sciences, offer both an engagement with ethnomedicines in a less harmfully appropriative fashion, and a renewed understanding of the means by which psychedelics achieve therapeutic change. With this understanding, what becomes apparent are the potential ways in which psychedelic medical usage may produce positive feedback upon the oppressive systems in which we are embedded. That is, transpersonal experience through encounters with the ineffable may offer a revisioning of Western psychology and cognitive science. Indeed, if psychedelics are approached with an understanding of the actual means by which they produce therapeutic outcomes—changing mental representations of the self, or self-insight derived through non-ordinary states of consciousness—then psychedelic psychotherapy offers a reimagining of psychiatric nosology, challenging conventional understandings of both pathology and wellbeing through an overturning of specified and discrete deficit models of psychopathology. This may provide both a critique of the prevailing categories used to describe madness and an expansion of our understanding of the mind-body relation, as well as an increased recognition of positive psychology grounded in cross-cultural contemplative traditions. This provides an implicit challenge to the pharmaceutical industrial-complex and its profit motives; and the corresponding neoliberalist, globalising tendencies which Hauskeller seeks to address. -/- . (shrink)

Questions are currently being posed concerning the implications of the clinical uptake of psychedelics. While enthusiasm surrounds the potential therapeutic benefits of psychedelics and critique surrounds their appropriation to commercial ends, limited attention has been given to the role of psychedelics in generating social transformation. Herbert Marcuse contended radical change requires ‘new imaginaries of liberation’. We consider whether clinical uptake of psychedelics may produce the perceptual shifts necessary to generate social transformation surrounding contemporary alienating conditions. Economic structures contributing to these (...) alienating conditions are highly resistant to change and may neuter psychedelics’ revolutionary potential. We illustrate how psychedelics may be instrumentalised: regulating individuals into unjust systems; redirecting psychedelic usage away from therapeutic ends towards productivity; distracting or diverting attention from systemic forms of control; usurping non- ordinary states into the domain of self-care; and fetishistically commodifying psychedelic experience as a consumable. There are, however, reasons to believe that psychedelics, in raising consciousnesses, may prove resistant to co-option. In particular, psychedelics induce perceptual experiences that: challenge the paradigmatic assumptions of industrial society by provoking alternative epistemologies and meta- physics; generate expanded or ecological constructions of selfhood, thereby offering resignifications of meanings, desires, and life potentials; and offer the enriched phenomenological insight into self, other, and world called for in combating ubiquitous social alienation. In this way, psychedelics may induce the revolution in perception necessary to imagine liberatory potentials and spark the desire for collective emancipation. (shrink)

In this opinion piece we propose the investigation of psychedelic-assisted psychotherapy for the treatment of body dysmorphic disorder (BDD). BDD is a psychiatric disorder characterised by appearance-based preoccupations and accompanying compulsions. While safe and effective treatments for BDD exist, non-response and relapse rates remain high. Therefore, there is a need to investigate promising new treatment options for this highly debilitating condition. Preliminary evidence suggests safety, feasibility, and potential efficacy of psychedelic treatments in disorders that share similar psychopathological mechanisms with BDD. (...) Drawing on this evidence, as well as on relevant qualitative reports and theoretical proposals, we argue that it would be worthwhile to conduct a phase 2a study aimed at assessing the safety and feasibility of psychedelic-assisted psychotherapy in BDD. We also offer some suggestions for how future research ought to proceed. (shrink)