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)

Serotonergic (or “classic”) psychedelics have struck many researchers as raising significant philosophical questions that, until recently, were largely unexplored by academic philosophers. This paper provides an overview of four emerging lines of research at the intersection of academic philosophy and psychedelic science that have gained considerable traction in the last decade: selfless consciousness, psychedelic epistemology, psychedelic ethics, and spiritual/religious naturalism. In this paper, we highlight philosophical questions concerning (i) psychedelics, self-consciousness, and phenomenal consciousness, (ii) the epistemic profile of the psychedelic (...) experience; (iii) ethical concerns about the appropriate use of psychedelics; and (iv) whether spiritual or religious dimensions of psychedelic use are compatible with a naturalistic worldview. (shrink)

Psychedelic ingestion and meditative practice are both ancient methods for altering consciousness that became widely known in Western society in the second half of the 20th century. Do the similarities begin and end there, or do these methods – as many have claimed over the years – share some deeper common elements? In this chapter I take a neurophilosophical approach to this question and argue that there are, indeed, deeper commonalities. Recent empirical studies show that psychedelics and meditation modulate overlapping (...) brain networks involved in the sense of self, salience, and attention; moreover, psychedelics can occasion lasting increases in “mindfulness-related capacities” for taking a non-reactive stance on one’s inner experience (e.g. Sampedro et al. 2017). The self-binding theory of psychedelic ego dissolution (Letheby and Gerrans 2017) offers a plausible explanation of these findings: by disrupting self-related beliefs implemented in high-level cortical networks, both psychedelics and meditation can “unbind” mental contents from one’s self-model, moving these contents along the continuum from phenomenal transparency to opacity (cf. Metzinger 2003). In other words, both psychedelics and meditation can expose and weaken our foundational beliefs about our own identity, allowing us to disidentify with these beliefs and see them as “just thoughts”. There are connections between these ideas and recent arguments suggesting that psychedelic use may have epistemic benefits consistent with philosophical naturalism (Letheby 2015, 2016, 2019). I conclude with a proposal: these connections may help in thinking about the putative epistemic benefits of meditation practice from a naturalistic perspective. (shrink)

Recent scientific research suggests that altered states of consciousness induced by classic psychedelic drugs can cause durable psychological benefits in both healthy and patient populations. The phenomenon of ‘psychedelic transformation’ has many philosophically provocative aspects, not least of which is the claim commonly made by psychedelic subjects that their transformation is centrally due to some kind of learning or knowledge gain. Can psychedelic experiences really be a source of knowledge? From the vantage point of philosophical materialism or naturalism, a negative (...) answer is tempting because psychedelic subjects often claim drug-facilitated knowledge of non-natural, transcendent realities. This fact, combined with common conceptions of these drugs as ‘hallucinogenic’ or ‘psychotomimetic’, invites the conclusion that claims of epistemic benefit from psychedelic experience are uniformly false. However, several recent proposals have been made in the literature about naturalistically acceptable epistemic benefits that might arise from psychedelic use. In this chapter I review these proposals, classifying them in accordance with standard epistemological categories, and discuss the arguments for and against them. I also offer some suggestions for future research. (shrink)

Neoplatonism is alive and well today. It expresses itself in New Thought and the mind-cure movements derived from it. However, to avoid many ancient errors, Neoplatonism needs to be modernized. The One is just the simple origin from which all complex things evolve. The Good, which is not the One, is the best of all possible propositions. A cosmological argument is given for the One and an ontological argument for the Good. The presence of the Good in every thing is (...) Spirit. Spirit sits in the logical center of every body; it is surrounded by the regulatory forms of that body. Striving for the Good, Spirit seeks to correct the errors in its surrounding forms. To correct the errors in biological texts, modern Neoplatonists turn to the experimental method. This Neoplatonism is pantheistic not because of some theoretical definition of God but rather because of its practical focus on the shaping of Spirit. (shrink)

In this paper we discuss the definitional problems of altered states of consciousness and their potential relevance in phenomenological investigation. We suggest that visionary states or visionary phantasy working induced by psychedelics, as extraordinary types of altered states, are appropriate subjects for phenomenological analysis. Naturally, visionary states are not quite ordinary workings of the human mind, however certain cognitive psychological and evolutionary epistemological investigations show that they can give new insights into the nature of consciousness. Furthermore, we suggest that contemporary (...) inquiries concerning altered states in consciousness studies give an opportunity to complete the contemporary phenomenological investigations of phantasy with the notion of visionary phantasy. Here we propose that the similarities and differences between Dieter Lohmar’s weak phantasy and Benny Shanon’s concept of vision are precisely discernible, and, consequently, it may be possible that weak phantasy and visionary phantasy are situated on the two outermost poles of the colorful spectrum of phantasy activity. (shrink)

Ayahuasca is a psychoactive substance from the Amazon rainforest regions of Peru, Colombia, Ecuador, and Brazil. Although its use originated among indigenous tribes in the Amazon basin, it has become increasingly popularized in Western society through the transnational markets of spirituality and religiosity driven by globalization, Postmodernity, and new forms of religious practice. In this paper, we will overview the arrival of ayahuasca in Uruguay by way of four different groups. We will then focus on one of these groups, a (...) holistic alternative therapies center, influenced by Peruvian shamanic traditions in the design of its ceremonies. Last we will introduce a “distributed cognition” model to explain ayahuasca rituals as a system of activity. (shrink)