Set and setting: The missing factors in Chris Letheby’s psychedelic philosophy
South African Journal of Philosophy September 11, 2025 Peer reviewed DOI: 10.1080/02580136.2025.2536956 via Semantic Scholar
Summary
Chris Letheby's two-factor account of psychedelic therapy highlights plasticity induction and new self-modelling reinforced during integration, but overlooks non-individualistic aspects. This article argues that "set and setting"—embodiment (set) and embeddedness in the environment (setting)—critically inform Letheby's theory by filling in missing phenomenological components, showing how the subject's embodied state and environmental context shape the experience's content, quality, and therapeutic value.
Study at a glance
| Design | theoretical or philosophical paper |
|---|---|
| Key finding | The principles of set and setting, encompassing embodiment and embeddedness, critically inform Letheby's two-factor account of psychedelic therapy by providing missing phenomenological components. |
Abstract
Chris Letheby offers a two-factor account of psychedelic therapy in which the first of these factors is the induction of plasticity on neural, cognitive, and phenomenological levels. The second factor, which Letheby believes is crucial for lasting change, is the discovery of new forms of self-modelling within the psychedelic experience and the appropriate reinforcement thereof in the period of integration. However, even though this theory accounts for methods of action, it neglects to mention the importance of non-individualistic aspects of the experience and its influence on the value that the psychedelic experience holds for therapy. For the psychedelic experience, this interrelatedness between the subject and its environment is classically referred to as “set and setting”. This article aims to show how the principles of set and setting may critically inform Letheby’s theory by filling in the missing phenomenological components. “Set” encapsulates the notion of embodiment, given its emphasis on the role played by the embodied subject in the act of experience, that is, how the psychedelic experience is dependent on the embodied state of the experiential subject. Likewise, embeddedness is akin to “setting”, as it accounts for the role the environment plays in the content, quality and value of the psychedelic experience.