On the need for a natural philosophy of psychedelics

‘On the need for a natural philosophy of psychedelics’ provides a brief overview of the history of psychedelics in science and psychiatry, and a detailed review of recent evidence for their therapeutic and transformative efficacy. The chapter reviews clinical trials showing that one or two controlled psychedelic experiences can durably reduce symptoms of anxiety, depression, and addiction, and can cause lasting psychological benefits in healthy subjects. The chapter also reviews evidence that these beneficial effects are mediated by the occurrence of ‘mystical-type’ experiences. This evidence gives rise to the Comforting Delusion Objection that is the central focus of the book. Existing responses involve (i) rejecting philosophical naturalism, or (ii) downplaying the importance of epistemic factors in the evaluation of psychiatric treatments. The chapter raises problems for both approaches, and outlines a new one: to show that the Objection fails even if naturalism is true and the epistemic status of psychedelic therapy is important.