# Psychedelics Favour Understanding Rather Than Knowledge **Keywords:** Psychedelics ∙ Philosophy ∙ Epistemology ∙ Understanding ∙ Knowledge ∙ REBUS model ∙ Process of discovery ∙ Process of justification ∙ Epistemic benefits ∙ Epistemic Standards **Abstract:** 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. Building on the distinction between processes of discovery and processes of justification, I aim to criticise some aspects of Letheby’s epistemology of psychedelics. Unarguably, psychedelics can trigger processes of discovery. Yet, I hold, they can hardly contribute either to the epistemic success (i.e., truth, veridicality, aptness, skillfulness, etc.) 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, largely independent of the influences 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 provides a broader picture because it covers also cases of comforting delusions or placebo insights where truth and justification are lacking. **Authors:** [[Sascha Benjamin Fink]]