Based on anthropological fieldwork on the revival of hallucinogen research as well as on the epistemic culture of neurophilosophy, this Common Knowledge guest column examines two very different philosophical engagements with psychedelic drugs. In Thomas Metzinger's evidence-based philosophy of mind, hallucinogens help to operationalize questions about the nature of consciousness. While this project contributes to the great divide between empirically enlightened moderns and tradition-oriented premoderns, Metzinger's neurophilosophical reanimation of the ancient conception of philosophy as cultura animi can build a bridge to Aldous Huxley's perennial philosophy, which has informed the psychedelic intelligentsia like no other body of thought. In the sixteenth century, the philosophia perennis grew out of a decidedly nonmodern (but not pre- or antimodern) philosophy of religion that sought to suture the historical and cultural cracks that would come to define modernity. This essay argues that neurophilosophy and ethnographic studies of consciousness cultures could function as critical correctives in a contemporary rearticulation of perennial philosophy.