A powerful case for why anthropology should study outsiders of thought and their speculative ideas  What sort of thinking is needed to study anomalies in thought? In this trenchantly argued and beautifully written book, anthropologist Peter Skafish explores this provocative question by examining the writings of the medium and “rough metaphysician” Jane Roberts (1929–1984). Through a close interpretation of her own published texts as well as those she understood herself to have dictated for her cohort of channeled personalities-including one, named “Seth,” who would inspire the New Age movement-Skafish shows her intuitive and dreamlike work to be a source of rigorously inventive ideas about science, ontology, translation, and pluralism. Arguing that Roberts’s writings contain philosophies ahead of their time, he also asks: How might our understanding of speculative thinking change if we consider the way untrained writers, occult visionaries, and their counterparts in other cultural traditions undertake it? What can outsider thinkers teach us about the limitations of even our most critical intellectual habits?Rough Metaphysics is at once an ethnography of the books of a strange and yet remarkable writer, a commentary on the unlikely philosophy contained in them, and a call for a new way of doing (and undoing) philosophy through anthropology, and vice versa. In guiding the reader through Roberts’s often hallucinatory “world of concepts,” Skafish also develops a series of original interpretations of thinkers-from William James to Claude LÉvi-Strauss to Paul Feyerabend-who have been vital to anthropologists and their fellow travelers. Seductively written and surprising in its turns of thought, Rough Metaphysics is a feast for anyone who wants to learn how to think something new, especially about thought.