An interdisciplinary deep dive into Buddhist jh #257;na meditation and how it can transform our understanding of self and consciousness States of profound meditative concentration, the jh #257;nas are central to the earliest Buddhist teachings. For centuries in Southeast Asia, oral yog #257;vacara (yoga practitioner) lineages kept traditional jh #257;na practices alive, but in the nineteenth and twentieth centuries, reforms in Therav #257;da Buddhism downplayed the importance of jh #257;na in favor of vipassan #257; (insight) meditation. Some began to consider the jh #257;nas to be strictly the domain of monastics, unattainable in the context of modern lay life. In recent years, however, there has been a resurgence of interest in the jh #257;nas, and as researcher Paul Dennison shows, the esoteric and sometimes "magical" pre-reform practices of Southeast Asia hold powerful potential for modern lay practitioners living in a more scientifically minded world. Drawing on traditional Buddhist doctrine, teachings from lesser-known meditation texts such as the Yog #257;vacara's Manual, and findings from the first in-depth, peer-reviewed neuroscience study of jh #257;na meditation, Dennison unpacks this ancient practice in all its nuance while posing novel questions about perception, subjectivity, and the nature of enlightenment.