An interdisciplinary deep dive into Buddhist jhana meditation and how it can transform our understanding of self and consciousness, States of profound meditative concentration, the jhanas are central to the earliest Buddhist teachings. For centuries in Southeast Asia, oral Yogavacara (yoga practitioner) lineages kept traditional jhana practices alive, but in the nineteenth and twentieth centuries, reforms in Theravada Buddhism downplayed the importance of jhana in favor of vipassana (insight) meditation. Some began to consider the jhanas 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 jhanas, 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 Yogavacara's Manual, and findings from the first in-depth, peer-reviewed neuroscience study of jhana meditation, Dennison unpacks this ancient practice in all its nuance while posing novel questions about perception, subjectivity, and the nature of enlightenment.