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