This volume, with contributions from eight scholars, examines the centrality of dharmadhatu and related expressions of ultimate truth within Mahayana Buddhism, analyzing them as distinct yet interconnected concepts. Through historical and philosophical inquiry, it explores their roles in addressing conceptual dichotomies such as samsara and nirvana, conditioned and unconditioned dharmas, and traces the development of these ideas across Indian and Chinese Buddhist traditions. Engaging with key sutras and commentarial texts, the study examines dharmadhatu and other truth expressions separately, while highlighting the shared threads that connect them. The analysis reveals the doctrinal implications of these concepts and their relevance within broader Buddhist frameworks. Concise and accessible, this work offers a fresh perspective on the complexity of Buddhist thought, providing readers with a nuanced understanding of these foundational concepts and their historical trajectories.