Disrupting the individualism of much conventional psychological research into learning, this book presents a situated, practice-based understanding of learning, based on the theories of situated learning and practice architectures, conceptualising learning as ontological transformation.While accepting that learning is consequential for learners, this book explores how learning matters for and in the world. The authors present a view of learning not just in the context of the lives of learners and those around them, but as part of the dynamic and organic site-ontological processes of world-historical and ecological change. While learners may be stars in their own lives and learning, they are also living, agentic beings who are part of Earth's community of life and who respond to the changing world in ways that are consequential beyond their own lives. The book explores the place of learning from the point of view of the world as much as from the point of view of the learner. Distinctively, the book conceptualises learning as a social accomplishment and as a process that changes the worlds beyond individual learners.A groundbreaking contribution from the leading scholars in the field, this book will be of great interest to scholars, researchers, and post-graduate students of education, social science, and philosophy, and the specific fields of professional practice, practice theory, learning sciences, and sociology.