Panpsychism is the philosophical view that consciousness, mentality, or 'mindedness' in some form is fundamental in the universe. The idea has existed for centuries, but only recently has it had a serious resurgence. Galen Strawson has been on the front line of the battlefield on the topic of panpsychism since the 1990s. His paper on ‘realistic monism’, contained in this volume and originally published in 2006, is now considered something of a classic and a catalyst for panpsychism’s recent revival. This long overdue new edition of the book gives the original commentators, where they feel they have something more to add, an opportunity to update their thinking on the topic of panpsychism in general and Strawson’s realistic monism in particular. Seven new postscripts are included, which aim to enhance the original collection and push the discussion onwards. Eighteen years have passed since the first edition of this groundbreaking volume, and Strawson remains a distinctive and important voice in the field — the new edition is a must-read for all who are interested in consciousness studies.