The main theme of John Eccles’s lecture is to demonstrate the wide explanatory power of dualist-interactionism in contrast to the inadequacy of all varieties of the materialist theories of mind. There is critical discussion in the first chapter on the materialist hypotheses of the relationship of the self-conscious mind to the brain. The subsequent chapters further the strong dualist-interactionism developed in Eccles’s previous work, The Self and Its Brain, exploring the relations to a wide variety of phenomenon relating to self-consciousness. The final four chapters demonstrate that dualist-interactionism offers valuable insights into the higher levels of human experience, which cannot be accommodated to the materialist theories of the mind. Eccles’s exploration of the brain-mind relationship is based on the scientific study of the brain, both its structure and its physiological performance. Overall, his theme develops more philosophical overtones in relation to such topics as creativity, altruism, pseudaltruism, aggression and values. Finally, considerations regarding the purpose and meaning of self-conscious life lead to the pinnacle in the unifying concepts of the human psyche and its status in relation to God.