An overview and critical analysis of the study of consciousness, integrating findings from philosophy, psychology, and cognitive neuroscience into a unified theoretical framework. The question of consciousness is perhaps the most significant problem still unsolved by science. In Inner Presence, Antti Revonsuo proposes a novel approach to the study of consciousness that integrates findings from philosophy, psychology, and cognitive neuroscience into a coherent theoretical framework. Arguing that any fruitful scientific approach to the problem must consider both the subjective psychological reality of consciousness and the objective neurobiological reality, Revonsuo proposes that the best strategy for discovering the connection between these two realities is one of "biological realism," using tools of the empirical biological sciences. This approach, which he calls the "biological research program," provides a theoretical and philosophical foundation that contemporary study of consciousness lacks. Revonsuo coins the term "world simulation metaphor" and uses this metaphor to develop a powerful way of thinking about consciousness as a biological system in the brain. This leads him to propose that the dreaming brain and visual consciousness are ideal model systems for empirical consciousness research. He offers a comprehensive overview and critical analysis of consciousness research and defends his approach against currently popular philosophical views, in particular against approaches that deny or externalize phenomenal consciousness, or claim that brain activity is not sufficient for consciousness. He systematically examines the principal issues in the science of consciousness--the contents of consciousness, the unity of consciousness and the binding problem, the explanatory gap and the neural correlates of consciousness, and the causal powers and function of consciousness. Revonsuo draws together empirical data from a wide variety of sources, including dream research, brain imaging, neuropsychology, and evolutionary psychology, into the theoretical framework of the biological research program, thus pointing the way toward a unified biological science of consciousness. Applying imaginative thought experiments, Inner Presence reaches beyond the current state-of-the-art, revealing how the problem of consciousness may eventually be solved by future science.