Book excerpt: An argument for a Copernican revolution in our consideration of mental features—a shift in which the world-brain problem supersedes the mind-body problem. Philosophers have long debated the mind-body problem—whether to attribute such mental features as consciousness to mind or to body. Meanwhile, neuroscientists search for empirical answers, seeking neural correlates for consciousness, self, and free will. In this book, Georg Northoff does not propose new solutions to the mind-body problem; instead, he questions the problem itself, arguing that it is an empirically, ontologically, and conceptually implausible way to address the existence and reality of mental features. We are better off, he contends, by addressing consciousness and other mental features in terms of the relationship between world and brain; philosophers should consider the world-brain problem rather than the mind-body problem. This calls for a Copernican shift in vantage point—from within the mind or brain to beyond the brain—in our consideration of mental features. Northoff, a neuroscientist, psychiatrist, and philosopher, explains that empirical evidence suggests that the brain's spontaneous activity and its spatiotemporal structure are central to aligning and integrating the brain within the world. This spatiotemporal structure allows the brain to extend beyond itself into body and world, creating the “world-brain relation” that is central to mental features. Northoff makes his argument in empirical, ontological, and epistemic-methodological terms. He discusses current models of the brain and applies these models to recent data on neuronal features underlying consciousness and proposes the world-brain relation as the ontological predisposition for consciousness.