Neuroscience has made considerable progress in figuring out how the brain works. We know much about the molecular-genetic and biochemical underpinnings of sensory and motor functions, and recent neuroimaging work has opened the door to investigating the neural underpinnings of higher-ordercognitive functions, such as memory, attention, and even free will. In these types of investigations, researchers apply specific stimuli to induce neural activity in the brain and look for the function in question. However, there may be more to the brain and its neuronal states than the changes inactivity we induce by applying particular external stimuli. In Volume 1 of Unlocking the Brain, Coding, Georg Northoff presents his argument for how the brain must code the relationship between its resting state activity and stimulus-induced activity in order to enable and predispose mental states and consciousness. In Volume 2, Consciousness, Georg Northoffaddresses consciousness by hypothesizing about the relationship between particular neuronal mechanisms and the various phenomenal features of consciousness.