In Consciousness and Persons: Unity and Identity, Michael Tye takes on the thorny issue of the unity of consciousness and answers these important questions: What exactly is the unity of consciousness? Can a single person have a divided consciousness? What is a single person? Tye argues that unity is a fundamental part of human consciousness -- something so basic to everyday experience that it is easy to overlook. For example, when we hear the sound of waves crashing on a beach and at the same time see a red warning flag, there is an overall unity to our experience; the sound and the red shape are presented together in our consciousness. Similarly, when we undergo a succession of thoughts as we think something through, there is an experience of succession that unifies the thoughts into a conscious whole. But, Tye shows, consciousness is not always unified. Split-brain subjects, whose corpus callosum has been severed, are usually taken to have a divided or disunified consciousness.