Our conscious inner life is characterized by subjective experiences that manifest themselves in a huge variety of phenomenal qualities: the enticing scent of a rose, the taste of a fresh strawberry, or the moment of happiness while viewing a colorful sunset, to name a few typical examples. Even though no one doubts that the brain is involved in the formation of such phenomenal states, the specific role of the brain in conscious processes is the subject of intense scientific debate. To unveil the mechanism behind conscious processes, new conceptual approaches are required, which is why the understanding of consciousness is considered to be one of the greatest scientific challenges of the 21st century. In particular, it will be important to find out whether consciousness is a fundamental property of the universe, how consciousness can be coherently integrated into our physical worldview, and what distinguishes conscious systems from nonconscious systems. These questions give this field of research its unique appeal.