Dennett has remarked in several places (such as "Self-portrait", in "Brainchildren") that his overall philosophical project has remained largely the same since his time at Oxford. He is primarily concerned with providing a philosophy of mind that is grounded in empirical research. In his original dissertation, "Content and Consciousness", he broke up the problem of explaining the mind into the need for a theory of content and for a theory of consciousness. His approach to this project has also stayed true to this distinction. Just as "Content and Consciousness" has a bipartite structure, he similarly divided "Brainstorms" into two sections. He would later collect several essays on content in "The Intentional Stance" and synthesize his views on consciousness into a unified theory in "Consciousness Explained". These volumes respectively form the most extensive development of his views.