The most important scientific discovery of the present era will come when someone -- or some group -- discovers the answer to the following question: How exactly do neurobiological processes in the brain cause consciousness? This is the most important question facing us in the biological sciences, yet it is frequently evaded, and frequently misunderstood when not evaded. In order to clear the way for an understanding of this problem. I am going to begin to answer four questions: 1. What (...) is consciousness? 2. What is the relation of consciousness to the brain? 3. What are some of the features that an empirical theory of consciousness should try to explain? 4. What are some common mistakes to avoid? (shrink)