Although it is highly unlikely that we will ever "know everything," is there even a niche subject where we can possibly eliminate uncertainty? Also, more specific to Professor Firestein's field of research, how can we ever be certain of a cause and effect relationship in something like the brain? It seems like there is an infinite set of external factors that we cannot control. How certain are we about the knowledge we have about the brain and is it possible that the information we have may be as inaccurate as a predictive system like phrenology?