Errors of knowledge do not pose barriers to a proper cognitive process. If one is pursuing the truth, mistakes are in principle discoverable, and correctable. Only irrationality—the refusal to know—makes cognition impossible. Yet certain types of premises we hold appear resistant to change, even though we have rationally identified them as false. They (with their attendant emotions) seem to persist, obstructing cognition—and inducing guilt—despite conscientious efforts to replace them with true premises. Why? These lectures discuss the nature of such resistance and examine the difficulties in changing certain types of subconsciously ingrained premises.