Without taking a single psychology course, ordinary people learn to understand, predict, and explain one another's actions, thoughts, and motivations. Many cognitive scientists and philosophers claim that our everyday or folk understanding of mental states constitutes a theory of mind. That theory is widely called folk psychology (sometimes commonsense psychology). The terms in which folk psychology are couched are familiar ones of "belief" and "desire," "hunger," "pain," and so forth. According to many theorists, folk psychology plays a central role.