Changes in the higher qualities of culture (sometimes called the "Superstructure") are often linked to changes in the lower qualities of life (sometimes called the "Base"). One example is that in medieval times, people thought "honor" or duty to people with more power than them was very important. Today, in Western countries, many people see ambition (being someone who works hard for their own goals) as more important. This is because in medieval times, people worked their entire lives under lords who depended on them not only for work but for war. Today, people work for themselves more, and our society lets some people move up from being poor to being rich. In this case, what people see as good and important depends on how the rulers get value out of their workers.