The five relationships of Confucianism are father and son, elder brother and younger brother, husband and wife, older friend and younger friend, and ruler and subject. Confucius saw these relationships as the building blocks of a civilized society. A particular set of behaviors must be maintained in each relationship, which comes from the development of deliberate traditions. Without them, he believed humans would return to anarchy. Li is a concept within Confucianism that dictates how those who practice it should prioritize their lives. The five relationships of Confucianism fall under the concept of Li, which is based on the philosophy of Confucius that a healthy life required a structured society. To Confucius, a good ruler is benevolent, and the ruler's subjects are loyal. A father is loving to his son, and the son demonstrates reverence to his father. A husband should be good to his wife, and his wife should, in turn, be obedient. An older sibling should be gentle to younger siblings, and younger siblings should be respectful of their older siblings. Finally two friends should be considerate and respectful of each other. Based on these principles, Confucius believed it was possible to form an ideal relationship with everyone people encountered throughout their lives. The fact that three of the five relationships are familial reiterates the key role that family plays in Confucianism. Confucius says that a father must display love and kindness toward his son, while the son should display obedience and reverence toward his father. Confucius says that the husband in a marriage should behave righteously to merit humility and a respectful obedience from his wife. An elder should show consideration toward those younger than him, while a youth must display deference toward those older than him. These three relationships reflect Confucius' doctrine that the father in a family is the most important figure in a household. An older brother should be gentle with his younger brother, and the younger brother must display humility and respect toward his older brother. This reflects Confucius' teaching that the oldest son is next in line to hold authority in the house following the death of a father. Confucius also taught that a ruler has a duty to show benevolence toward his subjects and that the subjects should in turn show loyalty toward their ruler.