Discipline

Discipline is an important idea in organizing human action, including in the family and in work. It is related to the word disciple. To discipline a child is to punish the child for bad behavior. Spanking is or was considered a method of child discipline. Self-discipline is controlling your own actions. 
Military discipline is training people to obey rules and keep order. A disciplined soldier is one who can act even while afraid for his life. A disciplined person is one who does what must be done to achieve his goals, even if it is difficult.