Discipline is the assertion of willpower over more base desires, and is usually understood to be synonymous with self control. Self-discipline is to some extent a substitute for motivation, when one uses reason to determine the best course of action that opposes one's desires. Virtuous behavior is when one's motivations are aligned with one's reasoned aims: to do what one knows is best and to do it gladly. Continent behavior, on the other hand, is when one does what one knows is best, but must do it by opposing one's motivations.  Moving from continent to virtuous behavior requires training and some self-discipline.
1. the practice of training people to obey rules or a code of behavior, using punishment to correct disobedience.
2. a branch of knowledge, typically one studied in higher education.
1. train (someone) to obey rules or a code of behavior, using punishment to correct disobedience.