The purpose of this paper is to clarify the significance of the teaching of discipline for the formation of self-discipline. This is done by looking at recent teaching trends for discipline, namely the historical study of the German word Disziplin by Korn, a German educationalist. Korn, stating that the term Disziplin derives from the Latin word disciplina, pointed out that the term represents the unity of the subject and the conduct of learners. While Disziplin was previously understood as a conduct such as control, and Korn now states that the meaning of Disziplin denotes the separation of the subject from the conduct of the learners. To understand Disziplin as a unified meaning, Korn reconstructed the teaching of Disziplin by means of Hönigswald and Petzelt’s educational theory. Furthermore, the significance of his concept is to reconstruct the teaching of discipline by means of historical study and to indicate the possibilities of rethinking the current situation regarding discipline such as “zero-tolerance policing” and so on. However, Korn’s concept is problematic in that it does not focus on the subject.