The Methods of the Sima (simplified Chinese: 司马法; traditional Chinese: 司馬法; pinyin: Sīmǎ Fǎ, also known as The Marshal's Art of War) is a text discussing laws, regulations, government policies, military organization, military administration, discipline, basic values, tactics, and strategy. It is considered to be one of the Seven Military Classics of ancient China. It was developed in the state of Qi during the 4th century BC, in the mid-Warring States period.
In the East Han dynasty, The Methods of the Sima was classified as a work describing rites and propriety (禮), largely because it discusses methods of organization, administration, and discipline much more deeply than strategy or battlefield tactics. The Methods of the Sima rarely discusses direct issues related to battlefield command, instead concerning itself with how to initiate, administer, and manage military campaigns. The limited discussions of strategy and tactics which do appear in the work are broad, general, and common to the other Seven Military Classics. The text emphasizes ritual differentiation between the military and civil realms (wen and wu), and marks complimentarity of the two (e.g. 天子之義 chapter, 文與武左右也).
The Methods of the Sima promotes the view that warfare is necessary to the existence of the state, that it provides the principal means for punishing evil and rescuing the oppressed, and that its conscientious exploitation is the foundation for political power. It states that a balance between war and peace must be maintained for the prosperity of the state: that those states which neglect their armies will perish just as quickly as those states which resort to warfare too frequently. The book promotes the view that war is an unfortunate necessary for peace.
The contributors to the Methods of the Sima stress that appropriate civil and military roles must be distinguished because of their contradictory values. Civilian culture is judged to be severe, remote, and languid, placing value in courtesy and benevolence, while military culture is judged to be severe, stern, and active, placing value in order and discipline. The writers of the Methods stress that the Virtue (德) of the people will decline both when civilians act in ways that are appropriate for soldiers, and when soldiers act in ways that are appropriate for civilians. The King must conduct himself differently in these two spheres and expect different things from his citizens. In civil life, he must cultivate the people through education and the promotion of regional culture.