Yijing rules of warfare

The Yijing rules of warfare make legitimacy, disciplined conduct, and unified command conditions of a successful expedition. The commentary on Hexagram Sze, or Hosts, distinguishes a rightful campaign against rebellion and plunder from an improperly conducted war: the army must set out according to rules, answer to a trusted commander, and resist competing claims to authority. The work’s larger political frame connects that standard to the collapse of public order under the Shang and to the argument that force is justified when used by rightful authority to suppress disorder.

The Political Problem of War

The rules emerge in an account of a kingdom described as disorganized and demoralized. The people, great and small, are said to engage in robbery and treachery; nobles and officials violate the laws, criminals evade apprehension, and ordinary people commit violent outrages against one another. The account compares the dynasty’s condition to crossing a large stream without finding either ford or bank: the problem is not merely a threat to the throne but a general failure of order and security.

The narrative attributes much of this crisis to the monarch’s conduct. Its denunciation presents a ruler who disregards virtue, alienates the people, neglects laws and sacrifices, and entrusts honor and confidence to bad officials. This portrayal supplies a political context for the rules of warfare: the case for force rests on the disorder to be remedied and the authority under which the remedy is undertaken, not on military strength by itself.

Purpose and Conduct

In the commentary on the first line of Hexagram Sze, the army’s departure must accord with rules; if those rules are not good, the outcome will be bad. The text does not specify exactly what the rules are. Its commentator records two readings: they may refer to reasons that justify the campaign, such as repressing and punishing disorder and rebellion, or, more plausibly in his view, to the discipline and procedures the troops must observe. A footnote makes the principle explicitly twofold: both the war’s end and the manner of conducting it, especially at the outset, must be right.

The fifth line gives the rule a sharper limit. Its image of birds in the fields is interpreted as plunderers or invaders whom it is advantageous to destroy. The accompanying commentary reads this as support for defensive war, or for war undertaken by rightful authority to put down rebellion and lawlessness. The image therefore does not license force without distinction: it identifies an aggressor whose predatory action gives the campaign its stated defensive purpose.

Command and Unity

The campaign’s legitimacy also depends on who leads it and whether that authority is secure. Hexagram Sze places the strong line in the second position, which the commentary identifies with the general. The divided line in the fifth, royal position responds to him, signifying the sovereign’s confidence in the commander. A footnote explains that the king’s orders, described as conveyed three times, indicate an appointment entrusted exclusively to the general, not repeated appointments or rewards bestowed after the fact.

The third line warns against allowing several commanders to share power. Its subject is represented as overstepping the appointed leader and seeking a share of his command and honor. The commentary calls the result divided authority and predicts evil: a campaign cannot follow the rule of a single, trusted commander if subordinate figures compete for control. The point is institutional as well as personal; the army’s conduct depends on an intelligible chain of command.

The fifth-line interpretation reinforces that structure through the contrast between the chief authority and the general. The king is described as weak or humble and as ceding the power to execute judgment to the commander-in-chief, represented by the second line. The oldest son leads the host; younger men, associated with the third and fourth lines, must not be admitted to share his command. The rule is not that sovereign authority disappears, but that it entrusts execution to one appointed leader rather than fragmenting it among rivals.

Appointment and Political Aftermath

The final line carries the principle of controlled authority beyond the battlefield. The ruler distributes charges to those who have distinguished themselves, appointing some as rulers of states and others as chiefs of clans; small men, however, should not be placed in those positions. The commentary regards this as an important lesson, even while noting that critics have difficulty deriving it from the line’s position. Military service may lead to political appointments, but the distribution of authority must remain selective and attentive to the character of those entrusted with it.

These rules are presented through Hexagram Sze, whose name can mean both Hosts and multitudes. Its commentary connects the population of a feudal kingdom with the army it may become when required, making the organization of military force a matter of public and political order. The resulting standard is conditional rather than celebratory: force is justified by a rightful purpose, constrained by proper conduct, directed through trusted and unified command, and followed by careful decisions about who receives authority.