火攻

The five fire targets (火人、火積、火輜、火庫、火隊) represent a systematic classification of incendiary warfare. 火人 targets enemy soldiers in their encampments; 火積 targets accumulated grain and provisions; 火輜 targets supply wagons and logistics; 火庫 targets weapons depots and storehouses; 火隊 targets troop formations in the field or their lines of communication.

箕 (Ji), 壁 (Bi), 翼 (Yi), and 軫 (Zhen) are four of the twenty-eight lunar mansions (二十八宿) in Chinese astronomy. Traditional military theory held that when the moon occupied these positions, dry winds were likely. This reflects the integration of astronomical observation into ancient Chinese military planning.

行火必有因: 因 here means 'conditions' or 'agents' — some commentators read it as requiring human agents (inside men to start the fires), others as requiring favourable conditions. The translation preserves the ambiguity.

The tactical sequence is precise: fire is the disruptive weapon, the conventional assault is the decisive blow. Fire without follow-up wastes the opportunity; assault without the fire's disruption wastes lives.

以數守之: 數 here means 'calculations' or 'numerical principles' — the army must have systematic rules for when and how to employ fire, not act on impulse. Some commentators read 數 as referring specifically to the astronomical calculations for timing.

水可以絕，不可以奪: 絕 means to sever or cut off (isolating enemy forces by flooding), while 奪 means to seize or destroy (as fire does to supplies). Water is a tool of separation; fire is a tool of destruction.

費留 is a rare compound. 費 means 'waste' or 'expense'; 留 means 'to linger' or 'to stall.' The term describes a situation where military success is squandered because the victor fails to exploit or consolidate gains — burning resources without strategic follow-through.

This closing passage shifts dramatically from the technical discussion of fire attacks to a profound meditation on the irreversibility of war. Many commentators consider it the moral climax of the entire Sunzi. The transition from incendiary tactics to philosophical restraint is deliberate: the chapter on the most destructive weapon ends with the strongest warning against recklessness.

The line 怒可以復喜...死者不可以復生 ('Anger can turn to joy... but the dead cannot live again') is one of the most quoted passages in the Sunzi. It establishes a hierarchy of irreversibility: emotions are reversible, but the consequences of war are not. This argument against wars of passion underpins much of classical Chinese strategic thought.

Some editions place this closing section as a separate passage, arguing it is a general coda to the text rather than specific to fire attacks. The Eleven Commentators tradition keeps it within chapter 12, and it reads naturally as a warning that the most destructive capabilities demand the greatest restraint.