If your opponent is of choleric temperament, seek to irritate him.

This line expresses a core Sunzian tactic: exploit an adversary’s psychological tendencies rather than relying solely on force. A “choleric” (quick-tempered) opponent is portrayed as vulnerable to provocation; if you can anger him, you may induce rash decisions, break discipline, or lure him into unfavorable terrain or timing. The broader strategic idea is to shape the enemy’s behavior by manipulating emotions—turning temperament into a predictable lever. Ethically, it highlights the amoral, instrumental tone often associated with The Art of War: victory comes from understanding human nature and using it to control the contest’s conditions.