Thou shalt not kill

Thou shalt not kill is a Christian prohibition that becomes a practical moral boundary for John Blackthorne: he will not strangle an unarmed samurai who asks him to do so. The commandment also enters the political story through Kasigi Omi’s recollection of his former teacher, who described Christian teachings about sacred life and love as weaknesses that could be used against their adherents.

Christian Teaching and Omi’s Recollection

Omi traces his knowledge of Christianity to Jiro, a monk who had once been an apprentice Christian priest. Jiro taught him that the religion was vulnerable because it instructed people to love one another and treated life as sacred, including through the commandment Thou shalt not kill. Omi presents these principles as teachings that omit honor and duty; this is his remembered account of Jiro’s lesson, not a neutral description of Christian belief.

Omi applies that account to the unfamiliar Christians among the foreigners. He reasons that they may belong to a different Christian sect, much as Buddhist sects oppose one another, and imagines that their leader might be controlled by threatening the life of one of his men. The commandment thus appears in two sharply different registers: for Blackthorne, it forbids a particular act; in Omi’s political calculation, it offers leverage over people presumed to obey it.

Blackthorne’s Refusal

The commandment is tested when a samurai, still kneeling and wearing a shredded kimono, wraps his sash around his neck and gives one end to Blackthorne and the other to Sonk. He bows his head and motions for them to pull. Sonk understands the gesture as fear that they will strangle him, but Blackthorne recognizes that the samurai appears to be asking them to kill him.

Blackthorne lets the sash fall and refuses. He cannot explain the full distinction to a man who does not speak his language: that he will not murder or execute an unarmed man, and that suicide is condemned before God. Instead, he repeats a single word, trying to communicate that the act is forbidden. When the samurai asks again, Blackthorne again declines to pull the sash tight.

The refusal does not end the crisis. The samurai suddenly rises and plunges his head into a latrine bucket, trying to drown himself. Jan Roper and Sonk pull him out, choking and struggling; Blackthorne then orders them to let him go and indicates the bucket. His conduct draws a line between killing the man himself and allowing the man to act upon his own desire to die. The scene leaves that boundary stark: Blackthorne will not make himself the executioner, even as his final gesture does not prevent the samurai from attempting suicide.

Moral Limit and Political Vulnerability

The episode gives the prohibition an immediate bodily consequence: a sash is offered as an instrument of death, and Blackthorne refuses to use it. His refusal is not based on an ability to persuade the samurai or make the principle understood across their language barrier. It rests on the limit Blackthorne recognizes in his own conduct: he will not kill an unarmed man, and he regards suicide as damnable before God.

Set beside Omi’s account, the scene also shows how the same teaching can be read as an ethical restraint or as a strategic weakness. Omi’s remembered lesson turns the sanctity of life into a possible means of control; Blackthorne’s response makes the commandment a limit on what he will do, even in a confusing encounter where the samurai repeatedly seeks death. The text keeps those uses in tension rather than resolving them into a shared understanding.