vow

The explicit marital promise Jiang treats as the real object violated by cheating.

Jiang says the greatest gift God gives is free will, so a vow that surrenders free will to God is uniquely serious and cannot be casually compensated for after it is broken.

Jiang introduces a hypothetical scenario in which Piccarda's brother vows to give her as a bride after a military victory, setting up a clash between two vows to God rather than asserting this exact sequence as settled history.

Jiang turns Piccarda's dilemma into a direct clash of vows by having her threaten suicide rather than break her vow to God while her brother insists that his victory in battle binds him to give her to his friend.

Jiang says the brother cannot simply save Piccarda from an immediate suicide threat, so he escalates to threatening their mother in order to force surrender.

Jiang treats the vow as person-specific: the brother cannot substitute another woman because he explicitly promised Piccarda to his ally before the battle.

The monk hypothetical sharpens the lecture's central problem: whether devotion can force someone to violate an absolute vow in order to prevent a greater metaphysical catastrophe.

The student's challenge identifies the danger in Jiang's earlier line: if conscience alone is enough, then Piccarda or the monk could treat sincere self-justification as moral absolution.

A student states the conventional doctrinal reading that the lowest sphere houses people who broke vows, no matter how coercion occurred.