The Duke of Vienna speaks with a nobleman, Escalus, about his plan to leave another nobleman, Lord Angelo, in charge of the city while the Duke travels. Angelo is summoned and informed of this plan, and he requests that the Duke test him first with a smaller responsibility. The Duke ignores Angelo's request—the executive decision has already been made, and the Duke will leave town shortly.
Angelo’s hesitance to accept the role of interim leader suggests he doesn’t trust himself. Perhaps Angelo is conscious of his shortcomings, and doesn’t want the power—or liberty—to be able to cause harm. This responsible attitude does not excuse Angelo’s egregious hypocrisy later in the play, but it does cast him as a relatively sympathetic villain. Just as important, the Duke’s refusal to listen makes him in part responsible for what happens under Angelo’s rule.
The Duke leaves, saying he does not enjoy the formal, public aspects of his authority. Afterwards, Escalus requests that Angelo listen to his input while he oversees the city.
The Duke’s remarks characterize him as a humble and well-intentioned leader, more concerned with the welfare of his state than with his symbolic public stature. In other words, he is less preoccupied with the appearance of being a ruler, but rather with the substance of ruling well.