Measure for Measure Lesson Plan

What does the Duke's plan tell us about how the play is exploring the role of deceit in carrying out justice?

The Duke's near-constant deceptions in his pursuit of "justice" suggest that no one can pursue justice without engaging in some kind of deception. For example, there is no way, currently, for any of the characters to challenge the authority of Angelo in any meaningful way, given what we know about them. Though what Angelo is doing to Claudio is universally considered unjust, there seems to be no way to challenge it. However, the only chance they do get comes from the Duke, but it does require some deceit.

Discuss the Duke's recommendation to Claudio to...