Double meaning in Measure for Measure

The title Measure for Measure comes from a combination of Biblical passages, that of "an eye for an eye" from Moses from the Old Testament, and the nature of mercy from Jesus from the New Testament. The Law of Justice is combined with the Law of Mercy. A law of retaliation may seem to only fit into the former, the "eye for an eye" notion, yet in the carnivalesque play Measure for Measure, where a clear perspective is lacking, retaliation may be disguised as mercy and mercy may be disguised as retaliation. This constant confusion and problematic exchange operates as a constant theme throughout the play. Is Isabella's character imprisoned or liberated because of her steadfast chastity and purity? is she saving herself or missing out on a seemingly natural impulse? Does Lucio want to enlighten her with pleasure or harm her with lust? Despite her attempts to be a chaste and pure woman, there is a brewing of sexuality beneath the surface; in fact all of that desire, all of her urges to repress sexuality carry their own air of lust, the lusting after goodness. I believe Shakespeare is trying to show that no matter what one desires, he or she desires something, whether it be sex or the absence of sex, and there is absolutely no way to do away with this natural human instinct. No amount of authoritarianism can trump a human's need to need and chaos will ultimately ensue. What works is a balanced order of law as well as a balanced amount of sexuality.