Discuss the theme of Justice and mercy in Measure for Measure?

Measure for Measure has been described as a drama of ideas. Several themes can be traced in it. The theme of justice and mercy is certainly among the leading ideas in the play. This theme is clearly presented in the very opening scene of the play. Here we find that the Duke delegates his authority to Angelo. He reminds him--

 "Mortality and mercy in Vienna Live in thy tongue, and heart."

In this respect, he means to say that he is endowing Angelo with the authority to sentence a man to death if his crime calls for this punishment. He has also the authority to show mercy to a man if Angelo believes that an accused deserves mercy. Therefore, we find the workings of both justice and mercy in the play. Angelo's sentence of death against Claudio is an act of justice. Angelo is reputed to be particularly free from carnal desires. He is regarded as a Puritan and as a man who observes very strict standards of conduct. As soon as the Duke has left, Angelo begins his work of administering the country with an iron hand. He proclaims that all the brothels in the suburbs of Vienna would be dismantled and that prostitution in the suburbs would be banned with immediate effect. But Angelo is determined to put a stop to all criminal activities. Here strict justice of Angelo is obvious. Claudio has been found guilty of fornication. He had been living with a girl called Juliet without having married her. Of course, Claudio had a strong reason for not having married the girl. But Juliet becomes pregnant by Claudio. According to the law, Claudio will bear the penalty of death. Now, Angelo wants to give the death sentence to Claudio. He does not show any mercy to Claudio. On the other hand, Escalus is a merciful and humane judge by nature and temperament. On coming to know that Angelo has sentenced Claudio to death, Escalus pleads on Claudio's behalf and asks Angelo to pardon Claudio's life. Then comes Isabella's intervention in the case. Her first interview with Angelo has been described as a contention of justice and mercy. Angelo represents the demands of Justice, while Isabelle represents the desirability and the need for mercy. The Duke's conduct throughout the play shows the compassion which is inherent in him. Mercy dominates his nature. The Duke's judgments in Act-V are characterized more by mercy than by a strict regard for justice. The Duke deals almost in the same manner with Lucio also. Lucio is a dissolute young man who has been haunting brothels and who has made a girl pregnant after having falsely promised to marry her. Now, Lucio is the one person whom the Duke finds impossible to forgive. Accordingly, the Duke orders him first to marry the mother of his illegitimate child, and then to be whipped and hanged. However, in this case, also the Duke forgives Lucio. Thus at the end of the play, we find that justice is not only tempered with mercy but is considerably diluted by mercy. We can even say that the play shows the triumph of mercy over justice. Mercy undoubtedly has an important role in determining the fate of the various characters in Measure for Measure. Here there are scenes in which justice predominates, and there are scenes in which mercy predominates. In the end, mercy has proved to be the predominating force.