Portia, in Shakespeare's play The Merchant of Venice, pays two very different roles. First, her role is that of a daughter who must live by the vow made to her father regarding her inheritance and her marriage. She is not allowed the rights to her inheritance unless her husband has been able to solve the puzzle of the three boxes. Second, Portia plays Balthazar--a man who appears in court in order to help Antonio (in a case brought forth by Shylock).
Underneath, Portia is a torn woman. Essentially, her feminine emotions allow her to fall immediately for Bassanio. She, therefore, hints at the box he must choose in order to have her hand (and her wealth). On the other hand, Portia's prowess allows her to be very successful in the courtroom. (Something men would not believe a woman capable of). In the end, she seems torn based upon her female emotions and her male ambition.)
Her role, in the end, is one which is meant to highlight both the emotion and cognitive power of a woman. Unfortunately, at this point in time, women were not deemed as highly as men. The fact that Portia, a woman, is able to sway the courts is important.
Portia has two roles in this play. The first is to marry, the typical role for a woman in her time period. This role shows just how constricted even a wealthy woman's lot could be. Portia has no choice in who she marries, as her controlling father has set up circumstances so that her future husband must correctly choose one of three caskets in order to win Portia's hand and fortune. She laments, no doubt articulating the woes of many women at the time, "O me, the word 'choose!' I may neither choose whom I would nor refuse whom I dislike."
But Portia is not the stereotypical passive woman, accepting her lot: she knows she wants to marry Bassanio. Therefore, she sets it up so that music plays to convey clues about which box he should pick.
Portia's other, more unconventional role, is to play a lawyer and defend Antonio. Since a woman wasn't actually allowed to be a lawyer, she disguises herself as a man—and does an admirable job defending her client. Her famous speech, "The quality of mercy is not strained," merges the pathos—the appeal to emotions, to our better instincts—that we associate with the stereotypically feminine and the intelligence we associate with a man. She saves Antonio, and both Antonio and Bassanio end up indebted to her. Could Shakespeare be suggesting through Portia that the constricting roles his society imposed on women don't make sense, and that women are capable of as much intelligence and agency as men?