Portia is the romantic heroine of the play, and she is much with beauty and intelligence. Of her beauty, we need no convincing. Bassanio's words are enough; thus we turn to her love for Bassanio. Already she has given him cause to think that it is possible that he can woo and win her, for on an earlier visit to Belmont, Bassanio did "receive fair speechless messages" from her eyes. And when Nerissa mentions the fact that Bassanio might possibly be a suitor, Portia tries to disguise her anxiety, but she fails. Nerissa understands her mistress. Portia is usually very self-controlled, but she reveals her anxiety concerning Bassanio a little later when he has arrived at her mansion and is about to choose one of the caskets. She has fallen in love with him, and her anxiety and confusion undo her. "Pause a day or two," she begs, for "in choosing wrong, / I lose your company." She thus makes sure that he knows that it is not hate that she feels for him.
Bassanio's correct choice of the casket overwhelms Portia. She wishes she had more of everything to give Bassanio: "This house, these servants and this same myself / Are yours, my lord: I give them with this ring." She willingly shares all she owns with Bassanio. Once master of her emotions, she has fallen completely under the spell of love's madness. Love is a reciprocal giving and receiving, and so it is with perfect empathy that she sends her beloved away almost immediately to try and save his friend Antonio. They will be married, but their love will not be consummated until his friend is saved, if possible.
Portia's second characteristic that is most readily apparent is her graciousness — that is, her tact and sympathy. Despite her real feelings about the Prince of Morocco, Portia answers him politely and reassuringly. Since the irony of her words is not apparent to him, his feelings are spared. She tells him that he is "as fair / As any comer I have look'd on yet / For my affection." She shows Morocco the honor his rank deserves. But once he is gone, she reveals that she did not like him. "A gentle riddance," she says; "Draw the curtains."
When the Prince of Arragon arrives, Portia carefully addresses him with all the deference due his position. She calls him "noble." But after he has failed and has left, she cries out, "O, these deliberate fools!" To her, both of these men are shallow and greedy and self-centered; yet to their faces, she is as ladylike as possible. Lorenzo appreciates this gentle generosity of spirit; when Portia has allowed her new husband to leave to try and help his best friend out of his difficulty, he says to her: "You have a noble and a true conceit / Of god-like amity."
In the courtroom, Portia (in disguise) speaks to Shylock about mercy, but this is not merely an attempt to stall; she truly means what she says. It is an eloquent appeal she makes. Her request for mercy comes from her habitual goodness. She hopes, of course, to soften his heart, knowing the outcome if he refuses. But the words come from her heart, honestly and openly and naturally.
Finally, of course, what we most remember about Portia, after the play is over, is her wit and her playfulness. Even when Portia is complaining to Nerissa about the terms of her father's will, she does so wittily: "Is it not hard, Nerissa, that I cannot choose one nor refuse none?" And then she ticks off, like a computer, the eccentricities of the six suitors who have arrived at Belmont to try for her hand. They are either childish, humorless, volatile, ignorant, too fantastically dressed, weak, or have a drinking problem. She is clearly glad to be rid of them all when it is announced that they are departing.
We recall too the humorous way that she imagines dressing like a man and aping the mannerisms of all of the men she has observed in her short life. She bets Nerissa that she can out-man any man when it comes to swaggering and playing the macho bit: "I have within my mind / A thousand raw tricks of these bragging Jacks, / Which I will practise." Men are as transparent as stale beer to her; she revels in turning the tables and having a bit of fun even while she is on a daring mission to try and save Antonio's life. And even in the courtroom, when Bassanio extravagantly offers his life for Antonio's, Portia quips in an aside that "Your wife would give you little thanks for that, / If she were by, to hear you make the offer."
The entire ring plot is Portia's idea, and she and Nerissa relish the prospect of the jest at their husbands' expense. Bassanio swears over and over that he never gave his ring away to another woman (and he is more than a little embarrassed to admit that he gave it to another man), but with a fine sense of comedy, Portia plays the role of the "angry wife" just as well as she played the role of the "learned young lawyer" at Antonio's trial.