The Pound of Flesh
The pound of flesh that Shylock demands from Antonio is a symbol with multiple meanings throughout the play. Most notably, the pound of flesh symbolizes Shylock's worldview, which is dominated by numerical calculations and leaves little room for emotion. The pound of flesh also symbolizes the connection between Bassanio and Antonio, as it is Bassanio's debt that Antonio would repay with his own body. Finally, the pound of flesh also symbolizes Shylock's own loss in the form of Jessica's departure. The case could be made that Shylock's fervent pursuit of the pound of flesh rather than monetary compensation is a way of recovering his own "flesh" and kin.
The Caskets
The three caskets from which suitors must choose in order to win Portia's hand symbolize a test, specifically a Christian test of one's morals. The gold casket promises to fulfill men's desires, while the silver casket promises to bestow what one deserves. These two false caskets are warnings to those who would follow fickle emotions like desire or who think that human beings are inherently deserving of God's grace. In the end it is the aesthetically unremarkable lead casket that holds the "treasure" of Portia's hand, underscoring the Christian teaching that appearances are deceiving and it is one's spirit that truly counts.
Leah's Ring
Rings are a significant motif in the play, as they are at once a symbol of monetary value and of meaningful connection. After Jessica elopes with Lorenzo, Shylock initially seems more bothered by the fact that she took his turquoise ring than that he lost his daughter. However, later in the play, Shylock explains that the ring belonged to Leah, his late wife. This is one instance in the play in which the audience's perception of Shylock might begin to shift, as he shows he is capable of sentimentality and thinking beyond wealth.
Portia's Ring
Portia's ring that she gives to Bassanio after he chooses the correct casket is a symbol of Portia's commitment to her new husband. She even announces that she and everything she owns are now his property (a common understanding of marriage in early modern England). However, as the play unfolds and Bassanio willingly parts with the ring as a token of gratitude to "Balthazar" (Portia in disguise), the ring becomes a symbol of Portia's own power in her relationship. As a wealthy woman, Portia's ring comes to signify Bassanio's own debt to her, as she is able to give him more than he could ever give her in return.
Cross-Dressing
In the play, three female characters dress as men in order to achieve their goals: Jessica, who escapes Venice dressed as a page, and Nerissa and Portia, who pretend to be an officer and a doctor in order to free Antonio. While cross-dressing was not an uncommon occurrence in Renaissance plays (indeed, female characters were themselves portrayed by boys or young men), The Merchant of Venice uses cross-dressing to comment on the nature of masculinity and male power. Portia is convinced that, after studying the ways of men, she can outwit anyone in court (a prediction that turns out to be true). As such, Portia suggests that male dominance is rooted heavily in performance rather than anything inherent to maleness itself. Just as the play warns audiences to be skeptical of appearances, it also suggests that one should be skeptical of traditional power structures by showcasing how easily they can be imitated and parodied.
