At the heart of the play is Shylock’s “Hath not a Jew” speech, an outcry driven by pathos that elicits sympathy from the reader, if not from Antonio. He says,
I am a Jew. Hath not a Jew eyes? Hath not a Jew hands, organs, dimensions, senses, affections, passions? Fed with the same food, hurt with the same weapons, subject to the same diseases, healed by the same means, warmed and cooled by the same winter and summer, as a Christian is? If you prick us, do we not bleed? If you tickle us, do we not laugh? If you poison us, do we not die? And if you wrong us, shall we not revenge?
Shylock speaks in prose rather than verse, signaling a visceral outcry of emotion. He also insistently asks questions, ultimately leaving the reader responsible for answers regarding morality. Though he begins his desperate series of questions by declaring “I am a Jew,” he quickly blurs the lines between religions, insisting on a moral code that recognizes all humans as fundamentally the same. He focuses on sensory experiences—both comforting and excruciating—in order to appeal to the common experience of all people and, moreover, to the Christian principle in the Gospel of Matthew (7:12) that “in everything, do to others what you would have them do to you.” Nevertheless, Salario and Salanio—Antonio’s representatives—are not moved by this speech, leaving them at odds with the audience and cementing the play's Christians as hard-hearted at best and, at worst, incapable of compassion.
By the end of his speech—with no sign of understanding between himself and the Christians—Shylock pivots in his approach, warning them in a statement rather than a question that Jews will respond in kind if treated cruelly:
The villainy you teach me, I will execute, and it shall go hard but I will better the instruction.
He lays the reason for his own rage at the feet of the men who have taught him how to hate. In doing so, he suggests that a willingness to see oneself in others will change the course of events; without the ability to recognize and respond sympathetically to pathos, a cycle of animosity will inevitably continue.
Portia uses pathos—appealing to an audience's emotions—in court when she is disguised as Balthazar and attempts to persuade Shylock to practice mercy and spare Antonio. She states,
The quality of mercy is not strained.
It droppeth as the gentle rain from heaven
Upon the place beneath. It is twice blest:
It blesseth him that gives and him that takes.
[...] It is enthronèd in the hearts of kings;
It is an attribute to God Himself;
And earthly power doth then show likest God’s
When mercy seasons justice. Therefore, Jew,
Though justice be thy plea, consider this:
That in the course of justice none of us
Should see salvation. We do pray for mercy,
And that same prayer doth teach us all to render
The deeds of mercy.
Portia uses strikingly lyrical language to demonstrate that mercy is not only regal, but holy—it elevates the practitioner to the highest status they could hope to achieve. She envisions an ideal world governed by altruism rather than self-absorption, and she implicates herself, Shylock, and the audience by moving from the third person to first person plural. Portia makes a stronger case for mercy than the Duke does, but Shylock remains unconvinced by the Christian ideals that Portia promotes. While her sentiment may resonate with the rest of the court, it does not affect the one person it's meant to sway, and Shylock demands that the law be executed so that he can get his revenge.
Ironically, despite her exhaustive efforts to commend and advocate for mercy, Portia herself exhibits none when she convicts Shylock later in the scene. Rather than ruling against Shylock from the outset, she manipulates him, making him believe that he can collect his bond, only to reverse course later. Shylock, therefore, is not the only one to disregard Portia's words: Portia herself doesn't seem to heed them, either.