Blindness is a very important theme running right through Shakespeare's The Merchant of Venice. It goes from the actual physical blindness of Old Gobbo to the metaphorical blindness of Antonio through to the emotional blindness of Shylock.

Old Gobbo is blind, or functionally blind at the very least. Because of his blindness, he's unable to recognize his own son Lancelot in a scene that's played for laughs. As well as being literally blind, Old Gobbo is figuratively blind in that he's not a particularly wise man. As Lancelot ruefully reflects, even if his old man had perfect eyesight, there's still every reason to believe that he wouldn't really know him.

Metaphorical blindness comes to the fore in the character of Antonio. He displays blind loyalty to Bassanio, even at the cost of his business and, potentially, his life. Successive generations of playgoers have scratched their heads at what they see as the strange behavior Antonio exhibits towards this improvident youth. They have wondered how anyone who makes his living as a businessman could be quite such a soft touch in bailing someone out, even if they're a friend.

On this particular occasion, it's Antonio who borrows money from Shylock in order to give it to Bassanio. In doing so, he's showing blind loyalty to someone who perhaps doesn't deserve it. The consequences of this action come close to being very deadly indeed.

Now that Portia's father is dead, the choice of a future husband has been left to blind fortune by way of the casket game. The game was devised by Portia's father as a way of keeping gold-diggers from her door.

Whoever chooses the casket will win Portia's hand in marriage. This will be decided largely by the forces of fortune, which are, of course, blind. That being the case, Portia tries to make things a little more predictable by dropping massive hints during the casket test to ensure that the man she wants, Bassanio, chooses the right casket and takes her hand in marriage.

Finally, we have Shylock. His blindness is primarily emotional. His whole life revolves around business, and so he's unable to develop close relationships with anyone, not even his own daughter Jessica, who runs away from home in order to escape her father's domestic tyranny.

A certain moral blindness can also be seen in Shylock's attitude towards Christians. Understandably, given the anti-Semitic abuse he has to put up with on a daily basis, Shylock loathes Christians for the way they treat him. At the same time, Shylock's hatred of Christians eats him up to such an extent that he becomes vindictive in his legal case against Antonio. Shylock over-reaches himself, and in the process is forced to converse to Christianity.

How is the theme of blindness demonstrated by Shakespeare in The Merchant of Venice? Explain with these characters: Old Gobbo, Portia, Antonio, and Shylock.

Blindness and insight are central themes in The Merchant of Venice, and Shakespeare explores these in various ways during the course of the play. The blindness that is most problematic—and most critiqued—is metaphoric blindness or an inability to perceive the reality of a situation.

This is highlighted through Old Gobbo, a minor character in the play who provides comic relief but also does double duty in drawing attention to the blindness theme. He is physically blind, but, more importantly, he is "blind" to recognizing his son's voice, even though his hearing is intact. In act II, scene ii, he says to his son Launcelot:

Alack, sir, I am sand-blind; I know you not.

Launcelot rightly intuits that it is not a physical but a relational handicap, a lack of love, that causes Old Gobbo to have trouble recognizing his voice. As Launcelot says:

Nay, indeed, if you had your eyes, you might fail of
the knowing me: it is a wise father that knows his
own child.

In other words, physical blindness is an excuse: Gobbo should be able to recognize his son in other ways. This contrast is highlighted when Lorenzo, in act 2, scene 6 can discern his beloved Jessica in the dark by her voice.

Portia is metaphorically blinded by her father's will and by her gender. In these cases, blindness is a form of constraint—like a blind or blindfolded person, Portia cannot move as freely as she would like. Her gender becomes a restraint because she is not allowed to choose her own husband and cannot, as a woman, defend Antonio in law court. However, Portia demonstrates her ingenuity and superior ability (suggesting that it is the men who are actually blind in strait-jacketing women into subordinate roles) by having music played that helps guide Bassanio towards picking the right casket and disguising herself as a male lawyer to be able to save Antonio.

Jessica says "love is blind," and this theme plays out in Antonio, who is so blinded by love or affection for Bassanio that he dismisses the risk he is taking in agreeing to Shylock's terms for the loan. This costs him dearly, as he almost loses his life. Antonio also represents generalized male blindness to female ability: he does not recognize that it is Portia dressed as a male lawyer. He is also blind to the implications of how he has treated Shylock and, by extension, Jews in particular, blithely sure of his power and privilege to the point of not seeing the seething anger and resentment he has raised in Shylock through his arrogant and abusive treatment of him.

Finally, Shylock is metaphorically blinded by his desire for revenge. He so badly wants to get back at Antonio, the epitome of abusive privilege, that he loses sight of the fact that his revenge scheme is too gruesome to be reasonable, and that, as a Jew, he is unlikely to encounter a level playing field in a Venetian law court. He is also blind to his daughter's resentment of him and desire to marry Lorenzo.

Lack of perception and empathy is a chief cause of blindness in this play, as is love.