Unlike the Prince of Morocco, who preceded him in the play, the Prince of Arragon has no introductory scene in which the audience has an opportunity to learn about his character and personality. Arragon simply appears at Portia's house in Belmont, takes the oath required of every suitor who chooses among the three caskets, and proceeds directly to making his choice among the three caskets of lead, silver, and gold.

One of the functions that the Prince of Arragon serves in the play is to provide the audience with the actual conditions of the oath, which have not been fully stated previously in the play.

ARRAGON. I am enjoin'd by oath to observe three things:
First, never to unfold to any one,
Which casket 'twas I chose; next, if I fail
Of the right casket, never in my life
To woo a maid in way of marriage; Lastly,
If I do fail in fortune of my choice,
Immediately to leave you, and be gone.
(act 2, scene 9, lines 9–15)

Arragon seems to have no reservations about making the oath, and he's ready to make his choice. Through the process of his choice, the choice he makes, and his reaction to his reward, Arragon is shown as a coldly practical, unsentimental, unromantic, and supremely self-confident man.

Arragon immediately rejects the lead casket, which has the inscription "Who chooseth me, must give and hazard all he hath." Arragon has no intention of giving or risking all he has for a lead casket or simply to gain a wife.

As a side note, at no time in the scene does Arragon mention that he has any interest in Portia as a person, that he loves her, or that he's in any way attracted to her. The only time he addresses Portia personally is when he says, "Sweet, adieu" on his way out of the scene. For Arragon, this casket business and the possible acquisition of Portia for his wife seems like nothing more than a business transaction.

Arragon just as readily rejects the gold casket and its inscription, "Who chooseth me, shall gain what many men desire," because he doesn't wish to be thought of as one of "many men" of the "foolish multitude" nor rank himself with common men, the "barbarous multitudes."

The inscription on the silver casket, "Who chooseth me, shall get as much as he deserves," appeals to Arragon's arrogance, which is to say that it appeals to his inflated sense of his own self-importance and self-worth. Arragon convinces himself that he absolutely deserves Portia, and he chooses the silver casket.

Arragon is rewarded with what he deserves, which is a portrait, not of Portia but of a "blinking idiot" and a poem that calls him a fool who came to the choice of caskets with the head of a fool but that goes away with two foolish heads—his own and the portrait of the "blinking idiot."

Arragon makes no mention of losing Portia as his wife, nor does he seem particularly upset about that. Arragon simply can't believe that he chose the wrong casket. "Did I deserve no more than a fool's head?" he says. "Is that my prize? are my deserts no better?"

Arragon promptly leaves the scene with barely a nod to Portia, shaking his head in disbelief as he goes out the door. Portia dismisses him as a moth singed by a candle and has nothing more to say about him as she turns her attention to Bassanio, Portia's own choice for a husband, who has just appeared outside her door, intent on taking his own turn to choose among the caskets.

The reason Portia's father has devised this high-stakes game of caskets as a test of his daughter's suitors is that he was sure the personalities of the suitors would be revealed in the choices they made. This is certainly the case for the Prince of Arragon, who chooses the silver casket.

When he reads the inscription on the silver casket, he decides that it is the one for him because it offers him what he "deserves." The Prince of Arragon has already shown himself to be arrogant in his announcement that he will not choose the golden chest, because its promise of fulfilling his heart's desire would seem to be geared towards the "fool multitude." Arragon thinks he is better than "common" people and that he will be able to make a more reasoned choice than them. He will not throw his choice away on something which he believes would appeal to lesser beings than himself.

On the contrary, he thinks that he deserves everything he has. Because he believes he's such an honorable man, the prince believes that his "offices" and titles are something he is owed. He also believes that he deserves to be Portia's husband, because he is so sure that he is better than everyone else. As such, he opts for the silver casket, believing it will give him what he is owed: Portia's hand in marriage.

It's clear that the Prince of Arragon has a very high opinion of himself. Above all, he thinks he's very clever, certainly too clever not to make the obvious mistake of choosing the golden casket in the little game devised by Portia's father to weed out the gold diggers.

Ironically, however, the arrogance that prevents the prince from choosing the golden casket leads him to make an equally wrong choice in plumping for the silver casket instead. The prince doesn't go for the golden casket, because its inscription reads “Who chooseth me shall gain what many men desire.”

The pompous prince doesn't regard himself on the same level as “many men.” He is a prince, a man with blue blood sloshing around his veins. He's certainly not a member of the common herd. And so he refrains from choosing the gold casket. In doing so, he's making the right decision but for the wrong reasons.

The prince has been taken in by the silver casket's inscription, which reads “Who chooseth me shall get as much as he deserves.” As the entitled prince believes he deserves Portia's hand in marriage, he opts for this casket.

Unfortunately for him, this happens to be the wrong choice. The arrogant Prince of Arragon has ended up with exactly what he deserves.

In Act Two, Scene 9, the Prince of Arragon arrives at Belmont and tries his luck choosing the right casket. After taking an oath to not tell anyone which casket he chooses and agreeing to never propose to anyone for the remainder of his life if he picks the wrong box, the prince reads the inscription on the golden casket. The inscription reads, "Who chooseth me shall gain what many men desire" (Shakespeare, 2.9.24-25). The Prince of Arragon makes the correct choice by not opening the golden casket. He mentions that many people would probably choose the golden casket simply because it is flashy and attractive. The prince says,

"I will not jump with common spirits And rank me with the barbarous multitudes" (Shakespeare, 2.9.32-33).

The Prince of Arragon then reads the inscription on the silver casket, which says, "Who chooseth me shall get as much as he deserves" (Shakespeare, 2.9.36-37). The prince arrogantly believes that he deserves the great privilege of winning Portia's companionship and incorrectly chooses the third casket. However, inside the silver casket is a portrait of a "blinking idiot" holding a letter that ridicules the prince for making the incorrect choice.

In The Merchant of Venice by William Shakespeare, the prince of Aragon chooses the silver casket. It is the one which is labeled 'Choose me and get what you deseerve.' Due to his huge ego and over-inflated opinions of himself, he probably thinks that he will get great things becuase of this - all the ordinary superficial things that most humans want such as money, power, luxury and the attentions that come with that. The phrase is very philosophical and clever when you look at it closely. It does Not say that it will deliver all these things, only that if you deserve good things (which may in any event turn out to be spiritual virtues anyway) you will get them. Think about what a character might get if their weak self-serving character deserves little.

Who chooseth me must give and hazard all he hath.

Who chooseth me shall get as much as he deserves.

I will assume desert.—Give me a key for this,

And instantly unlock my fortunes here.

The trial of the caskets in The Merchant of Venice was intended as a test of character devised by Portia's father to find her a worthy suitor. In selecting the silver casket, the Prince of Arragon fails this test.

While he is determining which of the three caskets he will choose, Arragon's musings reveal a powerful combination of egotism and entitlement. Notably, he rejects the lead casket first, which asks for its chooser to risk all they possess. In response, Arragon states, "you shall look fairer ere I give or hazard" (act 2, scene 9). This dismissal of the lead casket is an insult to Portia herself, viewing her as unworthy of taking such a risk. From here, he moves on to the other two caskets.

His rejection of the gold casket is particularly enlightening, as it reveals the full scale of his arrogance and ego. Consider the following words:

I will not choose what many men desire,

Because I will not jump with common spirits

And rank me with the barbarous multitudes. (act 2, scene 9)

Note here that when reading the message attached to the gold casket, Arragon fixates on two words in particular, the words being "many men." Consider the disdain he holds for commoners and the larger human population. Ultimately, he rejects the gold casket because it would place him in common ground with the masses. This brings him to the silver casket, the selection of which reaffirms that sense of arrogance and entitlement that has been depicted throughout this scene.

After careful deliberation in which he concludes that he is quite deserving of Portia, the Prince of Arragon chooses the silver casket.

Convinced that he deserves Portia, the Prince of Arragon goes through a line of reasoning not unlike that of the previous suitor. He rejects the gold casket because he thinks that only those shallow men who value appearances over other qualities would select the gold. Further, he rejects the lead casket as unfitting for Portia, and it is not beautiful enough for him to risk himself for it.

When he looks at the silver casket, the prince reads on it, “Who chooseth me shall get as much as he deserves” (2.9.51). Believing that he is quite deserving of Portia, the prince then selects the silver casket. However, he is wrong, as inside the silver casket is a fool's head, suggesting that the prince has been foolish to presume that he does deserve Portia. This suggestion greatly angers the prince, but he honors the pledge that he has made, which stipulates that if he loses, he will not reveal which casket he has chosen, he will not marry, and he will immediately depart.

The Prince of Arragon is the second suitor to come try for Portia's hand (the second one we see in the play, anyway), in Act 2, Scene 9. Like the Prince of Morocco, the Prince of Arragon reasons his way through the caskets. The lead is too plain, he suspects, and the gold too ostentatious; the "many" people who value appearances over reality would choose it but would be mistaken to do so.

In considering the silver casket, Arragon considers carefully, reflecting that many who are rich and powerful do not deserve to be so, while many who are poor and weak deserve more wealth and power than they can claim. After much reflection, Arragon decides he does, in fact, deserve Portia, saying:

"'Who chooseth me shall get as much as he deserves.'
I will assume desert. Give me a key for this,
And instantly unlock my fortunes here" (2.9.48-50).

Unfortunately, he unlocks a puppet instead, informing him that he has chosen incorrectly.