Discuss the relationship between Antonio and Bassanio in William Shakespeare's The Merchant of Venice. What does their friendship reveal about...

The relationship between Antonio and Bassanio in William Shakespeare's The Merchant of Venice is one of deep love and respect. These two characters have a bond that is unshakeable. As Act I of The Merchant of Venice begins, Antonio, the titular merchant, is engaged in conversation with Salarino and Solanio, two friends with whom both he and Bassanio are close. An early indication of the closeness of the relationship between Antonio and Bassanio is provided at the outset. As Antonio, Salarino, and Solanio speak, the latter two prepare to depart—but not without noticing that Bassanio approaches, prompting Solanio to remark, "Here comes Bassanio, your most noble kinsman...." 

That something is troubling Antonio is apparent to all of his friends. Solanio and Salarino remark upon their friend's demeanor, and, now, Gratiano and Lorenzo, who accompany Bassanio, similarly notice Antonio's depression:

GRATIANO

You look not well, Signior Antonio;
You have too much respect upon the world:
They lose it that do buy it with much care:
Believe me, you are marvellously changed.

ANTONIO

I hold the world but as the world, Gratiano;
A stage where every man must play a part,
And mine a sad one.

So we know that Antonio is much loved by his friends, but these well-meaning gentlemen are mistaken in assuming that Antonio's worries center around the burden of his business ventures. As the audience soon learns, it is not business that is currently on Antonio's mind so much as it is his dearest friend Bassanio's situation. Bassanio is in love with Portia but needs money, which he usually borrows from Antonio, in order to properly woo her in this exceedingly class-conscious environment. It is his friend's romantic yearnings that propel Antonio into the fateful arrangement with the Jewish moneylender Shylock. Unable to raise the requisite funds Bassanio needs from his heavily leveraged business arrangements, Antonio borrows money from Shylock, despite the latter's unconventional condition:

In such a place, such sum or sums as are
Express'd in the condition, let the forfeit
Be nominated for an equal pound
Of your fair flesh, to be cut off and taken
In what part of your body pleaseth me.

What do we learn about the natures of Antonio and Bassanio from their friendship? We learn that these two individuals are passionate about their lives and that they are more than a little loyal to each other.  So loyal to Bassanio is Antonio that he agrees to a business transaction with Shylock that involves the mutilation of his body in the event he is unable to repay the loan--a serious gesture even with his confidence that such drastic measures will not prove necessary. We learn that Bassanio is a true friend to Antonio but one who is financially irresponsible and, as a consequence, abusive, perhaps, of his friend's munificent nature. It is, after all, Bassanio's irresponsible conduct that results in Antonio's dangerous business arrangement with Shylock. We also learn that these gentlemen are anti-Semitic, and that the anti-Semitism that permeates the culture in which they exist will, ultimately, save Antonio from having to make good on his debt.