The scene is the public square outside Corvino's home, slightly later in the day. Sir Politic Would-be, the English knight residing in Venice, and Peregrine, an English traveler who has just arrived in Venice, are strolling together. Sir Politic explains that is was his wife's wish that the two should go to Venice, for she desired to pick up some of the local culture. He asks Peregrine (whose name derives from the word peregrination, or wandering travel) for news from the home country, and says that he has heard many strange things from England; for example, a raven has been building a nest in one of the king' ships. Having decided that Sir Politic will believe anything anyone tells him, as his name indicates, Peregrine proceeds to let him tell some more improbable stories for his and the audience's amusement, including the one about Mas' Stone, the supposed drunken illiterate who Politic is convinced was a dangerous spy. According to Politic, Stone had secret messages smuggled out of the Netherlands in cabbages. To see just how much Politic will pretend to know, Peregrine mentions a race of spy baboons living near to China. Politic, of course, says he has heard of them, and calls them "the Mameluchi", another name for the Mamelukes (who were actually an Egyptian dynasty that had nothing to do with either China or baboons). Peregrine says, sarcastically, that he is fortunate to have run into Sir Politic, because he has only read books about Italy, and needs some advice on how to negotiate his way through Venetian life. Sir Politic seems to be agreeing when Peregrine interrupts him, asking him to identify the people entering the square.
This scene introduces us to the Sir Politic Would-be subplot of Volpone. The subplot is a key component of Elizabethan drama; it is a secondary storyline which, like a variation on a theme, should take up the themes of the main story, or related themes, and treats them in a slightly different way, either with a different tone or with a different emphasis. The subplot usually often revolves around a central character that plays a less central role in the main plot. Volpone has been criticized for the fact that the central characters in its subplot-Sir Politic, Lady Politic and Peregrine-play almost no role in the central plot. But the satirical intent of the two plots and their light-hearted tone are similar, as are their focus on gullibility. In the main plot, the gullibility of the main characters is inspired by their greed. In the subplot instead of satirizing greed, Jonson attacks another selfish virtue, that of vanity. Sir Politic considers himself wise and learned, and wants everyone to see him that way; he speaks confidently of knowing the ways of Venetians, even though he has only lived in Venice a short while. His name gives us the central indication of his vice, that he "would be politic," or knowledgeable, if he could; his desire to appear so at all costs makes him agree to anything anyone says as if he knew it already, before trying to add his own bit of (usually incorrect) insight to the statement. His situation is ironic (situationally) because in trying so hard to appear knowledgeable, he in fact appears gullible and stupid to anyone who meets him for even the briefest period of time—such as Peregrine.
The Sir Politic subplot is also directed to a specific segment of Jonson's audience, namely Italo-phile Englishmen like himself, for whom a very serious issue at the time was whether or not Englishmen in love with the grandeur of Italian civilization should take the risk of traveling to Italy. The "risk" involved was not that of disease or death, but of "moral degeneration"; Italy was seen as a corrupt and decadent place, full of liars, swindlers, and immoral hedonists, and Englishmen who traveled there risked bringing the moral contagion of vanity and deceit back to the mother country, as if introducing a previously unknown disease to their homeland. Indeed, Venice was the corrupt, decadent city; as we can see from the main plot, where every single character is engaged in some form of deceit, Jonson's portrayal of Venetian life fully buys into the stereotype, and the play's setting probably lent it a great deal of believability in the eyes of its English audiences. Sir Politic functions serves, then, as an example of all Englishmen who go to Italy and are corrupted by its decadent ways. The satire leveled against his vanity is also leveled against his desire to talk and act like Italians (in the eyes of Jonson's compatriots, they were just about the same thing). Peregrine, on the other hand, is a model of how one should behave in Italy; his named, which comes from the Latin for "wanderer", indicates that he is just passing through this foreign land. Furthermore, he has been instructed well by "he that cried Italian" to him, in other words his tutor, who instructed him using a "common grammar." This was probably one of the travel books then widely available, published by educated Italo-philes, giving instructions on how to go to Italy without being corrupt; they were full of various bits of helpful advice such as "never let a Venetian know where you live, or any other important facts about you"; and they were seen as a kind of inoculation, if you will, against whatever "virus" the Italians had that made them so mean.