Proteus' servant Launce, dragging his dog, Crab, and dilly-dallying en route to his master's departing ship, complains that Crab is the surliest dog that ever lived. He laments that his family cried bitterly when he bade them farewell upon his departure for the emperor's court, while the dog has continued neither to speak a word of sorrow nor to shed a tear of sympathy. Launce enacts the entire farewell scene with his shoes and apparel: the shoe with the hole in the toe stands in for his mother, and the shoe without the hole for his father; his staff stands in for his sister, and his hat for the family's maid. Confusion ensues as Launce debates whether he or Crab should play Launce. Panthino arrives to fetch Launce, interrupting his production.
Valentine and Thurio, a boorish admirer of Silvia's, show off in front of Silvia. Speed stands by, trying to start a fight between the rivals by encouraging Valentine to punch Thurio. Silvia commends the men for their witty dialogue as the Duke enters.
The Duke marvels at the number of admirers clustering around Silvia, and asks Valentine about his friend Proteus. Valentine praises Proteus, calling him a perfect gentleman. The Duke announces that Proteus will arrive momentarily. When Proteus arrives, Valentine introduces him to Silvia. Silvia and Thurio exit promptly. Valentine admits to Proteus that he has fallen in love, despite his past criticism of Proteus for succumbing to a woman's sweet ways. Valentine presses his friend to admit that Silvia's beauty is divine and exceeds that of any living woman, but Proteus refuses to concede. Valentine confesses that he and Silvia are betrothed and that they plan to elope that night; he has a ladder made of cords and plans to climb to Silvia's window and ferry her away. Valentine asks Proteus to advise him about the plan, but Proteus weakly invents some pressing business. After Valentine exits, Proteus admits that he, too, has fallen in love with Silvia, having all but forgotten Julia in the face of this more beautiful competitor. Proteus ominously says that because he loves Silvia so much, he cannot love Valentine at all.
The difference in style of speech between Launce and Proteus reflects the opposite social statuses of the two. Launce, a rudimentary precursor to the witty, amoral Falstaff (see Henry IV Part I , Henry IV Part II , and The Merry Wives of Windsor ), speaks entirely in prose. The inferiority of Launce's diction, in addition to the rather unpoetic quality of his speeches, illustrates the "low" nature of his character: he is a member of the serving class rather than the nobility. Proteus, on the other hand, ends his soliloquy with the flourish of a rhyming couplet, exemplifying his refined, gentlemanly nature (compare II.iv.206-207 to II.iii.26-28).
Launce's departure from home parallels Proteus' arrival at the Duke's court. The juxtaposition of Launce's melodramatic laments concerning his farewell, despite their seeming irrelevance, and Proteus' hungry musings on love establishes Launce as a foil for Proteus. Launce provides an honest emotional commentary, his departure being a source of great sadness; Proteus, however, whose namesake is a sea god in Greek mythology capable of appearing in various forms, supplants his love for Julia with a love for Silvia, putting the sincerity and depth of his emotions in question. The contrast between these two scenes demonstrates that nobleness of birth does not necessarily equate with nobleness of character. Further, it suggests that the stylized and romanticized loves for which both Valentine and Proteus suffer contain neither the depth nor the endurance of Launce's relations: though his reenactment with ratty shoes is foolish, Launce proves himself more warm and caring than Proteus.
One can pair this soliloquy of Launce's with his later one, both of which are seemingly silly commentaries about his relationship to his dog, and read them as Shakespeare's own comments on life as a playwright, with the dog representing a fickle public or an elusive muse (II.iii.1-28, IV.iv.1-33). In the humorous naming of a dog "Crab," Shakespeare comments on the ephemeral nature of language, and, since language is the chief means by which humans communicate, the difficulty in connecting to others (the failure of Proteus' letter to reach Julia directly can be seen as a literalization of this difficulty). One can interpret Shakespeare's exploration of the flexibility of language as a frustration at language's inability to fully explain true friendship and affection, or as the manifestation of a pessimistic belief that the possibility of true friendship and affection (Proteus claims to be a trustworthy friend and lover) is as ridiculous as someone naming a dog Crab.