The purpose of the play within the play is to further illustrate Shakespeare's theme of reality vs. illusion. In fact, the mechanicals' performance of the play shows us just how much reality is actually governed by illusion, or fantasy.
The mechanicals' have made a very ambitious choice to write their own play and perform it before Duke Theseus and Hippolyta in honor of their wedding day. Their choice is particularly ambitious because they are common laborers who are uneducated. Flute is a bellows maker; Quince is a carpenter; Snout is a tinker who mends pots and kettles and such; and Snug is a joiner, which is a particular type of carpenter who specializes in doors, windows, and paneling. As Philostrate points out, they are "[h]ard-handed men that work in Athens here, / Which never labour'd in their minds till now" (V.i.76-77). Since the mechanicals have been so ambitious, we see that the reality is that they are incapable of producing the quality of play that they had actually envisioned producing, showing us that they have actually let their fantasies govern reality.
We especially see the ridiculousness of their ambitions when we see them begin to practice and work out their play. In particular, Bottom is ridiculously ambitious when he sees himself performing every major role of the play, even asking to play both Pyramus and Thisbe as well as the lion. His ridiculousness makes him act like the proverbial ass, as Puck feels obliged to point out. We also see the absurdity of their ambition when we witness the mechanicals coming up with comical solutions to their problems, such as a prologue telling the audience that everything that happens in the play is fictitious so that the ladies are not upset by Pyramus's suicide or frightened by the lion. They also come up with the absurd solution to have an actor play the part of the wall and "hold his fingers thus" to represent the chink in the wall so that Pyramus and Thisbe can whisper through the chink (III.i.63-64). They also have an actor dress up as the man in the moon, but he also, for no known reason, brings on stage with him a bush and his dog. Thus, since the mechanicals do such a poor job of presenting the play, we see that they have let their fantasies, or their illusions, govern their reality.
Hence, we see that the purpose of the play within the play is to further portray the theme of reality vs. fantasy and to show that fantasy governs reality.
One of the notable characteristics of the dramatic construction and presentation of William Shakespeare’s play A Midsummer Night’s Dream is the fact that it contains two distinctly different plays within the larger framework of the main play. The author’s skillful development and juxtaposition of these simultaneously unfolding plays serves the function of reiterating some of A Midsummer Night’s Dream’s principal themes. Similarly, the utilization of this multiple play structure also situates Shakespeare in relationship to the creative process and his own work. Furthermore, the three-play structure allows the reader to question the very nature of creativity and of love. The play staged by the mechanicals is particularly effective in this regard. The comic, lighthearted tone of the players as they prepare for and fulfill their roles in Pyramus and Thisbe serves as a welcome contrast to the more dramatic circumstances between the women characters in “A Midsummer Night’s Dream” and Hermia, Lysander, Helen, and Demetrius, as well as the more fanciful plot involving the faeries. Even more than these other plays, the play of the mechanicals raises a number of important questions about life, love, and creative production and performance.
The lower class laborers who comprise the unlikely dramatic troupe which will perform Pyramus and Thisbe are introduced to the reader in Act I, Scene II of A Midsummer Night’s Dream. Everything about these players is comical, from their most superficial characteristics to their deeply embedded personality traits which include a habit of bumbling, mispronouncing words so that the meanings of their sentences are completely and comically misconstrued, and generally playing the part of fools. As soon as the reader learns of the rag-tag actors’ names—Bottom, Flute, Snug, Snout, Starveling, and Quince– he or she becomes immediately oriented to the fact that the introduction of these characters is intended to disrupt the larger narrative of the play and if anything, provide further comic relief to the slightly more serious (although still lighthearted) main narrative. Additionally, these goofy characters also exist to raise questions about the subjects and themes in “A Midsummer Night’s Dream” that are most present throughout the work. This observation is confirmed with each new detail that the reader learns about each of the tradesmen/actor characters. Nick Bottom is a weaver who, like his fellow tradesmen, has no previous acting credentials. In fact, it is not entirely clear how these men have come together or who decided that they were “worthy" of putting on a play. This issue of worthiness, or fitness, for playing certain roles, whether on the stage or on life, is a central theme and preoccupation in A Midsummer Night’s Dream.
Upon learning that he will be assigned to play the lead role of Pyramus, “a lover that kills himself most gallant for love" (Shakespeare 17), Bottom asserts that he will be so effective in his role that he will elicit the audience members’ tears: “I will move storms," he proclaims to his fellow actors (Shakespeare 17). Flute is also comical and in many ways, he acts as a comic foil for Bottom, especially as Bottom ends up taking himself seriously, despite the fact that the audience is well aware of the situation. For Flute’s part, he begs not to be cast as a female character because he has “a beard coming" (Shakespeare 18). Bottom will also evidence a preoccupation with his beard later in the play, as he questions the other cast members how he should wear his beard so that it will be most appropriate and most convincing for his role. While these details may seem to be little more than humorous distractions, they actually serve much more profound purposes in the overall scheme of the play. In a certain sense, Shakespeare seems to be using these amateur actors as a way of opening a conversation both with himself and with the reader about the nature of the creative process. The actors are so preoccupied with the minutiae of their newfound dramatic craft, yet they fail to engage more important creative concerns, such as correct pronunciation and the mastery of crucial dramatic resources and techniques, including memorization, line cues, timing, and the congruence of affect with speech. Quince spends much of the troupe’s rehearsal time trying to harmonize the untutored actors so that their performance will eventually, hopefully, play out seamlessly. While it can be suggested that Shakespeare is merely offering a comical interlude to discuss the creative process, there is also the dual purpose of how these issues make the reader even more keenly aware of some of the major themes in “A Midsummer Night’s Dream” by William Shakespeare