The very title of A Midsummer Night's Dream suggests the whole play is a flight of imagination and fancy. Only in a dream could the Greek-myth figures of Hippolyta and Theseus, fairy royalty such as Titania and Oberon, Bottom and the other rude mechanicals, and the two sets of beleaguered lovers (plus parents) wind up in the same play. Yet that is precisely what happens. Moreover, each of these groups interacts with at least one of the others over the course of the action, and all of the groups come together in the onstage action of Act V--having such a wonderful time that Puck has to step in at the end and remind everybody in sight to wake up: "Think but this, and all is mended, / That you have but slumber'd here / While these visions did appear" (V.i.431-33). Webster cites the multiple references to the moon and magic throughout the play, calling it "delicately ethereal" (155).
The overall action is not the only dream-relevant aspect of the play. Dreaming also figures in action content. Theseus anxiously anticipates the four days before his wedding, but Hippolyta suggests he relax: "Four nights will quickly dream away the time" (I.i.8). Thus although they may be impatient while awake, their dream time at night will give them rest and move them toward the event.
Eager anticipation of marriage thus established as the opening theme of the play, the action takes a more serious turn with Egeus and Hermia, who is defying her father over a choice of husband.
Right at the beginning, it's an ugly situation. Hermia's father, Egeus, . . . didn't give her any [choice] . . . I could imagine this story, the bare plot, being made into a pretty unpleasant story (Brown, et al. 211-12).
In Hermia's dilemma over marriage surface several different dreams, or visions, of the future. Hermia and Egeus share a dream of her future as being happy in loving husband and family, but the contents of their dreams differ dramatically. Egeus sees Demetri...