One thematic idea in Ray Bradbury's "All Summer in a Day" is that of the darkness of the unenlightened mind.
In his short stories, Bradbury frequently uses imagery, such as that of the sun. Sun imagery is often representative of God and enlightenment. Because the children who have lived on Venus most of their lives have not seen the sun, they are limited in their perspectives. For this reason, they resent Margot's little verse that is superior to theirs, even accusing her of not having written these lines:
I think the sun is a flower,
That blooms for just one hour.
Further, in the darkness of their minds, they hate Margot for her memory of the experience of the heat and color of the sun, an experience that they were too young to remember because they came to Venus sooner than she. When the day arrives for the sun's appearance after seven years, one cruel boy pretends that it is not the day that the sun comes out. He declares that nothing is going to happen. In the absence of the teacher who would correct the boy, the others go along with him. The cruel boy seizes her, and the others assist him in putting Margot into a dark closet. They lock the door. When the sun comes out for an hour, the children run excitedly, pressing their fingers to their faces where the warm, golden rays touch them.
Then, wildly, like animals escaped from their caves, they ran and ran in shouting circles.
After the hour of sun ends,
They looked at each other and then looked away. They glanced out at the world that was raining now. . . . They could not meet each other’s glances. Their faces were solemn and pale. They looked at their hands and feet, their faces down.
The light of the sun has given them self-knowledge and shown them the shamefulness of their actions in depriving Margot of the incredible experience that has just occurred. For they know now the truth of what Margot has said about the sun. In their enlightenment, the children realize the terrible wrong that they have committed against this girl because of the darkness of their own minds.