"That's from Shakespeare's Macbeth."
"And what is its meaning?"
"The weird sisters are making a charm in the beginning of the play. They have heard the drum that announces Macbeth's coming."
"That is correct."
A new hand shot into the air. "Question, teacher. May I ask a question?"
"You may always ask a question."
"Are witches real? Do you robots know of witches? And do you know of people? Can a roboteacher understand Shakespeare?"
The thin metal voice responded. "Witches are real and unreal. Witches are a part of the reality of the mind, and the human mind is real. We roboteachers are the repository of the human mind. We hold all the wisdom and the knowledge and the aspirations of the human race. We hold these for you, the children, in trust. Your good is our highest law. Do you understand?"
The children nodded. The metallic voice went on. "Let us return to Macbeth for our concluding quotation. The weather, fortune, many things are implied in Macbeth's opening speech. He says, 'So foul and fair a day I have not seen.' The paradox is both human and appropriate. One day you will understand this even more. Repeat the quotation after me, please, and try to understand it."
The childish voices lifted. "So foul and fair a day I have not seen."