In my opinion, the author tackles a number of ethical issues. Murder without punishment, the manipulation of children, the disengagement of people from society...... the inability to show empathy. Adults use children for their own ends because their own minds are so lacking in compassion and innocence that they cannot comprehend them. Card is emphatically against this manipulation and the way it effects children's minds, in essence, creating yet another unfeeling, emotionally detached generation.
For additional information, check out GradeSaver's theme page in the study guide for this unit.