Final answer:
Graff tells Ender that all human beings are capable of great cruelty.
Step-by-step explanation:
Graff tells Ender that all human beings are capable of great cruelty.
In the book, Ender's Game, Graff explains to Ender that humans have the capacity for both good and evil. He argues that the potential for cruelty exists within every person, and this is demonstrated through the actions of certain characters in the story.
An example of this is Ender himself, who is pushed to his limits and displays a level of brutality in his actions during the Battle School. This theme of the potential for violence in all individuals is a recurring theme in the novel.