What does this quotation mean? "I'm a murderer, even when I play. Peter would be proud of me."
Ender, who was the second boy to be chosen from his family, is aware that his big brother Peter was kicked out of the program because he was too violent. Even at the beginning of the book, when Ender injures a schoolmate, then kicks him, to make sure the other boys watching will never gang up on him, he worries that he is too much like Peter. Later, when he injures a fellow-trainee (Bonzo?) he again chastises himself for being too much like Peter. The actual parable in the book is about how war violence, which we learn from history, makes us as evil as the so-called villains of history—Attila, Hitler, etc. Only after the Buggers are destroyed does the parable give its lesson (one echoed in Ender’s learning from his opponents in the simulations): we should look at the culture we call our enemies—perhaps they are not evil after all, just different. The neonatal colony Ender finds and preserves at the end is symbolic of Card’s message. The quote, then, is saying “Am I (the reader) as violent and evil as those I consider my enemies—the bullies at school, for example?”