That is the earth, he thought. Not a globe thousands of kilometers around, but a forest with a shining lake, a house hidden at the crest of a hill, high in the trees, a grassy slope leading upwards from the water, fish leaping and birds strafing to take the bugs that lived at the border between water and sky. Earth was the constant noise of crickets, and winds, and birds

An enemy, Ender Wiggin," whispered the old man. "I am your enemy, the first one you've ever had who was smarter than you. There is no teacher but the enemy. No one but the enemy will tell you what the enemy is going to do. No one but the enemy will ever teach you how to destroy and conquer. Only the enemy shows you where you are weak. Only the enemy tells you where he is strong. And the rules of the game are what you can do to him and what you can stop him from doing to you. I am your enemy from now on. From now on I am your teacher.

I'll have that someday, thought Peter. Someone who'll kiss me good-bye at the door. Or maybe just someone to put a blindfold over my head before they shoot me. Depending on how things turn out.

That's the problem with winning right from the start, thought Ender. you lose friends.

Personal affection is a luxury you can have only after all your enemies are eliminated. Until then, everyone you love is a hostage, sapping your courage and corrupting your judgment.

The criminal misuse of time was pointing out the mistakes. Catching them―noticing them―that was essential. If you did not in your own mind distinguish between useful and erroneous information, then you were not learning at all, you were merely replacing ignorance with false belief, which was no improvement. The part of the man's statement that was true, however, was about the uselessness of speaking up. If I know that the teacher is wrong, and say nothing, then I remain the only one who knows, and that gives me an advantage over those who believe the teacher.

Reasonable argument is impossible when authority becomes the arbiter.