When you really know someone, you can't hate him.

Human beings are free except when humanity needs them. Maybe humanity needs you. To do something. Maybe humanity needs me—to find out what you're good for. We might both do despicable things, Ender, but if humankind survives, then we were good tools.

The only process you've mastered is the process of elimination, and the only reason you've mastered that is because you can do it in the toilet.

Humanity does not ask us to be happy. It merely asks us to be brilliant on its behalf.

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.

Life is full of grief, to exactly the degree we allow ourselves to love other people.

There's a reason why every human society has fiction. It teaches us how to be 'good,' to behave in a way that is for the benefit of the whole community.