That's the same thing - you still gotta know how to fight 'em. The generals know how to fight, so why the hell don't you? Don't you think it's foolish to send men out to die without understandin' what you're puttin' 'em through?

[All of his masters have been warriors, even the generals who later rested on their laurels. They started on the battlefield, wading across the Japan Sea, taking heads and bringing back trophies. To think that anyone involved with a war wasn't a warrior themselves was against everything he stands for.]

Humans are going to kill the hell out of each other, whether they're related or not. It's all the more reason you need to learn.