[She takes a moment to think on the best way to explain it.]It's the first principle taught to meisters and weapons. It's the basis for learning to distinguish between human souls and kishin eggs when we perceive souls.

[She can only watch him, closing her eyes as she speaks. Tsubaki knows she probably can't convince him, but feels the need to voice her thoughts.] You seem terribly certain. It might just be my perspective, but no one can be accurate in such predictions. Then again, my home understandings probably do not apply to other worlds.

[Bows her head slightly, sincere, but somehow still honest and firm.] I hope I'm not speaking out of turn, but that is my opinion.