> I think it was Hermann Hesse who wrote that "If you hate a person, you hate something in him that is part of yourself. What isn't part of ourselves doesn't disturb us."

This sounds nice and pithy, but it's trivial to debunk. Beheading someone is not part of myself, but it most certainly disturbs me. And I certainly wouldn't be hating something in myself by hating someone who perpetrated such a grisly crime.