I've been thinking about what makes a villain work in fiction. The villains I find most compelling are the ones who believe they're right — not the ones who know they're doing wrong and do it anyway, but the ones who have constructed a coherent justification for everything they do.

The Judge in Blood Meridian is the most terrifying character in American fiction because his philosophy is coherent. He believes in war as the highest human activity, in violence as the expression of will, in the world as a place where those who hesitate deserve to lose. The horror is that this is a position, not a madness. You can see the internal logic.

Lord Tywin Lannister works in a similar way in the Song of Ice and Fire novels. He's not evil in the way his son Cersei is evil — reactive, personal, emotional. He's strategic in a way that is almost admirable until you see what the strategy costs.

The villain who is a person rather than a force is always more disturbing than the villain who is simply dangerous.