Why Do People Kill?

My latest conversation with Austin in the car:

NPR is on.

Austin: Daddy, a lot of people get killed in wars.

Me: Yes. (Turns off radio.)

Silence.

Austin: Why do people kill?

Me (after some thought): Well, if someone is going to hurt them, and they kill that person, that's called self-defense.

Also sometimes people kill to steal something.

Austin: Like pirates.

Me: Yes, pirates kill and steal people's boats.

Austin: Or gold.

Me: And also there are people who are just crazy. None of these are really good reasons for killing, are they?

Austin: No.

Silence.

Austin: Or they're hungry.

Me: What?

Austin: Like, if someone wants to eat a chicken, they kill the chicken. Or if they want turkey, they kill a turkey. Or if they want to make a fire, they chop down a tree.

Me: Yes.