Thank you for your thoughtful response. It’s making me think very hard.

Especially, I wonder how to define mental illness, irrationality, or insanity. Every killer has reasons that seem reasonable to them. They may be bad reasons, but can we define all of them as insane? Your premise seems to be that every rational person knows that killing innocent people is wrong. While I’m no expert in jihad, it seems that what that ideology does is to mark certain people as possible to rightfully kill. To the jihadist, his victims are not innocent; in fact, they’re everything that’s wrong with the world, and he’s performing a service by getting rid of them.

Yes, mental health or illness does play a role. But I think a large part of our motivation involves how we see other people. If we see the potential good in them, and we want that good for them, then we’ll only kill as a last resort and grieve when we have to do it (as in self-defense or war). But if we see people (individuals or groups) as irredeemable threats, or as tools for our own purposes, then we may well co-opt our reason in order to rationalize doing harm to them. If we define that attitude (people are threats or tools) as mental illness, then there are a lot more crazy people than we thought. This mindset doesn’t always lead to mass murder, but it can lead to many other nasty things. Crime. Abuse. Manipulation. Political scheming and unjust laws. Just to name a few. In this piece, I describe it as a “dragonish” attitude, which I have seen in conservatives, liberals, and myself. That’s the real threat, in my opinion. Yes, there is something deeply wrong with anyone who kills innocent people. But I don’t think it’s helpful to slap the label “insane” on all of them while ignoring the problematic attitudes in our own hearts.

Again, thank you. This discussion is really helping me clarify my thoughts and beliefs, even to myself.