I can’t recall who said it, a writer who had been an investigator with the FBI or police, “People have an internal logical consistency. Whatever they do conforms to that logical consistency. If you can figure out what it is, you can understand what they do and why they do it, whether you agree with it or not.” I have people in my life whose “internal logical consistency” is completely unfathomable to me. I can guarantee they will say or do something horrible, but I often can’t anticipate what it will be and am repeatedly surprised by how incredibly awful they can be. They seem to plumb new depths of awful, of inconsideration, of the incomprehensible.
I am fond of saying that you can’t reason with crazy. That doesn’t stop me from trying to figure it out, to figure out the internal logical consistency by which these people operate.