The other night on the bus heading back into Seattle a man took a seat up front near the driver. Fiftyish, white hair, casually dressed, and generally unremarkable looking. He gave the seat a once-over with alcohol wipes before he sat down which was odd, but some people have compromised immune systems, or just a thing about germs, so whatever. The bus passed a police car with lights flashing that had pulled someone over. “Looks like the police mafia is out in full force tonight,” the guy said a little too loud to no one in particular. Since bus drivers are the default addressees of comments like this (another reason I’m glad I don’t drive a bus), the driver tried to make conversation about how people often speed along that street–meeting hyperbole with rational small talk, so already: ships passing in the night. They went back and forth for a bit about whether the police department had installed cameras to monitor the traffic. (The bus driver had never noticed any, but the guy was convinced.) He kept working himself up until he made it to the Obama health care plan, which is going to require everyone to have microchips implanted in their heads. The driver tried gamely to say how she didn’t think that was going to happen, which got him even more upset. Louder still: “That’s just one person’s opinion!” followed by a string of angry clichés from someone whose life is a shouting match.
For most of the conversation I thought the guy was merely a lonely loudmouth. It was only when he got to the part about microchips that I decided he was crazy. But why? What exactly is the criteria I’m applying here? At a rough-and-ready level it’s something like Belligerence + Microchips, Radio Waves, the CIA, or Religious Grandiosity = Schizophrenia. Though that’s good enough for avoiding unpleasant confrontations on the street, I don’t want to be consigning people to madness simply because their false beliefs are clichés. That goes too far down the path of defining madness as a purely social construct, which I don’t believe to be the case, so I feel the need to come up with a more principled definition. Crucially I want a something that still counts the guy on the bus as crazy even if it turns out that Obama actually was mandating universal microchip implants all along.
The trick is this–you imagine a number of alternate worlds, and you imagine the beliefs this guy would hold in those worlds. Then you imagine the degree of variation in those beliefs. For most people, beliefs vary with worlds. One set for this world, another for a world in which the CIA’s use of mind-controlling radio waves transmitted through radiators is a widely reported fact. If you’re crazy, the worlds change but the beliefs stay the same. Sanity is the difference in the spread.