Until only a few hundred years ago doctors didn’t operate on people — it was barbers. No-one had taught them and they’d never got any qualifications. They just did what they’d learned when they were learning to be barbers. Doctors had promised not to hurt anyone so they wouldn’t cut people and were not even supposed to watch. But the doctors did watch if they were following the rules properly and he sat on a big chair, high up, and read out what the barber was supposed to do. He read this in Latin, which, of course, the barber didn’t understand. Of course, if you died, it was always the barber’s fault and if you got better, the doctor got the praise. In any case, the doctor got the most money.