I first learned to be a skeptic in high school. Pause. Modify. I think I was always naturally a skeptic – or, as my mother frequently put it, “Everything I say, you always give me an argument.” But in high school there were two occasions where basic principles about how to be one presented themselves. By the time of these two incidents, we had already read (in eighth grade, when I was 12-13) Isaac Asimov’s The Human Body: Its Structure and Operation.