We’re starting a unit on logic in my seventh grade classes. This was today’s warm-up. I had a blast sharing knight and knave (and normal and vampire and insane vampires and…) problems with my seventh graders two years ago, and so I’m totally pumped to dig in with these new kids.
I first encountered the books of Raymond Smullyan when I was maybe a little older than seventh grade, and I totally loved them. I remember being really struck by the notions of vacuous definitions and falsifiability (“All unicorns are purple” is true), and of course I was super into pondering puzzles about rooms with tigers and coffins and so on.
Sharing the delights of these puzzles with kids feels special to me because of what they meant to me from an early age. This feels to me, more than other things, like passing on treasures from one generation to another. Maybe that’s because I’ve come to appreciate or love other parts of mathematics in new ways since I’ve become an adult—how I feel about algebra, for instance, has definitely grown with time.
“Raymond Smullyan and I are both knaves.”