I first saw reference to this clip in the book They Say/I Say by Gerald Graff and Kathy Birkenstein. The book–which is now well on its way to classic status–shares the authors’ method for teaching academic writing at the University of Illinois-Chicago. It’s well worth checking out for both secondary and postsecondary writing instruction. In their book, they reference this scene from Monty Python where two characters end up arguing about what an argument is. It’s a fantastic clip to use with students, one that I’ve used many times.