The word ‘pedant’ is used in a generally negative sense, to describe someone who makes a great display of learning, just to show off his or her knowledge, and often insists too much on rules and regulations. Dr Jekyll describes his old acquaintance Dr Lanyon in this way, in chapter 3 of the novel. This illustrates the difference between these two characters. Lanyon is quite formal and conservative whereas Jekyll wants to push back boundaries, attempt new things in the course of his research, which leads him to making the potion that transforms him into his dark alter ego, Hyde. Lanyon would never dream of using knowledge for such unsavoury purposes, as Jekyll does, and later, when he actually sees Hyde transforming back into Jekyll, he is so appalled that he soon dies.