 The appeal to implicitly followed linguistic rules casts a revealing light on Grice as a champion of the view that communication is an exercise in rational coordination through acts of speaker meaning. Since Grice, a central question has been “[h]ow much of this coordination derives from interlocutors’ specific knowledge of one another as people? How much exploits their knowledge of language itself?” (Lepore and Stone 2015, 1). With the appeal to implicitly followed rules, Grice has one foot squarely on “knowledge of language itself” side of that divide.