 Philosophy of law can gain from a good philosophical account of the meaning and use of language, and from a good philosophical account of the institutionalized resolution of disputes over language. Philosophy of language can gain from studying the stress-testing of language in legal regulation and dispute resolution. And philosophers of language can gain from the reminder that their task is not only to account for what people share in virtue of the mastery of a language; they also need to account for the possibility of disagreements over the meaning and use of language, and for the possibility that there might be good reason for resolving those disagreements in one way rather than another.