 We follow shared rules, they say, in using any word: these rules set out criteria that supply the word’s meaning. Our rules for using ‘law’ tie law to plain historical fact.… Philosophers of law must elucidate them for us by a sensitive study of how we speak. They may disagree among themselves, but that alone casts no doubt on their common assumption, which is that we do share some set of standards about how ‘law’ is to be used. (Dworkin, 1986b, 31)