What did the Roman lawyers mean when they spoke of ius? The question is an important one not only for an understanding of Roman legal concepts but also for the history of Western law generally. Beginning in the twelfth century and extending to today, the texts of Roman law have been studied with an assiduity second only to that devoted to the Bible. A concept as fundamental as ius could not fail to have influenced Western legal thought, particularly because, in many periods, those who studied the Roman texts also sought to apply what they learned in those texts to the law of their own time. The question is not only important, it is also difficult. The word “ius” in Latin (like droit in French, Recht in German, etc.) is ambiguous. It can mean a whole body of normative rules, a legal order, as well as “right,” in any of the many senses of the English word. (The absence of this ambiguity in English is more than compensated for by the notorious ambiguity of the word “law,” which can mean either lex, in the sense of statute or rule, or ius, in the sense of the body of normative rules.)

Although the word “right” is not so ambiguous in English as is the word “ius” in Latin (and its counterparts in most Western languages), it is ambiguous.