A satisfactory private law for Europe is not primarily to be sought for in the most common solutions, themselves the result of borrowing. Nor in established rules, themselves the result of longevity, and lack of governmental incentive in innovating. Nor should it be sought in intermediate positions of various mixed systems, themselves the results of the features just above described. Rather it is to be found in the need for authority. This means that a common law for Europe requires the acceptance of a uniform system of adjudicating differences within a standard framework of the necessary sources of law. Authority is paramount, because it alone can constitute the common element. It will not do if, in the absence of immediate pertinent legislation, French courts refer only to the Code Civil and subsequent legislation, and English courts rely on judicial precedents sometimes already several centuries old. Mixed systems will not supply an answer to this need for authority. I wish to exemplify aspects of them by discussion of one instance, the Ten Commandments. My choice of example is dictated first by the extreme importance attributed to the Ten Commandments, secondly by their remoteness from the European Union.