Free Movement of Legal Sources: The Use of Foreign Sources in Private Law in Europe

Abstract

In this essay, I focus on what kind of legal reasoning and what arguments one may use to legitimate references to foreign sources. Such legitimation is needed when the foreign source is used as an argument with some degree of authority. The typology of arguments that emerges includes reasoning of three kinds. Firstly, the authoritative status of the foreign source may be based on some meta-level authority, for example legislation or conventions that prescribe the use of foreign sources. This, however, is seldom the case. Secondly, the authority of the foreign source can be based on a particular trust in the expertise of those that have created the source. This trust can already be embedded in tradition—then the reasoning lies near the first case—or on substantively based reasons for assuming a superior expertise in the foreign court, foreign author or foreign legal order more generally. And thirdly, the authority of the foreign source may be based on meta-level substantive arguments mainly related to the value of harmonisation of legal orders. Depending on which arguments one uses to support harmonisation—the needs of cross-border trade, the importance of equal conditions of competition, the striving for a European identity or the requirements of justice for and equal treatment of all Europeans—the circumstances in which a free movement of sources seems particularly well-founded are bound to vary. This typology is based on the assumption that not only foreseeability of outcome, but also foreseeability of reasoning matters. A line of reasoning expressly based on an analysis of this type is obviously more transparent than a pure use of foreign sources without any express justification. Transparency of arguments—an open and honest presentation of the arguments used—is a way to enhance equality and foreseeability in a legal world where the ideal of coherent and relatively stable national legal orders is no longer convincing. In today’s complicated and fragmented legal structures this is probably the most one can hope for.