Subsidiarity in Private Law

Subsidiarity which constitutes a leading principle of European Union law has also its place in private law. It is a functional notion that can only be comprehended through its applications, the search of the place that it occupies in private law passes through analysing the various functions which it has. It is an autonomous notion which has to be distinguished from close situations where there's a concept that is elaborated according to another one said to be principal or primary. It has to be for instance distinguished from the links existing between the principal and the accessory, from suppletivity and from equivalence. Revealed and known as a characteristic of the legal action of enrichment without just cause, it has spread to various topics of private law. In private law subsidiarity performs two functions: the first one aims to preserve the primacy of the principal, and the second one, aims to assure the substitute of the principal. Its first function is illustrated by the obligation of the guarantor, by the obligation of the partners for the liability of debts in civil companies and other assimilated societies, and also by the subsidiarity of the enforcement proceedings, more precisely, the one related to the seizure of goods. In addition to these illustrations related to substantive law, subsidiarity is also illustrated in civil procedure; it is the one which is revealed to the course of the process. Its second function is illustrated by the legal action of enrichment without just cause, as of a subsidiary legal action, and by the nullity recourses, as of subsidiary remedies at law, and also by the subsidiary vocation of the common law, illustrated by the common rules of civil liability. Subsidiarity is employed to avoid any subversion of the legal order. It contributes to fill the gaps of Law and to make the legal system more efficient.