The word subsidiarity is derived from the Latin word subsidiarius and has its origins in Catholic social teaching. The concept or principle is found in several constitutions around the world (see for example the Tenth Amendment to the United States Constitution).
It is presently best known as a fundamental principle of European Union law. According to this principle, the EU may only act (i.e. make laws) where member states agree that action of individual countries is insufficient. The principle was established in the 1992 Treaty of Maastricht, and is contained within the proposed new Treaty establishing a constitution for Europe. However, at the local level it was already a key element of the European Charter of Local Self-Government, an instrument of the Council of Europe promulgated in 1985 (see Article 4, Paragraph 3 of the Charter)
The principle of subsidiarity was developed in the encyclical Rerum Novarum of 1891 by Pope Leo XIII, as an attempt to articulate a middle course between the excesses of laissez-faire capitalism on the one hand and the various forms of communism, which subordinate the individual to the state, on the other. The principle was further developed in Pope Pius XI's encyclical Quadragesimo Anno of 1931, and Economic Justice for All by the United States Conference of Catholic Bishops.
Since its founding by Hilaire Belloc and Gilbert Keith Chesterton, Distributism, a third way economic philosophy based on Catholic Social teaching, upholds the importance of subsidiarity.
Subsidiarity was established in EU law by the Treaty of Maastricht, signed on 7 February 1992 and entered into force on 1 November 1993. The present formulation is contained in Article 5 of the Treaty Establishing the European Community (consolidated version following the Treaty of Nice, which entered into force on 1 February 2003):
The Community shall act within the limits of the powers conferred upon it by this Treaty and of the objectives assigned to it therein.
In areas which do not fall within its exclusive competence, the Community shall take action, in accordance with the principle of subsidiarity, only if and in so far as the objectives of the proposed action cannot be sufficiently achieved by the Member States and can therefore, by reason of the scale or effects of the proposed action, be better achieved by the Community.
Any action by the Community shall not go beyond what is necessary to achieve the objectives of this Treaty.
A more descriptive analysis of the principle can be found in Protocol 30 to the EC Treaty.
Article 9 of the proposed European constitution states
Under the principle of subsidiarity, in areas which do not fall within its exclusive competence the Union shall act only if and insofar as the objectives of the intended action cannot be sufficiently achieved by the Member States, either at central level or at regional and local level, but can rather, by reason of the scale or effects of the proposed action, be better achieved at Union level.
Formally, the principle of subsidiarity applies to those areas where the Community does not have exclusive competence, the principle delineating those areas where the Community should and should not act. In practice, the concept is frequently used in a more informal manner in discussions as to which competences should be given to the Community, and which retained for the Member States alone.
The concept of subsidiarity therefore has both a legal and a political dimension. Consequently, there are varying views as to its legal and political consequences, and various criteria are put forward explaining the content of the principle. For example:
The European Union, however, has as part of its phraseology a call for "an ever-closer union." What restraints upon the progress of centralised decision making would be brought about by strict reference to the principle of subsidiarity have yet to be proven by major constitutional clashes.