Subsidiarity is a principle of social organization that originated in the Roman Catholic church, and was developed following the First Vatican Council. It has been associated by some with the idea of decentralisation. In its most basic formulation, it holds that social problems should be dealt with at the most immediate (or local) level consistent with their solution. The Oxford English Dictionary defines subsidiarity as the idea that a central authority should have a subsidiary (that is, a supporting, rather than a subordinate) function, performing only those tasks which cannot be performed effectively at a more immediate or local level. The concept is applicable in the fields of government, political science, neuropsychology, cybernetics, management and in military command (Mission Command). In political theory, the principle of subsidiarity is sometimes viewed as an aspect of the concept of federalism, although the two have no necessary connection. The principle of subsidiarity plays an important role in the political rhetoric of the European Union concerning the relationship between the EU governing bodies and the member states.