Subsidiarity

Subsidiarity is the principle that decisions should be taken at the lowest level competent to take them, and that higher levels of authority intervene only to assist lower ones, never to absorb their functions. The canonical formulation is Pius XI's 1931 encyclical Quadragesimo Anno, which described it as a "grave evil" for a larger and higher association to arrogate to itself functions a smaller and lower one can perform.

The principle has had two distinct careers in the twentieth century. In Catholic social teaching it became the counterweight to both totalitarian centralisation and unregulated individualism — a defence of the family, the parish, and the voluntary association as the natural locations of human flourishing. In European Union law it was adopted in the Maastricht Treaty (1992) as a constraint on the central institutions: the Union acts only where objectives cannot be sufficiently achieved by member states. The EU version has been honoured more in rhetoric than in design, but the legal text preserves the idea.

For the parallel society, subsidiarity is the political-theory cousin of heterarchy — the same instinct expressed in the language of governance rather than systems. It explains why nested voluntary associations, polycentric legal orders, local currencies, and federated protocols are not merely tolerable alternatives to centralised power but the natural form of a free society. It is also the cleanest answer to the objection that decentralisation is a slogan rather than a doctrine: subsidiarity says decentralise to the level the work can actually be done at, and no further.