Subsidiarity is a:
Subsidiarity is related to human freedom. “Undoubtedly the principle of subsidiarity [is] an expression of inalienable human freedom. Subsidiarity is first and foremost a form of assistance to the human person.” (Caritas In Veritate, 57)
The principle of subsidiarity is derived from the nature of human dignity, which demands, first, the maximum participation of people find solutions to their own problems and, second, the maximization of human initiative as naturally expressed through all kinds of associations and organizations contributing to the common good.
The principle of subsidiarity recognizes that subsuming this human participation and human initiative in increasingly higher levels of government actually violates the dignity of the human person and inescapably undermines the common good. Therefore, the involvement of higher levels of government is to be deliberately minimized, restricted to serious problems irremediable by other means, and brought to a halt when the necessity of higher level involvement no longer exists—either because the need has disappeared or because a way to meet it at a lower level has been found.
Put simply: Problems are best solved at the level they arise.
“We do not need a state which regulates and controls everything...” (Deus Caritas Est, 28)