A stable union of individuals or groups morally bound to each other, who cooperate to achieve a common goal or good under the guidance of some structure of authority. 

Imperfect Society.— A society that, in some regard, lacks what is required to achieve the full flourishing of its members and is, therefore, naturally ordered to higher, more perfect societies. 

Perfect Society.— A society that possesses all the resources that are required to achieve its common good and that, therefore, is not naturally ordered to a higher society and, because of this, is self-governing.  In the order of nature, this is the political community; in the supernatural order, this is the Church. 

Natural Society.— A society to which human beings are ordered by their very nature, for the sake of survival and perfection as moral and cultural agents. 

Supernatural Society.— The society that (in the present and final age of salvation history) is the Church, founded directly by God in which human beings are incorporated, respecting the limits of human nature and the sublimity of divine communion.  Classically, the relationship of supernatural society to natural societies is understood as involving merely indirect authority of the former over the latter. 

Conventional Society.—Various freely instituted societies which pursue particular goods that have some relation to the natural societies of family and the political community (e.g., service organizations, arts councils, etc.), as well as the supernatural society of the Church (e.g. sodalities, etc.)