A Metaphysics of the Common Good

Thomist and non-Thomist political theorists alike often invoke “the common good” as an overarching standard governing the prioritization of private goods and even which comprehensive doctrines may participate in the public square of pluralist societies. Such invocations, however, place strict but little-noticed constraints on what “common” can mean. This paper makes explicit Aquinas’s latent metaphysics of the common, and in doing so explicates the composition relation between human citizens and the natural complete societies. This unique parthood metaphysics, called composition by Order as Sustaining End (drawing on earlier work on substances by Robert Koons), resolves Maritain and Eschmann’s worries that treating citizens as material parts amounts to totalitarian domination of human persons. It also shows why Thomists should give priority to the distinctive conception of the common good over instrumental and aggregative conceptions. Non-Thomist social ontologists are challenged to provide a parallel conception adequate to their quite similar political requirements.