1 “Aristotelian Groundings of the Social Principle of Subsidiarity” Justin M. Anderson, Ph.D. Immaculate Conception Seminary/School of Theology Seton Hall University ABSTRACT: The social principle of subsidiarity, both regarding the federalism debate in North America and the principle’s role in the formation of the European Union, has garnished increased attention in recent years. In this paper I will argue that if one looks for the historical seed of the principle of subsidiarity in Aristotle -- as many authors do -- then attention should fall more properly on his analysis of practical reasoning in Book VI of the Nicomachean Ethics than on Book I of the Politics. The treatment of practical reasoning more aptly explains the need for the principle of subsidiarity and, indeed, averring that it is based on an Aristotelian sense of autonomy is misplaced at best and dangerous at worst. 1. Introduction In the attempt to locate the historical genesis of the principle of subsidiarity, it is not uncommon to begin with reference to Aristotle. The assumption that the best place to look is Aristotle’s Politics would be partially correct, but it does not provide the complete story. In this article I argue that in looking to Aristotle for a historical and philosophical grounding of subsidiarity, one can only adequately establish that notion in Aristotle’s account of practical reasoning in the Nicomachean Ethics. It is not enough to rest this claim on references to self-sufficiency in the Politics. On my way to this judgment, I will be forced to draw the conclusion that one of the leading exponents of the principle of subsidiarity, the French political philosopher Chantal Delsol, has miscalculated the degree to which Aristotle can be helpful. Her approach risks misconstruing the social principle. Such contemporary attempts are disheveled at best, and at worst even dangerous for the very existence of the principle of subsidiarity