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. (shrink)