Abstract

This article asks how we should understand the maxim liber est causa sui when we encounter it in the writings of Thomas Aquinas. The maxim – most easily translated as “the free is the cause of itself” – is taken from the first book of Aristotle’s Metaphysics,and Thomas uses it when he needs to show that something, or someone, is free. The first section of this paper shows that Thomas does not intend us to understand the maxim as indicating self-creation: as he himself often says, Nihil est causa sui. The second part of this paper argues that Thomas intended us to understand something more than agent causality or acting “from oneself” when he cited this maxim. Thomas’s meaning when citing this maxim includes Aristotle’s meaning in writing it, and Aristotle did not primarily mean that the free being caused itself to act. Instead, he meant that the free being acted for the sake of an end that was its own – it acted “for its own sake.” Passages in which Thomas cites the maxim – particularly De veritate 24.1 – must be understood to include two senses of causa sui. When Thomas applies the words causa suito something, he does not simply mean that its actions are from itself or a se; he also intends to signify that its actions are “for its own sake” or propter se.