The Principle of Sufficient Reason in Ethics: Lessons from Wolff

Abstract

Abstract The principle of sufficient reason (PSR) implies that everything has a sufficient reason. Yet its role in ethics has gone undertheorized. A stark historical exception is found in Christian Wolff, the most influential German philosopher between Leibniz and Kant. I argue that the PSR has indispensable non-normative and normative uses in ethics for Wolff—uses without which ethics would not be possible at all. In sketching these uses, I highlight how Wolff aspires to skirt two Humean challenges. The first concerns how the PSR, which concerns what is, can imply anything about what ought to be. The second concerns how the reasons established through the PSR can be morally motivating. Although hardly unproblematic or uncontroversial, Wolff’s discussion of the PSR in ethics offers both a welcome exception to centuries of undertheorizing and a potential challenge to opponents of the PSR.