Abstract

Plato’s Socrates holds that we always have reason to be just, since being just is essential for living a happy and successful life. In Book II of Plato’s Republic, Socrates’ main interlocutor, Glaucon, raises a vivid and powerful challenge to this claim. He presents the case of Gyges, a Lydian shepherd who possesses a ring that gives him the power of invisibility. Glaucon’s contention is that Gyges does not have reason to be just in this circumstance, since being just will not promote his happiness. Thus, the argument poses the following challenge: what reason do we have to be just, particularly in circumstances where we can get away with injustice? In this essay, we describe Glaucon’s challenge, highlight its similarity to challenges offered by other skeptical figures in the history of philosophy, namely, Hobbes’ Foole and Hume’s sensible knave, and present three broad lines of response.