Rational choices in classical Greek thought

The paper focuses on Plato's (Republic book 2) restatement, via the thought experiment of “Gyges and the ring,” of an ancient Greek “folk theory” of practical reasoning – a coherent account of human deliberation, choice, and action that deductively yields explanations and predictions about behavior. The theory bears a family resemblance to contemporary theories of rational choice, in its motivating intuitions and in the habit of illustrating abstractions through fanciful stories and historical narratives. It assumed that a rational agent would have ordered preferences over outcomes, beliefs about the state of the world, and would act accordingly, based on expectations of desire satisfaction. Plato’s thought experiment of is based on an anecdote in Herodotus’ Histories (book 1) describing how Gyges became king of Lydia. Plato’s account, concerns unconstrained choice and is modeled by a simple decision tree. Herodotus’ earlier story, lacking the conceit of an invisibility ring, emphasized the constraints on individual desire satisfaction that arise from others’ choices; it can be modeled as a three-player game in extensive form.