Examining the history of the concept of free will helps distinguish metaphysical issues beyond the interest of a court of law from considerations about the nature of human action germane to legal reasoning. The latter include Plato's conception of the rational governance of the soul and Aristotle's conception of voluntary action, both of which arose before Hellenistic philosophers propounded analogues of modern positions against determinism (Epicureans) or for the compatibility of free will and determinism (Stoics). The concept of will itself also has a history, being first conceived as a distinct power by Augustine. Modern physics raised new problems about free will, as human motivations began to look less like rational perceptions of the good and more like mechanistic causes. Contemporary philosophy has not solved the problem of free will but has spun off analyses of the nature of action and moral responsibility that are of interest for legal reasoning. Copyright © 2007 John Wiley & Sons, Ltd.