 The ethics of natural law, with its impressive union of the Augustinian theory of eternal principles and the Aristotelian method of moral reasoning, did not remain long unchallenged. Franciscan theologians, John Duns Scotus and William of Ockham, were especially critical of a theory which they considered too restrictive of human freedom. Although Scotus and Ockham never produced treatises specifically devoted to moral theory, the main lines of their critiques may be sketched from their theological works.