Abstract

Sin can be seen to be central to the political thought of Thomas Aquinas if the concerns which moved him to the study of matters political are rightly appreciated. Aquinas is primarily concerned, I argue, to determine how good human beings can become by living under political institutions however well structured and thereby to ascertain the limits of natural reason's capacity to effect human moral improvement through the exercise of political power and the arrangement of political institutions. Sin is central to Aquinas' political thought so conceived because institutions appropriate to beings with a tendency to sin foster virtues which fall short of those in which Aquinas thinks the best human life consists. ;Aquinas' political thought is often portrayed as Aristotelian in its emphasis on the sufficiency of natural inclinations to explain the origin and unity of political society. His political thought is often contrasted with that of Augustine, according to whom the effects of sin necessitate coercion to maintain political stability. The importance Aquinas attaches to sin is apparent if he is read as addressing, not the Aristotelian problem of the origins and unity of society, but that of how good persons can become by living under just political institutions. Aquinas argues for the influence of political and social institutions on the character of those who live under them by arguing for the superiority of legal justice to the other virtues which can be naturally acquired. Examination of this argument shows the complexity of Aquinas' relationship to Aristotle: his debt is significant, but there are equally significant departures. ;I argue that Aquinas thinks private property appropriate to political society after the Fall because of the human tendency to sin rather than because Aquinas values liberality and that even justly arranged he thinks it an institution which fosters virtues whose limits he is concerned to draw. These limits are best seen by comparing justice as the institution of private property demands it with the counsels of charity and the voluntary poverty they recommend. Thus human sinfulness limits the virtues whose exercise political institutions demand because of its impact on the institutions which Fallen human beings can sustain