Thomas Aquinas (1225–1274)

In his book Visions of Politics , Quentin Skinner proposed that Thomas Aquinas (1225–74) developed a constitutional and legal theory that found an especially congenial home in the northern Italian city-states. This article explores why that should be so. It considers three of Aquinas’s most influential contributions: his Commentary on Aristotle’s Politics ; the De Regno (book 1 of the larger work known as the De Regimine Principum ); and his Treatise on Law ( Summa Theologiae , Ia IIae, qq. 90–97). Particular attention is given to Thomas’s treatment of the forms of government; kingship; tyranny; the common good; and the natural law, especially in its relationship with utility. What emerges is a mixed picture of Aquinas’s theory of government, justice, and law. To be sure, he both profoundly feared tyranny and sought to build safeguards against it; and he developed a conception of the common good that taught that rulers must never pursue their own advantage but only the good of the subjects entrusted to their care. On the other hand, he entrusted too much discretion to legislators and administrators, particularly in the way he articulated his doctrine of natural law.