With regard to such political problems as the form of government and the wisdom of particular public policies, the Treatise has nothing to say. Basic to it, however, is an implied position on the relationship between law and freedom which, if accepted, will profoundly influence one’ conception of the problem of politics. In the Thomistic philosophy of law, human liberty is not an absolute condition. Man exists in the midst of realities which he must recognize and respect if he is to live a human life. He is inherently limited, both morally and physically, by laws that determine the total order of which he is a part. Freedom, or free will, consequently, is the faculty of judging for oneself the demands of reality. As Laversin says: “The autonomy of the individual will can be understood only as an abstraction, that is to say, only by considering man’s power to act as existing independently of his being and the conditions of actual existence.” Law, insofar as it puts into concrete terms the general imperatives of nature, is not an adventitious limiting of action. Rather it is a conscious recognition and corporate specification of the natural boundaries of action in the real conditions of life. Thus law is perfectly compatible with the freedom proper to man.
Stanley Parry, “Aquinas’ Philosophy of Law”, from Treatise on Law (Gateway ed.), pp. ix – x