The divine-like power of rulers to move the will as an internal principle (ST I-II.93.5)

The Eternal Law, part 5

For Aquinas, then, one of the political functions of his otherwise theological concept of eternal law is that of limiting what it is that human law is actually able to accomplish in directing human action to its end, which it does principally by permitting certain types of action that do not conduce to that end and yet which human law is not allowed to prohibit. That having been said, Aquinas also posits an important parallel between human and eternal law, namely that just as by his eternal law “God imprints on the whole of nature the principles of its proper actions,” so likewise a ruler is able to “impress” and “imprint” on the minds of his subjects an “inward principle of action” (ST I-II.93.5). This is significant, for as it was noted earlier, Aquinas distinguishes human actions into, on the one hand, those that are voluntary, being moved by an inward principle of the will’s own natural inclination towards the act in question, and hence are actions in the proper sense; and on the other hand, those actions that are involuntary, being violently compelled by an external force to act in a way contrary to the will’s own command. Here, by contrast, Aquinas supplements this division of things by introducing a third possibility, namely that of an external ruler being able to use the coercive power of law and its threat of punishment to move the will from within according to its own internal principle of natural inclination. Earlier Aquinas set himself the challenge to argue that God, by virtue of his transcendence and universal causality, was alone able to act on the will of man according to its own inclination in a way that did not render its actions involuntary. Yet here Aquinas would seem to suggest that this same power is now also shared by the political ruler. Where Aquinas had only a moment ago confessed the radical limits of human law in its inability to direct human action to the extent that God in his eternal law could do, curiously, and seemingly inconsistently, he now gives human law much the same prerogative and power as God’s eternal law.