Natural Right without Natural Law: Thomas Aquinas and some important differences with Aristotle

Abstract

The idea of natural right has an ancient tradition that goes back to Aristotle with his concept of "what is right by nature". Thomas Aquinas picks up this idea and enriches it with the contribution of the Stoics and, naturally, of Christianism. A central role in this notion of "what is right by nature" is, obviously, the conception of nature, which has many similarities in the two thinkers. There is, however, an important difference, and it is the one that allows us to make Aristotelian nature the ultimate referent of "what is right by nature". For Thomas Aquinas, on the other hand, nature is an instrument in the hands of God, and thus ceases to be the ultimate referent of all that is "natural", including right. The notion of what is right requires a criterion according to which we say that a thing is just or right, and Thomas Aquinas calls this criterion "law". In things that are right by nature, that law is the reason of God, creator of nature. For Aristotle, on the other hand, since God is neither creator nor voluntary governor of the world, nature cannot be the effect of a creative act, and therefore becomes the ultimate referent for the legitimization of what is right by nature.