Tertullian used the adverb naturaliter (naturally) not to characterize the law but rather to describe how it is known. Nature is not the law but the mode of kno wing it. This Latin adverb would eventually find its way into the Vulgate translation of Romans 2:14-15 to characterize what the gentiles know or do without benefit of divine positive law. Thomas Aquinas frequently uses the same term in order t o emphasize the mode of divine promulgation. 19 Natural law is lex indita, instilled in the human mind by God, moving the creature to its proper acts and ends.

Natural Law and Catholic Moral Theology, p. 6