Natural Law is defined by St. Thomas Aquinas as, “Nothing else than a rational creature’s participation in God’s eternal law”. The combination between God’s law and human reason changes the relationship from a subservient role to a participatory.
Vatican II also defines natural law as human beings participating in God’s divine law, by the gentle disposition of Divine Providence, by which he then comes to perceive more increasingly the unchanging truth of God (Gaudium et spes 16-17).