Excerpt from the book Mediations on Christian Dogma, Volume II - The natural moral law, rooted in God's Eternal Law, is an innate light in human consciousness, guiding rational creatures toward moral goodness and distinguishing them from animals driven by instinct alone. This universal law, as described by St. Paul, is evident even in those without formal divine revelation, as conscience applies it to specific cases, accusing or defending actions. Unlike human laws or customs, this absolute moral standard is unchangeable by human authority, and while moral sense may be corrupted temporarily, the conscience, aided by divine providence and the consequences of actions, ultimately discerns true morality. Though individuals' understanding of this law is imperfect and evolves over time, shaped by habit, culture, and progressive revelation, humans have a duty to promote divine moral principles, fostering virtues like truth, honor, and uprightness in the world.