It’s the Catholic teaching on morals. It can be found in the Catechism, and it can be found in papal encyclicals and exhortations.
Possessing the cardinal and theological virtues will help someone apply the teachings to their everyday life. Also, having a well formed conscience will help in applying Catholic moral doctrine.
It is primarily found in human nature, written in the conscience of every man, but because man’s nature and intellect are wounded by sin, various points are also revealed directly by God–such as the 10 commandments given on Mt. Sinai–and found in Scripture and Tradition, and handed on by the Church. We use our conscience to apply it in concrete situations in our everyday lives.
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