Theft is surely punished by your law, O Lord, and by the law that is written in the human heart, the law that iniquity itself does not efface. 11
Catechism number 1959
The natural law, the Creator's very good work, provides the solid foundation on which man can build the structure of moral rules to guide his choices. It also provides the indispensable moral foundation for building the human community. Finally, it provides the necessary basis for the civil law with which it is connected, whether by a reflection that draws conclusions from its principles, or by additions of a positive and juridical nature.