The question is in the title
Based on this excerpt from the CCC
1954 Man participates in the wisdom and goodness of the Creator who gives him mastery over his acts and the ability to govern himself with a view to the true and the good. The natural law expresses the original moral sense which enables man to discern by reason the good and the evil, the truth and the lie:The natural law is written and engraved in the soul of each and every man, because it is human reason ordaining him to do good and forbidding him to sin . . . But this command of human reason would not have the force of law if it were not the voice and interpreter of a higher reason to which our spirit and our freedom must be submitted.55 Leo XIII, Libertas praestantissimum, 597.
I conclude that the church uses “reason” to determine the limits and expectations needed to satisfy the highlighted part of the selections.
1955 The “divine and natural” law6 shows man the way to follow so as to practice the good and attain his end.
6 GS 89 § 1
obeying the natural law leads to: “practice the good” and achievement of our natural end, which is holiness in the presence of our creator.
I suggest the book 50 Questions on the Natural Law by Charles Rice.
You might purchase the talk by Dr. Charles E. Rice from the following website:
It’s only $1 each. The first one really has all the “meat” in it. The second one is relatively short and is just a continuation of the question and answer period, I beleive. Dr. Rice is really an expert and a good listen!
OK! Thanks very much for the tips and book recommendations!