a) Are human beings able to fathom both these divisions of natural law?
“Yes, but a single life is not long enough to accomplish this.”
What are a few years for obtaining all that is necessary to make a perfect being, if we only take into consideration the distance that separates the civilized human being from a savage? The longest human life is insufficient for such a task, and even more so when it is cut short, as is the case with such a large proportion of the human race.
Some divine laws govern the movements and relations of raw matter. These laws are called physical laws, and their study is the domain of science. Others concern human beings, themselves, their relations with God and their fellow human beings. The moral laws encompass the rules of the life of the body and those of the soul.