Now and then I realize how much of my writing results from trying to make up for having answered someone’s good question badly.

Thomas Aquinas spends a good deal of time in the Summa discussing whether the detailed precepts of the Old Testament law are all the same kind of thing, or whether, instead, we should say that some of them are moral, some ceremonial, still others judicial – that is, some of them about how to live, some about how to worship, and still others about how to regulate the community.

This may seem like hairsplitting.  One of my graduate students asked me recently what difference it makes whether we get the answer right.  Here’s what I should have said.

Two things depend on getting the classification right, one of them practical, the other theoretical.

The first issue is whether any of those precepts could have been have been different than they were.  Answer:  Some couldn’t, some could; it depends on which kind of precept one has in mind.  None of the moral precepts could have been different, because they reflect general precepts of natural law.  Having created the good of creaturely life, for example, God will not now say “Go murder.”  The wrong of murder is in the nature of the things that He made.

But the ceremonial and judicial precepts could have been different, because they are what are called “determinations” of the moral precepts:  By divine authority, they pin down the precise way in which the moral precepts should be observed, in cases in which more than one possibility may have existed.  Ceremonial precepts pin down the details of our duty to worship God Himself.  Judicial precepts pin down the details of our duties of justice to man in God’s image.

Human law is like this too.  The lawmakers cannot release us from the duty to take care for the safety of others.  On the other hand, they can pin down whether we are to drive on the right or the left.  In much the same way, not even God Himself can release us from the duty to worship Him and Him alone, for the rightness of worshipping Him inheres in Who He Is.  Nor could he release us from the duty to do justice to our neighbors.  On the other hand, some of the details of divine worship and executing doing justice might have been arranged differently than they were.  This is why, for example, it was possible for Jesus to modify the Jewish Passover so that it became Holy Communion, and why we are no longer bound to punish adultery by stoning.  There were good reasons for the old ceremonies and judicial regulations – but by divine authority, certain changes were possible.

By the way, by considering these good reasons for the old regulations, Christians can learn from the ceremonial and judicial precepts of Old Testament law too.  The fact that we are not required to obey them does not mean that we should be indifferent to them.  They were part of the divine pedagogy.

The second issue is why it matters whether we get any definition or classification right.  Answer:  Yes, because the mind uses these things to engage the shape of reality.  Do we wish to understand how things really are, or don’t we?  A dog is not a cat, nor a triangle a rhombus, nor a person, thank God, a thing.  Contrary to the views of postmodernists and some Justices of the Supreme Court, we cannot change the basic structures of reality just by defining them perversely.  At stake is the rational mind’s privilege and calling to know what is

Now at the bottom of what is, we find Eternal Law:  The pattern in the mind of God, by which He created and governs the universe.  Although we cannot know it as His infinite intellect knows it, we can certainly know it through its reflections, by reason in natural law, by direct verbal proclamation in biblical law.  This is how He imparts it to us.

Thus:  Even if there were no practical reason to know how many kinds of

Old Testament precepts there are, it would be worthwhile to know the answer simply because knowing is our vocation.  By doing what we are made for, we give homage to the Author of our minds.

The Blade, The Ear and The Corn

Natural Law and Divine Command

Is Natural Law Really Law?

Does Sola Scriptura [for Protestants] Mean “No Natural Law”?

How the Natural Law Thinker Thinks

Is That Everything?