Natural and Squishy?

Ask me to sit down and write a 700-word blog post, and I may do it, but it will take me far too long and I’ll fret about what to say.

Raise the right question or argument on Twitter, and I’ll have you 700 words at 6:30 AM.

Yesterday, I saw a tweet asking for the best arguments for a natural law perspective over theonomy, and in the replies I ran across this complaint:

My main issue is that compared to theonomy it [natural law] seems like a rather vague and blurry concept where whichever of God’s laws someone likes they count it natural law.

Since natural law is one of my favorite hobbyhorses, I replied with the following wall of text (slightly edited now),1 which I hope will prove perhaps generally useful for other people thinking through Christian ethics and the merits or demerits of natural law theory:

It is true that people do just pick whatever laws in the Old Testament they like as part of “natural law” (though I think there are ways theonomists pull off the same basic thing at times).

That said, even the wording “God's laws” here begs the question in favor of theonomy, insofar as it implicitly treats the Torah as simply God’s laws without qualification, rather than as a set of laws God gave to a particular people for particular reasons.

That said, the “vague and blurry” appearance to natural law argument derives only from the fact of the vagueness and blurriness of life under the sun itself, insofar as it is not always clear what is good for man. The basic idea has nothing ambiguous about it:

• God made man with a given design for given purposes.

• Man's universal moral obligations consist in working with that design for those purposes.

• Except for things pertaining to the supernatural economy beyond any possible human power (e.g. redemption and glorification), we can perceive the design and purposes of man as we do other natural things, e.g. that birds are meant to fly, or that the sun is meant to warm the earth, or that reproductive systems are meant to produce offspring, or that hearts that don't beat aren't doing what they're made for.

Since man is a rational and social animal, we can also identify the main areas in which we can follow the design:

• Physical: Most people agree easily enough we can identify what is good for the body by natural reason, as most humans historically have done easily (though there are here and there movements of wackos who throw this off).

• Social: While there are many disagreements between people about what the perfect society would look like, all can easily perceive that man's social design is best fulfilled when people are happy with each other and not in conflict, but are rather able to unite for each other's benefit.

• Rational: While there are many disagreements about what a perfect mind would think, all men easily perceive that a perfected mind will think the truth, reason correctly, remember accurately, etc., etc.

The “vague and blurry” parts begin once we start asking what actually helps us get to the things everyone knows we are made for in each of those categories.

For physical health, what lifestyles are best, and do we want seed oils or GMO stuff or a carnivore diet or something else?

For social life, will people be happiest and least in conflict and best at helping each other in a society with more or less diversity, with more or less equality, with or without money and industrialism, etc.?

For the rational life, what things are actually true? How we train minds to reason correctly and remember accurately?

Natural law theories are willing to grant that you can figure out the answers to many of these questions by paying attention to How Stuff Works, by watching people and societies, by studying history and biology and the lives of your good, bad, or ugly neighbors. Not everyone will be equally good at doing it, and in some areas it will be hard work to fish out the truth and even harder work to prove it, but the information is there to discover by such means.

But you can also answer some of these questions by looking at the Torah, since God knows all the answers and certainly gave the Jews laws agreeable to how He designed mankind. Yet what the natural law theorists (and basically the entire Church) reject is that these laws were given as law to anyone but the Old Testament Jews directly, and further that every single law contained within necessarily implements man's good in a way that is best for any human at any time in any set of circumstances, rather than simply being the best possible laws for the Jews at that time given their social, political, redemptive-historical, technological, and other conditions.

To answer your original question about best arguments, there are two good books I like to recommend on the matter:

Hooker is good for the theory and principles of law in a concise and easy-to-follow argument, while Hemmingsen is good for showing how the nuts and bolts of natural law argument should operate, ideally as actual logical demonstrations rather than loosey goosey vibes.