It occurs to me that there is a resurgence of interest in the classical legal tradition, in part because of @iusetiustitium and the works of @Vermeullarmine, @josias_rex, but little understanding of the schism between classical natural law and new natural law.

A short thread./1

The champions of NNL are well known: John Finnis, Germain Grisez, Robert George, Mark Murphy, Jonathan Crow to name a few. Their project aimed at establishing a series of principles of practical reasonableness to order human life and human community “independent of God.” /2

NNL holds that law is necessarily a rational standard for conduct, per Murphy. NNL comes in strong and weak versions, the internal debates are fascinating: the strong holds rational defect to render a norm legally invalid, while the weak considers the norm legally defective. /3

Classical NL reads instead from Aquinas that normativity is built into the very fabric of reality, meaning that metaphysics necessarily underlies law. Teleology and essentialism then cannot be taken out of the equation, and the subject of law is part of a whole. /4

The first critique of NNL was Francis Hittinger with his 1987 book "A critique of the new natural law theory” but he was quickly rectified in his understanding, rather convincingly by @McCormickProf in a 1988 review of the same book. Both are worth reading. /5

Then David Oderberg published in 2010 an essay in an edited book “The Metaphysical Foundations of Natural Law” to explain the changes from classical NL to NNL through metaphysics, teleology and essentialism. He explains how NNL differs from Aquinas’ original understanding. /6

In 2013, Steven Long followed with an essay “Fundamental Errors in New Natural Law Theory” in which added to the conversation in which he disagrees with @McCormickProf’s response and identifies the five root errors of NNL. Oderberg is not named, but it builds on his works. /7

For a recent critique of NNL, underlying the new SCOTUS decision in Bostock vs. Clayton, one can look at James Berquist’s entry on @josias_rex here: https://tinyurl.com/y6tfdvqx . This is pretty much all there is for now, but I plan on adding to this discussion very soon. /8

(Thread inspired by @ANNVYSHINSKY and @McluhanG, so thank you.) 9/9

Addendum: the first critique of NNL was brought forth by Ernest Fortin in 1982 in his "Review: The New Rights Theory and the Natural Law" to which, Finnis responded while praising it in 2015's "Grounding Human Rights in Natural Law"

Thanks to @erikabachiochi for pointing it out.