I have rediscovered by fascination for the old natural law theorists, especially Grotius and Pufendorf. In some of my previous books I mentioned them shortly, but never got around to really invest much time in writing more extensively about them. That can hopefully be corrected in the near future, because I think I finally have an idea why I find these mostly forgotten authors and their theories so interesting.
I wonder whether the so called ‘old-natural law theory’ i.e. the early semi-secular natural law to be found in Grotius, Locke and Pufendorf might not be one of the most influential ethical theories, although it has nearly no official followers anymore and is widely declared dead.
I wonder not just because natural rights are alluded to in so many national constitutions. I wonder because the core idea, namely that nature contains standards of right and wrong comes up again and again in new guises. And there is one simple and fairly convincing reason for this thought to reoccur: If one assumes that standards of right and wrong do not arise out of nature, where else are they supposed to come from? That seems to me one of the reasons why many authors return to some version of natural law, be it by alluding to evolutionary advantages or to alleged neuroscientific claims about the reliability of cognitive processes realised by a particular network of neurons.
An overly simplified description of the development of natural law theory claims that the old natural law, which thinks rights (Grotius) or the law (Pufendorf) to be a part of nature has been replaced by a new natural law theory, which is influenced by the idea that the origin of law can only be found in freedom or in the concept of a law itself. This theoretical perspective, which has been influenced amongst others by Kant is often called rational law. The ratio, or better reason, behind rational law is however not considered to be a natural phenomenon explainable by the natural sciences. The contemporary re-inventions of natural law theory under different named seem to put exactly this latter claim into doubt. Even if there were something like a rational law, this rationality itself – so it is thought – is a part of nature and as such open to explanation within the natural sciences.
Obviously, nobody pursuing a naturalist account of law or ethics nowadays refers back to Grotius or Pufendorf. Still I’m curious, whether there is a sufficient similarity in the theoretical approaches of then and now, in order to learn something from old natural law for modern naturalist theories of ethics.