From what I know, the natural law tradition originates in Greece in ca. 300 BC. Philosopher's of the Stoic school reacted to the break down of the classic Hellenic world. The imperialism of Alexander the Great inundated Greece with a large variety of alien cultural influences. This gave rise to a new concept of law, a trans-cultural law intended to create conditions in which people of the most diverse values and goals, and religious convictions, could live together peacefully and to mutual advantage. In a word: natural law started as a pragmatic effort at productive tolerance. It was neither tied to any particular religious (or at least theistic or Christian) creed - as in the Scholastic tradition - nor was it constructed as a self-contained axiomatic system - which later would become the hubristic ambition of secular rationalistic accounts of natural law.
I have always been sympathetic to the idea that human conduct and interaction are constrained by circumstances some of which can be described as being analogous to natural laws as we use the term in the physical sciences.
Of course, ascertaining and corroborating such laws ought to be an open ended process, and one that should always be amenable to revision and new insight.
Put differently: I have always been opposed to authoritarian or dogmatic accounts of natural law and natural rights.
What do I mean by authoritarian or dogmatic accounts of natural rights? I think of two types, one utterly unacceptable, the other respectable by my personal standards but incapable of scientific authentication or general consensus.
- The first is based on the mistaken notion that natural rights can be logically deduced from certain premises that are true and valid a priori, in the manner of a logical algorithm. This approach ignores the need to establish and probe the subject matter empirically. Unsurprisingly, all efforts to present a self-contained calculus of natural rights can be shown to fail.
- The second approach relies on religious faith. It is perfectly respectable to accept this faith-based grounding of natural rights - as a matter of personal experience. Unfortunately, it cannot be generalised, i.e. it is not possible or even legitimate to expect everybody to share this experience.
So, I have not been able to accept accounts of natural rights that are removed from or insulated against critical debate and scientific challenge and corroboration. I suppose these were the motives for Hayek, a Popperian like myself, to stay away from the corpus of natural rights reasoning.
However, in his important contribution (below), Randy Barnett is right to point out that natural rights may well be conceived in a way entirely compatible with the framework of critical rationalism, the Popperian conception of scientific and intellectual progress, which regards man's fallibility as being his most powerful and beneficial tool, and seeks to expose any theory to critical examination and the possibility of refutation and succession by a better theory.
In addition, Barnett presents the best explanation of the role of prices I have ever come across.