A popular citation of Martin Luther King, Jr.’s justly-famous “Letter from Birmingham Jail” is his reference to natural law and Thomas Aquinas:
How does one determine whether a law is just or unjust? A just law is a man-made code that squares with the moral law or the law of God. An unjust law is a code that is out of harmony with the moral law. To put it in the terms of St. Thomas Aquinas: An unjust law is a human law that is not rooted in eternal law and natural law. Any law that uplifts human personality is just. Any law that degrades human personality is unjust.
The Witherspoon Institute has announced today its project, “Natural Law, Natural Rights, and American Constitutionalism,” which “will serve as an online resource center for students, teachers, and educated citizens to learn about the intellectual traditions of natural law and natural rights, particularly within American political and constitutional history.”
The current list of essays by contributors is expansive and impressive, and includes an essay by Acton’s own director of research Sam Gregg, “Natural Law and the Law of Nations.” Be sure to check out this resource from the Witherspoon Institute. I’m eager to see how the site develops and grows. I’m also interested in seeing who will write the currently missing essay (or set of essays) on the Reformation and natural law (including modern Protestantism and natural law). Sigmund’s essay currently covers the period, but much more needs to be said.
Currently the “Early Modern Liberal Roots of Natural Law” primary source section includes Locke, Hobbes, and Montesquieu. This is of course an important stream of natural-law thinking in the early modern era, but hardly the only one and certainly not the only one with later influence.
Additionally, to be of more scholarly use, I think the primary source collection should point toward digitally-accessible forms. I talk about this in the context of theology and economics in an editorial in the latest issue of the Journal of Markets & Morality, “Printed Source and Digital Resource in Economics and Theology” (PDF), and point especially towards the example of the Post-Reformation Digital Library (see, for instance, the pages on Locke and Hobbes).