Back to Basics: The Reawakening of Natural Law

In response to Will Fettes’s thoughtful comment: The problem is not with positivism per se but positivism alone. By the 1960s, certainly in the United States there was a view that only positive law theory explained law and positive theory relied on the existence of the usual legal institutions—with their absence on the international plane, positivists could not understand how international law could have authority, be created, etc. International law hardly seemed to be real law. Its existence might extend as far as the president’s consent but not beyond and that consent could be withdrawn. American legal theorists could hardly conceive of (and the torture memos do not mention) jus cogens or peremptory norms.

By contrast, the vast majority of international lawyers accept that there is a category of peremptory norms, norms that may not be changed by treaty. These norms are demonstrably not norms created by positive acts and are powerful evidence that aspects of international can only be explained through natural law theory.

In Power and Purpose, I present other evidence of the importance of natural law to international law: the basis of international law authority and important general principles of international law such as good faith and proportionality. International law has always had some hardy scholars who were never too shy to write about natural law, but too often, we have only whispered about it, accepting the need for it to explain jus cogens or general principles, but, always hoping not to appear less scientific than our domestic law colleagues.

Stephen Smith’s account in Law’s Quandary of the crisis in domestic jurisprudence may be freeing domestic legal theorists to accept the role of natural law theory in grounding domestic legal authority and the higher norms of domestic law. His book may free international lawyers, too.

In addition, the post-modernists have challenged us to move beyond the fetters of materialism and the application of Enlightenment scientific method even to our ideational constructs such as law.

This is not to say it is all natural law. In my view, natural law explanations account for some essential aspects of law but natural law theory from Aquinas forward has always recognized that most of the law is positive law. And as I describe in the book, the higher norms are most reliably found when authoritative courts and tribunals look to evidence in the common law for what the community’s higher norms are. I do not see concepts such as the “common good” as more than inspirational—the common good concept is far too limited by subjectivity to be a reliable source of universal law.

Natural law is essential to both provide an explanation of legal authority and the outside governor on the positive law. Where I believe the work of theory needs to go next is in developing a richer theory of international legal process for identifying and applying jus cogens and general principles.

In the next post, I will discuss the jus cogens prohibition on aggression and show how the authoritative processes of international law are best means of clarifying the dimensions of this norm.