Natural Law, Positivism, and The Antelope

Last week I suggested in this post that the philosophical underpinnings for human rights norms represents a synthesis of positivism and natural law. It embraces the prevailing view that international law is a secular discipline that requires positive evidence for its source material, but also reclaims elements of the Grotian tradition that recognize that in a pluralistic society natural law plays a far more significant and nuanced role in international theory and state practice than is traditionally acknowledged. As a result of that synthesis we currently have a thick layer of positivism that represents the broad corpus of human rights law, and then a thin layer of natural law on top that reflects our highest ideals and norms.

To underscore that point, I wanted to pick up that thread today by discussing an archetypal 19th-century case of international positivism and then extrapolating how that decision might be addressed today. While reading Charles Hobson’s biography of John Marshall, I was reminded of one of his most controversial opinions, the slave trading case of The Antelope. Many of our readers will be familiar with the case. But as summarized in Charles Hobson’s biography, the case represented the one significant opinion concerning slavery and the slave trade decided by the Marshall Court. Here is how Hobson summarizes the case: “By a complicated chain of events, The Antelope, and the Africans, numbering nearly three hundred, were brought into Savannah, Georgia, … for adjudication in the federal court…. The purpose of the appeal was to assert the United States’ claim to all the Africans brought into the country on The Antelope. If this claim was upheld the Africans would be set free and returned to Africa, as provided by various federal statutes prohibiting the importation of slaves and outlawing the slave trade. As Chief Justice Marshall remarked, this case brought into dramatic conflict ‘the sacred rights of liberty and of property’ –the Africans claiming their freedom and the Spanish and Portuguese subjects claiming these same Africans as their legitimately acquired property.” (p. 166-67)

As excerpted below, The Antelope highlights Marshall’s summation of international law obligations as they existed in the early 19th century:

The question, whether the slave trade is prohibited by the law of nations has been seriously propounded, and both the affirmative and negative of the proposition have been maintained with equal earnestness.

That it is contrary to the law of nature will scarcely be denied. That every man has a natural right to the fruits of his own labour, is generally admitted; and that no other person can rightfully deprive him of those fruits, and appropriate them against his will, seems to be the necessary result of this admission….

Slavery, then, has its origin in force; but as the world has agreed that it is a legitimate result of force, the state of things which is thus produced by general consent, cannot be pronounced unlawful.

Throughout Christendom, this harsh rule has been exploded, and war is no longer considered as giving a right to enslave captives. But this triumph of humanity has not been universal. The parties to the modern law of nations do not propagate their principles by force; and Africa has not yet adopted them. Throughout the whole extent of that immense continent, so far as we know its history, it is still the law of nations that prisoners are slaves. Can those who have themselves renounced this law, be permitted to participate in its effects by purchasing the beings who are its victims?

Whatever might be the answer of a moralist to this question, a jurist must search for its legal solution, in those principles of action which are sanctioned by the usages, the national acts, and the general assent, of that portion of the world of which he considers himself as a part, and to whose law the appeal is made. If we resort to this standard as the test of international law, the question, as has already been observed, is decided in favour of the legality of the trade. Both Europe and America embarked in it; and for nearly two centuries, it was carried on without opposition, and without censure. A jurist could not say, that a practice thus supported was illegal, and that those engaged in it might be punished, either personally, or by deprivation of property.

In this commerce, thus sanctioned by universal assent, every nation had an equal right to engage. How is this right to be lost? Each may renounce it for its own people; but can this renunciation affect others?

No principle of general law is more universally acknowledged, than the perfect equality of nations. Russia and Geneva have equal rights. It results from this equality, that no one can rightfully impose a rule on another. Each legislates for itself, but its legislation can operate on itself alone. A right, then, which is vested in all by the consent of all, can be devested only by consent; and this trade, in which all have participated, must remain lawful to those who cannot be induced to relinquish it. As no nation can prescribe a rule for others, none can make a law of nations; and this traffic remains lawful to those whose governments have not forbidden it.

What struck me about the case is how unlikely it would be for Marshall’s line of reasoning to be advanced today, at least with respect to certain universal norms. On an issue such as slavery, international law simply does not speak in terms of pure positivist obligations anymore. Today we would say that even if a state had not consented to the universal norm against slavery and human trafficking in any international convention, and even if a state had steadfastly remained a consistent objector to the norm, that state would nonetheless be bound by the international obligation. We would use the language of jus cogens, but we would be referencing a natural law obligation against slavery.

Regrettably, one can almost apply similar questions to the present age of modern slavery. With respect to slavery, the NGO Free the Slaves estimates that there are approximately 27 million people in slavery today. As discussed here, human trafficking across international borders affects hundreds of thousands of people each year. If a nation attempted to make the case that they had no international obligation to end these practices, the response would not be Marshall’s claim of an inherent sovereign right to engage in slavery or human trafficking, a right which under international law can be divested only by their consent. The response would be that such practices violate universal norms and a state has no choice but to abide by these norms. Thus, the synthesis of positivism and natural law renders human trafficking and slave labor illegal throughout the world.

But then when you get to other norms, it becomes far more difficult. The death penalty, for example, is clearly moving in the direction of abolition. There are strong moral claims against the practice. As noted here, in 1977 only 16 countries were abolitionist, while today 122 countries prohibit capital punishment. But still today a total of 73 countries maintain capital punishment. With respect to the death penalty, you may well imagine an opinion that reads quite similar to Chief Justice Marshall’s in The Antelope. An opinion on the international obligation to abolish the death penalty could well be read to state that “Whatever might be the answer of a moralist to this question, a jurist must search for its legal solution, in those principles of action which are sanctioned by the usages, the national acts, and the general assent, of that portion of the world of which he considers himself as a part, and to whose law the appeal is made. If we resort to this standard as the test of international law, the question … is decided in favour of the legality of the [practice].”

What is the difference? It is that certain norms, such as the death penalty, fall within the thick layer of positivist obligations, while other norms, such as slavery and human trafficking, fall within the thin layer of natural law jus cogens obligations. The real trick is to divine a distinction between universal norms that permit no derogation, and other norms that continue to require state consent.