When considering the most significant and influential concepts in American political thought and history, Thomistic natural law does not readily spring to mind. While the idea of natural law does appear on the landscape in a couple of crucial places—Jefferson’s reference to the “laws of nature” in the Declaration of Independence and Martin Luther King, Jr.’s discussion of the “moral law” in his “Letter from a Birmingham Jail” among them—this idea always seems, when viewed from the broad perspective of the history of American political thought, to be playing a cameo rather than a starring role. This may be partly due to the fact that the much more central American idea of individual natural rights is often perceived to be in serious tension with Thomistic natural law—the former emphasizes the individual while the latter emphasizes the community.
It may come as a surprise, then, to notice that the defining intellectual moment of American political thought and history—our struggle with race-based slavery—was, in fact, premised largely upon an implicit marriage between the idea of individual natural rights and Thomistic natural law. As Frederick Douglass had hoped, America became “exceptional” by overcoming its uniquely egregious moral failures, and in doing so advanced an idea of natural morality that went beyond both “ancients” and “moderns.”
Natural Law and Eternal Law
For St. Thomas, understanding the natural law begins with understanding the eternal law, since the natural law is defined as our “participation” in the eternal law; and the eternal law is simply the idea of the governance of things in the mind of God. How, then, can we “participate” in this Divine idea? Most plausibly and simply, by governing the things within our limited sphere of control in accordance with our knowledge of the world God has made. As St. Thomas explains it, “every knowledge of truth is a kind of reflection and participation of the eternal law,” since the possession of knowledge indicates that we have an idea about something in our minds that matches up with the idea God had in mind about this same thing when He created it. By knowing the world, then, and ordering ourselves in accordance with this knowledge, we participate in the knowledge that gave rise to the world in the first place. Obeying the natural law is, in this way, a human analogue of the Divine act of creation: we should act as God created, in accordance with our ideas about the world.
The most immediately relevant knowledge we can have, then, consists in the knowledge of what it is to be a human being. This is why St. Thomas provides the general ordering of precepts of the natural law according to the order of our natural inclinations. This order is not just a serial order but a hierarchical one, and one that mirrors the analysis of human nature given by Cicero and Aristotle in defining a blueprint for good and virtuous human action. The overall point of St. Thomas’s discussion of the natural inclinations is that human nature contains a hierarchical blueprint for action within it, and this blueprint commands action in accordance with reason as our highest and distinguishing feature.
This description of the natural law explains why St. Thomas doesn’t give us anything approaching a definite table of precepts. It also explains why the only universally applicable precept he does provide is the general one to do and pursue whatever practical reason apprehends as good. What the natural law commands is simply to do the opposite of what one hears so often these days—to do not what one “feels” as if one should do, but rather what one “thinks” one should do. The natural law absolutely commands action on the basis of reason rather than the passions or emotions, and the action that is based on reason is the one that harmonizes with one’s best understanding of the context within which we live and act, which was created according to ideas in the mind of God, or the eternal law.
In this way, St. Thomas’s definition of the natural law is remarkably consonant with Locke’s simple identification of the law of nature with “reason” in the Second Treatise, and also has a similar connection with the fact of divine creation. Both Locke and St. Thomas agree that it is our common humanity or human nature that provides the foundation for the natural law. What is absent from St. Thomas’s account is the substantial focus on natural rights and self-ownership that Locke grafts onto the natural law, a focus that seems to undermine the idea of natural law along the lines of Machiavelli and Hobbes—that is, until Locke’s distinction between the humanity and unique selfhood of the individual comes to light.
If we can appreciate the moral consequences of one’s uniqueness as an individual without denying the moral consequences of our common humanity, we may be able to follow Locke’s cautiously staked-out path into the modern world without abandoning the wisdom of St. Thomas or Aristotle.
American Exceptionalism and Race
This distinction between the humanity and the unique selfhood of the individual can clarify and substantiate what is true in the modern preoccupation with the individual while persuasively discrediting what is false. It can also connect the truth of individual human dignity to the truth about the vast and morally significant context within which the individual exists. This has been, in an important sense, a distinctive task of American political thought from its beginning up to the present. It appears most clearly in our historical struggle with the issue of slavery.
As Frederick Douglass persuasively argued, the controversy over slavery constitutes the best argument for American exceptionalism—the idea that the United States has a special, God-given mission in the world. As Douglass said in his speech on the Dred Scott decision, “The American people have been called upon, in a most striking manner, to abolish and put away forever the system of slavery.” The slavery issue plagued the American founding, tarnishing the original Constitution and leading directly to the Civil War. As Lincoln said in his debates with the other Douglas, “the real issue” at hand in the sectional conflict that precipitated the Civil War was simply whether or not slavery should be viewed “as a wrong.” The centrality of the slavery issue to American political thought and history is significant because the primary weapons that were wielded against it were not the rifles of the Union army but, rather, an idea of natural morality.
At another place in Douglass’s speech against the Dred Scott decision, this connection to natural morality begins to become evident:
The Supreme Court of the United States is not the only power in this world . . . Judge Taney can do many things, but he cannot perform impossibilities . . . He may decide, and decide again; but he cannot reverse the decision of the Most High. He cannot change the essential nature of things—making evil good, and good evil. Happily for the whole human family, their rights have been defined, declared, and decided in a court higher than the Supreme Court. “There is a law” . . . “above all the enactments of human codes, and by that law, unchangeable and eternal, man cannot hold property in man.”
The synthesis of remarkably traditional and Thomistic natural law thinking with recognizably modern and liberal natural rights thinking in Frederick Douglass’s statement here is uniquely enabled by a particular feature of the abolition movement, a feature embodied in an especially intriguing way in Frederick Douglass himself: namely, that this movement, unlike other significant ones in American history such as the Revolution or even the later civil rights movement, was instigated by an assertion of rights on behalf of others.
Defending the Humanity and Natural Rights of Others
This characteristic of the anti-slavery movement required the placement of the idea of natural rights found in the Declaration of Independence—and in Locke—within the traditional idea of natural law, since the possession of subjective natural rights had to be recast as an objective fact about human nature in order to be applied to others in this way. Lincoln, Frederick Douglass, William Lloyd Garrison, and others didn’t argue for the natural rights of slaves on the basis of the natural rights of non-slaves, simply extending or universalizing their own natural rights to include them. Rather, they argued for the natural rights of slaves on the basis of the slaves’ humanity or the fact of their participation in human nature.
This is a crucial point for two reasons. First, because a common critique of the modern idea of natural rights focuses on the egoistic self-assertion it is often associated with, the anti-slavery movement’s non-egoistic assertion of others’ natural rights provides a prominent counter-example. Second, the abolitionists’ arguments for the natural rights of slaves on the basis of the slaves’ human nature stand as a clear alternative to the way in which contemporary “human rights” are usually derived: namely, from the self-interested universalization of one’s own egoistic assertion of rights. Such contemporary tactics rest on the notion that if I want my assertions of rights respected by you, it makes sense for me to respect yours in return. By separating natural rights from egoism and utility, and attaching them instead to a conception of human nature, American anti-slavery arguments showed how a reconciliation between modern natural rights and medieval and ancient natural law might be achieved.
In these arguments, the same Lockean natural rights that arise individually through one’s self-ownership were explicitly conceived as an objective, observable fact about the wider context within which every individual exists. Hence, they were understood as relating to the medieval Thomistic natural law. In this way, the issue of racial slavery drove American political thought implicitly toward the very doctrine of natural rights and the natural law that I attempt to render explicit and defend in my recent book on the foundations of natural morality.