Aquinas and Human Rights

Aníbal Sabater is a lawyer in New York City specializing in international arbitration.


Whether subjective rights in general and human rights in particular exist in the classical legal tradition is a vexed question that most contemporary Thomists answer in the negative.   In 2019, however, Fr. Dominic Legge OP, Director of the Thomistic Institute, published “Do Thomists Have Rights?,”[1] an article of some popularity in integralist circles that presents Aquinas as a human rights forerunner.[2]  These lines are offered in a spirit of constructive criticism of that article.

The gist of Fr. Legge’s position is as follows:

1.       For Aquinas, justice is a reasoned order to the common good, and “ius” (right) is the proper object of justice. 

2.       Aquinas ascribes different meanings to “ius” as the object of justice.  “Ius” can be the thing or the conduct that is due to another (this is the objective meaning that most Thomists embrace) but it can also mean subjective right (i.e., the power to claim something from another). Every now and then Aquinas even uses “ius” as synonym for natural subjective right (for instance when he asserts that “patria potestas” is a faculty that exists “de iure naturali”).

3.      Insofar as an object of justice, subjective rights must be ordered to a good and have an “external” existence, meaning that they cannot depend on the characteristics or intention of the person required to honor them.  For Aquinas, the external reason why subjective rights exist is that their holders are possessed of self. 

4.       Later authors like Francisco de Vitoria, Domingo de Soto, and Bartolomé de las Casas[3] drew from Aquinas’ categories to develop a human rights theory to curb the power of the Spanish crown over American natives.  On that theory, men, as free and rational creatures, enjoy inalienable rights that order them to God.

4.       Over the years, however, the focus shifted, and under the influence of William of Ockham and Francisco Suarez, human rights came to be treated as unfettered spheres of human freedom, no longer tied to a reasoned order, but rather to the will of the lawgiver.  This “absolutized” view of human rights, which promotes individual fulfillment rather than the common good, has been adopted as part of the “American project” and is a poison pill that threatens to destroy it from within.

Thus Fr. Legge. 

While accurate and well-reasoned on many points (especially his diagnosis of Ockham and Suarez’s shaping of modern human-rights theory), Fr. Legge’s account omits a key distinction between the meaning Aquinas ascribes to “ius” in general and the specific meaning he ascribes to “ius” as the object of justice. 

Fr. Legge is right that Aquinas uses the term “ius” in a variety of contexts, sometimes equating it with “potestate vel facultate” (a power or a faculty—or in modern terms, a subjective right).[4]  However, when Aquinas says that “ius” is the object of justice, he is using “ius” as the very thing or conduct that is owed.   This is especially clear in S.Th. II-II, q. 58, a. 11,[5] where Aquinas concludes that the proper act of any type of justice (legal or particular) is “nothing else than to render to each one his own.” (“Et ideo proprius actus iustitiae nihil est aliud quam reddere unicuique quod suum est.”)   He also explains there that, “the matter of justice is an external operation insofar as either it or the thing we use by it is made proportionate to some other person to whom we are related by justice.” Accordingly, deciding whether something is due is not an act of justice per se.  Justice requires the actual giving (or performance) of the thing that is due. 

This is why subjective rights are not the object of justice.  The seller of a house has a subjective right to receive the price, but the positive law that declares that right is just an act of legislative (or regnative) prudence by the sovereign.  For justice to take place, the buyer must actually pay the price, or in the alternative, the judge in virtue of his coercion, must obtain from the buyer and transmit to the seller funds sufficient to pay the price.  Similarly, a legislative declaration that cruel and unusual punishment shall not be inflicted, is proper to the virtue of prudence, but is not an act of justice because it does not result in a tangible giving to a concrete person.  However, the judge  who applies that declaration to move an inmate from extended solitary confinement to a common prison cell  is doing an act of justice to the extent he is giving the inmate his due.

Ultimately, while Aquinas contemplates the existence of subjective rights, he sees them as a tool to arrive at justice, not as the end or object of justice itself.[6]

In circumscribing the object of justice to the actual giving of the thing owed, Aquinas follows Roman law, Aristotle and Isidore, and avoids two traps that haunt modern legal systems, namely monism and formalism.

Monism focuses on subjective rights at the expense of the obligations that are the reverse of those rights.[7]  Think, for instance, of Article 1(1) of the International Covenant on Civil and Political Rights, which baldly asserts that: “All peoples have the right of self-determination. By virtue of that right they freely determine their political status and freely pursue their economic, social and cultural development.”  The statement may sound well, but whom does it bind and to what? Does this provision establish an obligation for a government not to interfere in foreign civil wars? Does it establish an obligation for the government to let certain “peoples” within its territory choose their political status? Does it do both things, or perhaps none of them?

With its disregard for obligations, monism fosters a culture of individual entitlement, as opposed to one of respect for others and work towards the common good. The classical legal tradition quite often operated the other way around—setting out precise obligations from which subjective rights and common good goals could be inferred.  For example, Spain’s 16th and 17th Century Leyes de Indias—which Fr. Legge rightly ascribes to the influence of Vitoria and his school—codified the obligation of Spanish explorers to not take sides or meddle in internal wars between native American populations.[8] The implied corollary of that obligation was a native right to live free from interference by the explorers.

Its shortcomings notwithstanding, monism is solvable if diligent courts flesh out and compel compliance with the obligations that stem from vague declarations of rights.  Formalism is more complicated because it involves a complete, if subtle, break with classic “realist” thinking.  Where the classical legal tradition insists that there is no justice without the actual delivery of the owed thing (“res”), formalism deems justice satisfied so long as a subjective right is declared and its exercise not hindered.  This way of thinking (which permeates Fr. Legge’s article) can be traced back to Opus Nonaginta Dierum, a short treatise where Ockham asserted that friars, by virtue of their vows of poverty, used things without having subjective rights over them.  But of course, if a thing can be had without a subjective right, then a subjective right can also exist without a thing.  Put differently, in the wake of Ockham, ensuring the enforcement of a subjective right is no longer of the essence.[9]  On this view, the proclamation of a right to public housing is already an act of justice, even if not everyone is afforded the means to own a house.   Ultimately, formalism wants to do justice by slogan.

In short, while Fr. Legge is right that modernity has denaturalized subjective rights (including human rights), this has happened not only for the reasons he sets out, but also as a result of viewing subjective rights as the object of justice, which they are not.   They are part of the legal framework, yet not their apex, let alone the object of worship they have become.

—Aníbal Sabater


[1]   Fr. Legge is also the author of a highly commendable presentation on “What Makes A Lawyer Good,” available at: https://www.napalegalinstitute.org/post/what-makes-a-lawyer-good.

[2]   For instance, Edmund Waldstein, O. Cist.extensively considers Fr. Legge’s article in “Rights and the Common Good,” available at https://thejosias.com/2022/03/28/rights-and-the-common-good/.   “Rights and the Common Good” addresses Fr. Legge’s piece in a broader context than is done here.

[3]   That Fr. Legge suggests that Las Casas was a true Thomist, and yet fails to account for Ginés Sepúlveda and Juan de Solórzano Pereyra—two more orthodox Thomists on the question of the Americas—will be charitably ignored here.

[4]   And Fr. Legge is also right that this use of “ius” as subjective right in Aquinas has usually been ignored by traditional Thomistic legal thinkers.

[5]   That “ius” can have several meanings, but as the object of justice it only means the thing or conduct that is due, is made clear at S. Th. Q. 57,  a. 1,  There Aquinas explains how “ius” is sometimes used as “law,” but only improperly as law is not the object of justice.

[6]   On this and several other topics discussed in this article, see generally T. Urdanoz O.P., “Tratado de la Justicia,” in Suma Teológica de Santo Tomas de Aquino VII, 158-230 (2014).

[7]   A subjective right cannot exist without a concomitant obligation, both forming a legal relationship.  Id., 194.

[8]     Recopilación de Leyes de Indias, Libro IV, Título 1, Ley X: “Los descubridores por mar o tierra no se embaracen en guerra ninguna entre unos y otros Indios, ni los ayuden ni revuelvan en qüestiones por ninguna causa ni razón que sea: no les hagan mal, ni daño, ni tomen sus bienes, si no fueren por rescate, o dándoselo ellos por su libre voluntad.”

[9]   For a more detailed analysis of formalism, see Javier Hervada, Lecciones Propedeúticas de Filosofía del Derecho 239-244 (2008).