St. Paul advises us to think about whatever is dikaia, which is justa in Latin and just in English. So just what is dikaia, justa, or just? Let us begin by examining definitions of justice from great thinkers, including a great Greek philosopher and two great Latin-writing theologians, all of whom are addressed in the writings of St. Thomas Aquinas (ST, II-II, q. 58, “Of Justice”):

  • Per St. Isidore of Seville: “Rendering to each one his right is so to be just because he respects the rights of others.”
  • Per Aristotle, justice is “a habit which makes a man capable of doing what is just, and of being just in action and in intention,” and “justice is a habit whereby a man renders to each one his due by a constant and perpetual will.”
  • Per St. Augustine: “Justice is love serving God alone.”

Next, let us see how St. Thomas clarified the meanings of each of these definitions, beginning with St. Isidore’s reference to “rights.” Indeed, Thomas’s first question in his incredibly thorough treatment of justice—a full 66 questions and an astounding 302 articles—begins not with question 58, “Of Justice,” but with question 57, “Of Right.” He tells us that the word justice derives from the Latin word jus (or ius), which means “right.” A fundamental act of rendering each person his “due,” in Aristotle’s language, is to respect his fundamental rights. And what are fundamental rights? Borrowing from the Greco-Roman and Judeo-Christian heritage of “natural law and “natural rights,” the American Founding Fathers wrote in our Declaration of Independence that all men are created equal and are “endowed by their Creator with certain inalienable Rights, that among these are Life, Liberty, and the Pursuit of Happiness.” These are among the most fundamental rights we must render to one another, in man’s just laws, mirroring the justice of God’s divine law.

One very pithy definition of justice, then, is “to render to each person his rightful due.” Of course, if St. Thomas could devote 302 articles in more than 250 pages to justice in the Summa, we can rightly surmise that there remains a lot more to be said about justice. Let’s begin with a look at two more dimensions of the definition of justice.

Aristotle’s definition mentions justice as a “habit” through which we render each person his or her rightful due, a habit that makes us “capable of doing what is just, and of being just in action and in intention.” In addressing this statement in his commentary on Aristotle’s Nicomachean Ethics, Thomas elaborates that justice is a habit that brings about three effects within us: “The first is an inclination to a work of justice in accord with which a man is said to be disposed to just works. The second is a just action. The third is that a man wants to perform just actions.”

Now, as for the word habit, note well that for Aristotle and Thomas (and, in fact, for all of us), habits are tendencies we build in ourselves to think, desire, and act in certain ways, good habits being virtues and bad habits being vices. Virtuous acts flow from virtues as sins flow from vices. Justice, then, as a good habit, is indeed a virtue we are called to build in ourselves. As the virtue of justice grows in our souls, we develop a habitual tendency or inclination toward justice rather than injustice, we perform just acts, and indeed, we desire to do so. If we are to heed St. Paul’s advice to “think about” justice, we will think about ways we can build this righteous and beautiful habit in our souls.

Of course, as much as St. Paul admired the natural wisdom of ancient philosophers such as Aristotle, he knew well of the one God of Abraham, Isaac, and Jacob and of His holy Son, who had come to earth, suffered, died, and rose again for our salvation. Paul’s Christian understanding of justice transcends the merely natural plane and reaches all the way up to God. This we see in St. Augustine’s definition of justice as “love serving God alone.” Indeed, the virtue of justice is served in every one of God’s Ten Commandments. When we worship only the true God, when we refrain from using His name in vain, and when we honor Him on the Lord’s Day, we render what is due to our Maker. When we honor our parents and abstain from killing, adultery, stealing, false witness, and coveting our neighbor’s wife and goods, we render due rights to others. Lest Augustine’s reference to serving God “alone” be misunderstood to exclude what is due to others here on earth, Thomas clarifies as follows: “Just as love of God includes love of neighbor . . . so too the service of God includes rendering to each one his due.” As God freely shares His love with us, He bids us share our love with those around us. If you’ll forgive my attempt at a rhyme to remember:“Rendering our neighbors their rightful due is precisely the right and just thing to do.”


This article on Justice According to St. Paul is adapted from the book St. Paul’s Eight Steps to Happiness by Kevin Vost which is available from Sophia Institute Press.

Art for this post on a reflection from “St. Paul’s Eight Steps to Happiness” by Kevin Vost: Cover image used with permission; Featured image by Photo by Tingey Injury Law Firm on Unsplash

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