Born to a noble Sicilian family, it was assumed that his high intellect put Thomas, unlike his military siblings, on a path to becoming a politically prominent and economically powerful abbot. After studying at the University of Naples, where he was introduced to Aristotle, Averroes and Maimonides, Thomas instead chose to enter the Order of Preachers (Dominicans) as a lowly monk. To thwart the fierce opposition of the family, which went so far as to temporarily kidnap him, the Dominicans moved him away, first to Rome then to study at the University of Paris.
Although brilliant, Aquinas was a quiet young man; when he spoke he did so slowly and hesitantly, leading some fellow students to mock him. Dominican scholar Albertus Magnus saw through Aquinas’ demeanor and prophetically remarked: “You call him the dumb ox, but in his teaching he will one day produce such a bellowing that it will be heard throughout the world.”
Magnus borrowed the young scholar from Paris a few years, appointing him master of students at the Dominican house of studies that a century later became part of the University of Cologne. While at Cologne, Thomas wrote a commentary on Lombard’s Sentences. Back in Paris as a professor, he began to write several of his lesser known works covering controversies such as the role of mendicant orders and answering a variety of questions put to him by students. There he also penned his well-known Summa Contra Gentiles (Book on the Truth of the Catholic Faith against the Errors of the Unbelievers).
Aquinas hit his full stride as a scholar during later notable appointments in Italy—among them as papal theologian to Pope Clement IV and later in the Dominican convent of Santa Sabina, where he began to draft his major work, the Summa Theologica.
Even 700 years later, the Summa is still a monumental work, both in size (about 3,500 pages) and scope, yet Thomas started out with the very modest goal “to convey those things that pertain to the Christian religion, in a way that is fitting to the instruction of beginners.”
The Summa is divided into three parts, which some scholars see as a circle that starts with God and ends with God, passing through a broad number of questions of faith in the middle.
Aquinas begins writing about God’s existence. This discussion includes the famous five “proofs” of God. Summarized all too briefly, in these five propositions Aquinas argues for the existence of God as the Being who is the universe’s unmoved mover, its first cause, the one necessary Being, the One who is the ultimate and the intelligent designer of every behavior in nature. Then he writes about divine nature, carefully explaining that characteristics of God that human beings discern are not properties, as we might describe of a rock we can hold in our hands. The traits we say are God’s are only attributes of the unseen divinity, drawn from and within the limits of revelation, experience and reason.
He tackles, in addition, the creation of the world and human nature. In between those two topics, he explores the subject of angels, giving rise to the sardonic question “How many angels can dance on the head of a pin?” posed by dismissive modern critics. Aquinas’ actual question on the subject was: “Can several angels be in the same place?” (Answer: yes and no. See here.)
In the second part, concerning ethics, Aquinas starts from the most general, including a theory of law (effectively a theory of just authority and government). He offers a new take on the just war theory, with very detailed principles and distinctions that help determine whether entering into or pursuing an armed conflict is just. Less commonly mentioned, Aquinas supports human freedom through what I like to call his “just rebellion” theory. He then proceeds to particular human virtues and vices. The Summa’s third part covers Christ as humanity’s path to God, sacraments, ending the work in a section on the end of the world, which he left unfinished.
The Summa is not easy reading—I have only read sections and excerpts. Aquinas’ mind demanded that he capture every possible aspect of an idea before he let it go. Each point in the Summa is presented in an iron-clad format. First he presents a series of objections to an unstated conclusion; then he follows with a counter-statement; next comes an argument in favor of his conclusion; finally, he replies to any objections he thinks he has left unaddressed.
Another reason his work is so difficult is that Aquinas was laboring under a severe handicap. In his day, one had to apply a theory to all possible instances before a proposition was deemed proven. For example, you would have to witness all sunrises to prove the sun rises in the east. It was not until many years later that then-suppressed insights concerning logic, by contemporary Franciscan Friar Roger Bacon, eased the way to what would become the cornerstone of modern science: the incomplete inference. Using the example of the sun, you now can rely on observing the sun rising in the east every day for one week to propose validly that this always happens at sunrise—that is, until some wags such as Copernicus and Galileo upset your applecart by showing that the sun doesn’t rise at all.
The Summa proposed many ideas that today are common, such as that theology can be a rational pursuit of knowledge, or the distinction between something’s existence and essence (uniquely, God’s essence is to exist), or accepted principles of natural law. He also proposed moral teachings that, at a minimum, are at odds with Western conventional wisdom. In the Summa, Aquinas views collecting interest on loans as forbidden, saying it amounts to charging people twice for the same thing. Selling something for more or less than it is worth is unlawful, says the Summa, setting forth a just price theory, also little mentioned by clerics.
Speaking on one of the medieval (and later) moral blemishes of Christians collectively, Aquinas accepts gospel accounts that Jews delivered Jesus Christ to die, but he points out that it was the Gentiles who killed him, foreshadowing how salvation would begin with the Jews and spread to the Gentiles.
Although his work is now regarded as the apex of scholasticism, Aquinas was not acclaimed by the Church until well after his death and he himself did not realize the full value of his contributions.
He was twice accused and condemned of heresy—once while alive and once posthumously. The condemnations—both lifted—were for allegedly promoting Islamic-leaning Averroism and “radical Aristotelianism” involving the idea that everything is only material. Both were currents popular among university students of his day, in part due to their shock value in medieval Christian Europe.
To put Aquinas’ problem in the context of recent times, I commend the reader to a sage remark by Dom Helder Camara, Archbishop of Olinda and Recife in 1960s Brazil. In the middle of the Cold War, Camara argued that Christianity needed a great thinker who would absorb what was worthy in Karl Marx’s thought much the way Aquinas borrowed heavily from Aristotle and metaphorically baptized his ideas.
Aquinas was attacked posthumously, was finally given his due, but later had his name and reputation hijacked by rigorists. He was canonized saint in 1323 by Pope John XXII and in 1567 proclaimed by Pope Pius V a Doctor of the Church on a par with the four great Latin fathers Ambrose, Augustine of Hippo, Jerome and Gregory. However, in an 1879 encyclical, Pope Leo XIII stated that Thomas’ theology was a definitive exposition of Catholic doctrine. Leo directed the clergy to base their theological positions on Thomas and decreed that all Catholic seminaries and universities teach Thomas’ doctrines and regard them as a litmus test for academic theologians.
Thus began a century of Thomism during which all who wished to hold back modern theological inquiry used as their excuse the writings of the saintly scholar who, in life, had been an avid if devout rational explorer of new ideas.
Aside from all that, the Christian behind Aquinas’ writings and controversy emerged toward the end of his own life, long ago.
In 1272, when the Dominicans allowed Thomas to establish a place of study wherever he liked and staff it as he pleased, he chose to leave Paris and move to Naples. There, on December 6, 1273, in the chapel of Saint Nicholas, Thomas had a life-changing spiritual experience. As recounted by witnesses, Thomas lingered after Matins and was seen levitating in prayer, in tears before an icon of the crucified Christ, which spoke to the monk saying, “You have written well of me, Thomas. What reward would you have for your labor?” Thomas replied, “Nothing but you, Lord.”
Thomas never spoke of the episode or wrote it down, but he stopped dictating to his assistant Reginald of Piperno. When Reginald begged him to get back to work, Thomas replied: “Reginald, I cannot, because all that I have written seems like straw to me.”
After that, Thomas wrote devotional works. My favorite is the Eucharistic hymn Godhead Here in Hiding (Adoro te devoto), translated into English from Latin by the 19th-century poet Gerard Manley Hopkins, S.J. The most common musical setting is available sung by nuns here, but my favorite scoring, less popular, is the arrangement by Phillip Pennington Harris, available unsung, here.
To end this brief encounter with Aquinas, consider this hymn’s opening words, which follow:
Godhead here in hiding,
whom I do adore,
Masked by these bare shadows,
shape and nothing more.
See, Lord, at thy service
low lies here a heart lost,
all lost in wonder
at the God thou art.