Saint Thomas Aquinas was a Dominican friar and preeminent philosopher and theologian whose systematic writings profoundly shaped Western thought and remain foundational to doctrine.
Saint Thomas Aquinas, often called the "Angelic Doctor" and "Common Doctor," was an Italian Dominican friar, priest, and immensely influential philosopher and theologian of the 13th century. His monumental work, the Summa Theologica, systematically synthesized classical philosophy, particularly that of Aristotle, with revelation, providing a comprehensive framework for understanding God, creation, and humanity's purpose. His rigorous intellectual method and profound insights laid much of the philosophical and theological groundwork for teachings, making him a central figure in scholasticism and a lasting guide for theological inquiry and spiritual formation.
Born in 1225 to a noble family in Roccasecca, Italy, Thomas Aquinas entered a world steeped in both feudal power and burgeoning intellectual ferment. His father, Landulf, Count of Aquino, and his mother, Theodora, Countess of Teano, intended for him to follow a traditional path, likely as an abbot of Monte Cassino, where he began his education at the age of five. This early exposure to monastic life and rigorous study laid a foundational stone for his disciplined intellect. However, Thomas's heart yearned for a different calling. While studying at the University of Naples, he encountered the newly founded Dominican Order, captivated by their commitment to poverty, preaching, and scholarship. His decision to join the Dominicans, a mendicant order, was met with fierce opposition from his family, who saw it as a betrayal of their aristocratic lineage and a squandering of his potential for ecclesiastical power. They even resorted to kidnapping and imprisoning him in their castle for over a year, attempting to dissuade him, but Thomas remained steadfast in his vocation, famously resisting even the temptation of a prostitute sent to undermine his resolve. This early trial forged a spirit of unwavering commitment to his chosen path, one dedicated entirely to God and the pursuit of truth.
Upon his release, Thomas officially entered the Dominican Order in 1244 and was sent to study in Paris and then Cologne under the tutelage of the renowned Dominican scholar, Saint Albert the Great. Albert quickly recognized Thomas's extraordinary intellectual gifts, defending him against fellow students who, observing his quiet and thoughtful demeanor, mockingly called him the "Dumb Ox." Albert famously retorted, "We call him the dumb ox, but in his teaching he will one day produce such a bellowing that it will be heard throughout the whole world." This period of intense study immersed Thomas in the philosophical works of Aristotle, which had recently been reintroduced to Western Europe through Arabic translations. While many Christian scholars viewed Aristotle with suspicion, seeing his philosophy as potentially undermining faith, Thomas, guided by Albert, saw an opportunity to integrate reason and revelation, laying the groundwork for his groundbreaking intellectual synthesis.
Thomas returned to Paris in 1252 to teach and eventually became a master of theology. It was during this time that he began to develop his unique scholastic method, characterized by rigorous logical argumentation, the careful examination of opposing viewpoints, and the ultimate reconciliation of seemingly disparate truths. His most monumental work, the *Summa Theologica*, begun around 1265, stands as a testament to this method. Though unfinished at his death, it is a comprehensive systematic theology that addresses nearly every theological question of his time, from the existence of God to the nature of sacraments and the moral life. He meticulously structured his arguments, posing questions, presenting objections, offering his own solutions, and refuting the objections, thereby creating a profound and enduring framework for theological inquiry.
Beyond the *Summa Theologica*, Thomas produced an astonishing volume of work, including the *Summa Contra Gentiles*, a work aimed at defending Christian truth against non-Christian philosophical and theological objections, particularly from Muslim and Jewish thinkers. He also wrote numerous commentaries on Scripture, Aristotle, and other philosophical works, as well as disputations and Quodlibetal Questions. His writings consistently demonstrated his profound belief that faith and reason are not in opposition but are complementary paths to truth, both ultimately originating from God. He argued that reason could lead to certain truths about God and the natural world, while revelation provided access to truths beyond the grasp of pure reason, such as the Trinity or the Incarnation. This harmonious vision of faith and reason became a cornerstone of Catholic intellectual tradition.
Thomas's intellectual prowess and prolific output profoundly shaped the course of Western thought. His systematic approach and the clarity of his arguments not only revolutionized theology but also influenced philosophy, ethics, and law. His work provided a robust intellectual defense for Christian doctrine, making it accessible and intelligible to generations of scholars. The school of thought derived from his work, known as Thomism, became the dominant philosophical and theological framework within the Catholic Church, particularly after the Council of Trent and its subsequent reaffirmation by various popes, notably Pope Leo XIII in his encyclical *Aeterni Patris* (1879), which declared Thomism the perennial philosophy of the Church. His synthesis continues to provide a vital framework for understanding the relationship between God, humanity, and the created order.
In his later years, Thomas experienced profound mystical encounters that transcended his intellectual pursuits. On December 6, 1273, while celebrating Mass, he had such an intense spiritual experience that he ceased all writing. When urged by his secretary, Reginald of Piperno, to continue the *Summa Theologica*, Thomas famously replied, "All that I have written seems like straw to me compared to what has been revealed to me." He never wrote again, feeling that all his previous intellectual achievements paled in comparison to the divine mysteries he had glimpsed. He died a few months later, on March 7, 1274, at Fossanova Abbey, while en route to the Second Council of Lyon. Canonized by Pope John XXII in 1323 and declared a Doctor of the Church by Pope Pius V in 1567, Saint Thomas Aquinas remains one of the most influential figures in Christian history, a towering intellect whose life and work continue to illuminate the profound harmony between faith and reason, guiding countless souls in their pursuit of divine truth.
It was the feast of Saint Nicholas, December 6th, in the year of our Lord 1273. Saint Thomas Aquinas, the great 'Angelic Doctor,' was celebrating Mass in the Dominican convent church of Naples. For years, he had poured his immense intellect and profound piety into the *Summa Theologica*, a monumental work designed to synthesize all Christian doctrine, a true testament to the harmony of faith and reason. But on this particular morning, something extraordinary occurred.
As Thomas elevated the Sacred Host, a transformation came over him. His face, usually serene and contemplative, seemed to radiate an inner light. When Mass concluded, he returned to his cell, but he did not pick up his pen. He did not dictate to his faithful secretary, Reginald of Piperno, as was his custom. He sat in silence, lost in a profound contemplation.
Reginald, ever diligent, grew concerned. The *Summa Theologica* was nearing completion, and there was still so much to write, so many questions to answer. He gently urged Thomas to continue his work, reminding him of the importance of this theological masterpiece for the Church. But Thomas, his eyes still distant, filled with an otherworldly light, simply replied, with a voice full of awe and humility, 'Reginald, I can write no more.'
Reginald, perplexed, pressed him further. 'Master, what is it? Why have you stopped?'
Thomas, after a moment, spoke words that would echo through the centuries, revealing the depth of his spiritual encounter: 'All that I have written seems like straw to me compared to what has been revealed to me.' From that day forward, the greatest theologian of his age, the author of countless volumes, never wrote another word. His intellectual journey had culminated in a direct encounter with divine truth that transcended all earthly wisdom, a powerful testament to his ultimate goal: not merely to know about God, but to know God Himself.
c. 1265-1274
Summa Theologica, Part I, Question 2, Article 3: Whether God exists?
Objection 1. It seems that God does not exist; because if one of two contraries be infinite, the other would be altogether destroyed. But the name God means that He is infinite goodness. If, therefore, God existed, there would be no evil discoverable; but there is evil in the world. Therefore God does not exist.
Objection 2. Further, it is superfluous to suppose that what can be accounted for by a few principles has been produced by many. But it seems that everything we see in the world can be accounted for by other principles, supposing God did not exist. For all natural things can be reduced to one principle, which is nature; and all voluntary things can be reduced to one principle, which is human reason, or will. Therefore there is no need to suppose God's existence.
On the contrary, Damascene says (De Fide Orthodoxa i, 3): "The existence of God is self-evident."
I answer that, The existence of God can be proved in five ways.
The first and more manifest way is taken from motion. It is certain, and evident to our senses, that in the world some things are in motion. Now whatever is in motion is put in motion by another, for nothing can be in motion except it is in potentiality to that towards which it is in motion; whereas a thing moves inasmuch as it is in act. For motion is nothing else than the reduction of something from potentiality to actuality. But nothing can be reduced from potentiality to actuality, except by something in a state of actuality. Thus that which is actually hot, as fire, makes wood, which is potentially hot, to be actually hot, and thereby moves and changes it. Now it is not possible that the same thing should be at once in actuality and potentiality in the same respect, but only in different respects. For what is actually hot cannot simultaneously be potentially hot; but it is simultaneously potentially cold. It is therefore impossible that in the same respect and in the same way a thing should be both mover and moved, i.e. that it should move itself. Therefore, whatever is in motion must be put in motion by another. If that by which it is put in motion be itself put in motion, then this also must needs be put in motion by another, and that by another again. But this cannot go on to infinity, because then there would be no first mover, and, consequently, no other mover; seeing that subsequent movers move only inasmuch as they are put in motion by the first mover; as the staff moves only because it is moved by the hand. Therefore it is necessary to arrive at a first mover, put in motion by no other; and this everyone understands to be God.
The second way is from the nature of the efficient cause. In the world of sense we find there is an order of efficient causes. There is no case known (neither is it, indeed, possible) in which a thing is found to be the efficient cause of itself; for so it would be prior to itself, which is impossible. Now in efficient causes it is not possible to go on to infinity, because in all efficient causes following in order, the first is the cause of the intermediate cause, and the intermediate is the cause of the ultimate cause, whether the intermediate cause be several, or only one. Now to take away the cause is to take away the effect. Therefore, if in efficient causes it is possible to go on to infinity, there will be no first efficient cause, neither will there be any ultimate effect, nor any intermediate efficient causes; all of which is plainly false. Therefore it is necessary to suppose some first efficient cause, to which everyone gives the name of God.
The third way is taken from possibility and necessity, and runs thus. We find in nature things that are possible to be and not to be, since they are found to be generated, and to corrupt, and consequently, they are possible to be and not to be. But it is impossible for these always to exist, for that which is possible not to be at some time is not. Therefore, if everything is possible not to be, then at one time there could have been nothing in existence. Now if this were true, even now there would be nothing in existence, because that which does not exist only begins to exist by something already existing. Therefore, if at one time nothing was in existence, it would have been impossible for anything to have begun to exist; and thus even now nothing would be in existence—which is absurd. Therefore, not all beings are merely possible, but there must exist something the existence of which is necessary. But every necessary thing either has its necessity caused by another, or not. Now it is impossible to go on to infinity in necessary things which have their necessity caused by another, as has been already proved in regard to efficient causes. Therefore we cannot but postulate the existence of some being having of itself its own necessity, and not receiving it from another, but rather causing in others their necessity. This all men speak of as God.
The fourth way is taken from the gradation to be found in things. Among beings there are some more and some less good, true, noble, and the like. But "more" and "less" are predicated of different things, according as they resemble in their different ways something which is the maximum, as a thing is said to be hotter according as it more nearly resembles that which is hottest; so that there is something which is truest, something best, something noblest, and, consequently, something which is most being. For those things that are greatest in truth are greatest in being, as it is written in Metaph. ii. Now the maximum in any genus is the cause of all in that genus; as fire, which is the maximum of heat, is the cause of all hot things. Therefore there must also be something which is to all beings the cause of their being, goodness, and every other perfection; and this we call God.
The fifth way is taken from the governance of the world. We see that things which lack intelligence, such as natural bodies, act for an end, and this is apparent from their acting always, or nearly always, in the same way, so as to obtain the best result. Hence it is plain that not fortuitously, but designedly, do they achieve their end. Now whatever lacks intelligence cannot move towards an end, unless it be directed by some being endowed with intelligence and knowledge; as the arrow is directed by the archer. Therefore some intelligent being exists by whom all natural things are directed to their end; and this being we call God.
Reply to Objection 1. As Augustine says (Enchiridion xi): "Since God is the highest good, He would not allow any evil to exist in His works, unless His omnipotence and goodness were such as to bring good even out of evil." This is part of the infinite goodness of God, that He should allow evil to exist, and out of it produce good.
Reply to Objection 2. Because nature works for a determinate end under the direction of a higher agent; and whatever is done by art is done under the direction of reason. Hence the whole of nature is directed to its end by some higher reason, and this is God.
August 4, 1879
And now, Venerable Brethren, as We call to mind the solicitude of the Apostolic See, extending over so many centuries, for the protection of the doctrine of Thomas Aquinas, and the orders so frequently and earnestly repeated by Our Predecessors, We clearly see what ought to be done in this matter of paramount importance, according to the example of the greatest pontiffs, and as the requirements of the present day demand. We have already declared that the capital point was to restore the teaching of Thomas Aquinas to its former honor, and to repair the losses for which the neglect of later ages has been to blame. We now desire to explain more fully the manner in which this may best be done.
We exhort you all, Venerable Brethren, with the greatest earnestness to restore the golden wisdom of St. Thomas, and to spread it far and wide for the defense and beauty of the Catholic faith, for the good of society, and for the advantage of all the sciences. The wisdom of St. Thomas, We say; for if there is any defect in the scholastic writers, or if they anywhere too carelessly treated anything, or if they took up any doctrines that are untenable, it does not enter Our mind to propose that for imitation in Our age.
What We commend to you is the wisdom of St. Thomas Aquinas, and We wish that it be diligently and religiously followed by all. For in his writings, the principles and laws of the true philosophy are laid down which, as We have shown, are of the greatest importance for the safeguarding of the faith and for the good of society. It is the wisdom of St. Thomas, We repeat, which is to be preferred above all others, and which is to be most carefully followed, in all those things which are of the greatest moment for the preservation of the Catholic faith.
Let, then, sacred pastors and all who have the charge of souls, urge and persuade the faithful to the study of the Angelic Doctor, and let them explain to them the utility and excellence of his doctrine. Let them, moreover, see to it that the youth in the seminaries and universities are carefully instructed in this philosophy, and let them themselves, as far as they are able, embrace it and teach it. Let them, in fine, take care that this philosophy be not only taught in the schools, but that it also be cultivated and spread abroad in the homes of the faithful, so that it may bear fruit in the lives of men.
And that you, Venerable Brethren, may be able to carry out Our wishes with greater ease and success, We declare that it is Our will that in all the seminaries and universities, and in all the colleges and institutes which are subject to Our jurisdiction, the philosophy of St. Thomas Aquinas be taught. And We further declare that We wish this teaching to be so understood and explained as to be in accordance with the true sense of the Angelic Doctor, and that it be not corrupted by any false interpretations.
We therefore exhort all of you, Venerable Brethren, to devote yourselves with all zeal and diligence to the execution of this Our will, and to use all your efforts to promote the study of the philosophy of St. Thomas Aquinas, for the glory of God, for the good of the Church, and for the salvation of souls.
Let, therefore, the teachers chosen to instruct the young in sacred theology use the Summa Theologica of St. Thomas Aquinas as the text-book of their lessons, and let them explain it with the greatest care and diligence, so that the students may be thoroughly imbued with the principles and method of the Angelic Doctor. And let them, moreover, take care that the students be not only instructed in the doctrine of St. Thomas, but that they also be trained in the method of his reasoning, so that they may be able to defend the truth and refute error with solid arguments.
And let them, finally, take care that the students be not only instructed in the doctrine and method of St. Thomas, but that they also be imbued with his spirit of piety and devotion, so that they may be able to unite knowledge with holiness, and to serve God with a pure heart and an enlightened mind.
These things, Venerable Brethren, We have thought it good to write to you, in order that you may know Our mind and will concerning the study of the philosophy of St. Thomas Aquinas. And We doubt not that, with the help of God, and with your diligent cooperation, Our wishes will be carried into effect, and that great fruit will result therefrom for the Church and for souls.
Catholic universities and schools often hold special Masses, lectures, or academic events on his feast day, honoring him as their patron and a model of intellectual pursuit in service of faith.
Saint Thomas Aquinas is the patron saint of students, universities, and Catholic schools, revered for his profound intellectual contributions and his synthesis of faith and reason, which remains central to Catholic education.
Students and academics frequently invoke Saint Thomas Aquinas through prayer for intercession, seeking his guidance and assistance in their studies, research, and examinations.
As the patron saint of students and scholars, he is considered a powerful intercessor for intellectual endeavors, known for his clarity of thought and dedication to truth.
Theological seminaries and philosophical institutes within the Catholic Church worldwide often dedicate studies or discussions to his works on his feast day, emphasizing his enduring relevance.
He is a Doctor of the Church, whose systematic theology and philosophy, particularly the Summa Theologica, are foundational to Catholic doctrine and intellectual tradition.