25 Thomas Aquinas Quotes on Faith, Reason, and the Nature of God
Thomas Aquinas (1225-1274) was an Italian Dominican friar, philosopher, and theologian whose synthesis of Aristotelian philosophy with Christian theology became the intellectual foundation of the Catholic Church. Known as the "Angelic Doctor," he was so large and quiet as a student that his classmates nicknamed him "the Dumb Ox" -- until his teacher, Albertus Magnus, reportedly declared, "We call this young man a dumb ox, but his bellowing in doctrine will one day resound throughout the world." His Summa Theologica, though left unfinished, remains one of the most systematic works of philosophical theology ever written.
When the young Thomas Aquinas announced his intention to join the Dominican order -- a mendicant order of wandering preachers who begged for their living -- his aristocratic family was so horrified that his brothers kidnapped him and imprisoned him in the family castle for over a year. According to legend, they even sent a prostitute to his room to tempt him from his vocation; Thomas reportedly chased her away with a burning log from the fireplace. He eventually escaped (or was released) and joined the Dominicans, going on to produce a body of work of staggering scope and precision. Working with the recently rediscovered texts of Aristotle, which many churchmen considered dangerously pagan, Aquinas demonstrated that faith and reason are complementary paths to truth. As he wrote: "To one who has faith, no explanation is necessary. To one without faith, no explanation is possible." That elegant formulation of the relationship between belief and understanding captures the essence of his life's project -- building a bridge between the truths of revelation and the truths of reason.
Who Was Thomas Aquinas?
| Item | Details |
|---|---|
| Born | 1225, Roccasecca, Kingdom of Sicily (present-day Italy) |
| Died | 7 March 1274 (aged 49), Fossanova Abbey, Italy |
| Nationality | Italian |
| Occupation | Philosopher, Theologian, Friar |
| Known For | Summa Theologica, Five Ways (proofs of God), Scholasticism |
Key Achievements and Episodes
The Family That Tried to Stop Him
When the young Thomas announced his intention to join the Dominican order of mendicant friars, his aristocratic family was horrified — they had expected him to become a wealthy Benedictine abbot. His brothers kidnapped him and imprisoned him in the family castle for nearly two years, even sending a prostitute to his room to tempt him from his vocation. Thomas reportedly chased her away with a burning log and remained steadfast in his calling.
The Dumb Ox
As a student in Cologne under Albertus Magnus, Thomas was so quiet and large that his classmates nicknamed him "the Dumb Ox." Albertus Magnus reportedly told them, "You call him a dumb ox, but I tell you that this dumb ox will bellow so loud that his bellowing will fill the world." This prediction proved accurate — Thomas became the most influential theologian in Catholic history, producing an estimated eight million words during his career.
The Mystical Experience That Ended His Writing
On December 6, 1273, while celebrating Mass, Thomas had a mystical experience after which he stopped writing entirely. When his secretary urged him to continue the Summa Theologica, Thomas replied, "Everything I have written seems like straw compared to what has been revealed to me." He died three months later at age 49, leaving his greatest work unfinished.
Who Was Thomas Aquinas?
Born into an aristocratic family in Roccasecca, Italy, Thomas Aquinas defied his family’s wishes for him to become a Benedictine abbot and instead joined the Dominican Order -- a mendicant community devoted to preaching and scholarship. His family was so opposed to the decision that they held him captive for nearly a year, yet Thomas never wavered. He eventually studied under Albertus Magnus in Cologne and Paris, where his extraordinary intellect quickly became apparent.
Aquinas’s greatest achievement was demonstrating that the philosophy of Aristotle could be harmonized with Christian theology. At a time when many churchmen viewed Aristotle’s rediscovered works with suspicion, Thomas embraced them, arguing that truths discovered by reason and truths revealed by faith ultimately spring from the same divine source. His masterwork, the Summa Theologica, remains one of the most systematic and ambitious works of philosophy ever written, addressing questions from the existence of God to the nature of human happiness.
Beyond theology, Aquinas made lasting contributions to ethics, natural law theory, and political philosophy. His concept of natural law -- the idea that moral principles are grounded in human nature and accessible to reason -- influenced legal traditions across the world. He also developed the doctrine of double effect, which remains central to modern ethical debates in medicine, warfare, and public policy.
Thomas Aquinas died at the age of 49, reportedly saying that all he had written seemed “like straw” compared to what had been revealed to him in a mystical experience near the end of his life. He was canonized in 1323 and declared a Doctor of the Church. His thought, known as Thomism, continues to be the official philosophical framework of the Catholic Church and a cornerstone of Western intellectual history.
Thomas Aquinas Quotes on Faith and Reason
Thomas Aquinas quotes on faith and reason address the central project of his intellectual life: demonstrating the harmony between Christian revelation and Aristotelian philosophy. Aquinas argued that faith and reason are not contradictory but complementary — two distinct paths to truth that, properly understood, can never conflict because both ultimately derive from God. This synthesis was revolutionary in the thirteenth century, when the rediscovery of Aristotle's complete works through Arabic translations threatened to undermine Christian theology. When the young Thomas announced his intention to join the Dominican order — mendicant friars who begged for their living — his aristocratic family was so horrified that his brothers kidnapped him and locked him in a tower for nearly two years, even sending a beautiful woman to his room to tempt him away from his vocation. Thomas reportedly drove her away with a burning brand from the fireplace and spent his captivity studying Aristotle and the Bible. His masterwork, the Summa Theologica (1265-1274), systematically addresses over 500 questions through the method of objections, replies, and counter-replies, creating the most comprehensive work of philosophical theology in the Western tradition.
“To one who has faith, no explanation is necessary. To one without faith, no explanation is possible.”
Attributed - On the divide between belief and unbelief
“Faith has to do with things that are not seen, and hope with things that are not at hand.”
Summa Theologica - On the theological virtues
“Reason in man is rather like God in the world.”
Opuscule II - On the divine quality of human intellect
“The truth of our faith becomes a matter of ridicule among the infidels if any Catholic, not gifted with the necessary scientific learning, presents as dogma what scientific scrutiny shows to be false.”
Summa Theologica - On the responsibility to reconcile faith and evidence
“Beware of the person of one book.”
Attributed - On the danger of narrow learning
“The things that we love tell us what we are.”
Attributed - On the revelatory nature of love
“Wonder is the desire for knowledge.”
Summa Theologica, I-II, q. 32 - On the beginning of all inquiry
Thomas Aquinas Quotes on the Nature of God
Thomas Aquinas quotes on the nature of God reflect his ambitious attempt to understand the divine through the combined resources of reason and revelation. His famous Five Ways — five philosophical arguments for God's existence presented in the Summa Theologica — proceed from observable features of the natural world (motion, causation, contingency, degrees of perfection, and purposeful order) to the conclusion that a First Mover, First Cause, Necessary Being, Supreme Perfection, and Intelligent Designer must exist. These arguments, rooted in Aristotelian metaphysics, have been debated continuously for over seven centuries and remain central to the philosophy of religion. Aquinas was so large and quiet as a student at the University of Cologne that his classmates nicknamed him "the Dumb Ox" — until his teacher, Albertus Magnus, reportedly declared, "We call this young man a dumb ox, but his bellowing in doctrine will one day resound throughout the world." His philosophical theology, adopted by the Catholic Church as its official philosophy in 1879, distinguishes between truths knowable by reason alone (God's existence, the natural law) and truths accessible only through revelation (the Trinity, the Incarnation), maintaining that both sets of truths form a harmonious whole.
“God is not a being among beings. He is the act of being itself.”
Summa Theologica, I, q. 3 - On divine simplicity
“The soul is known by its acts.”
Summa Theologica - On understanding the nature of the soul through action
“Because philosophy arises from awe, a philosopher is bound in his way to be a lover of myths and poetic fables. Poets and philosophers are alike in being big with wonder.”
Commentary on Aristotle’s Metaphysics - On philosophy and wonder
“To know that God exists in a general and confused way is implanted in us by nature.”
Summa Theologica, I, q. 2, a. 1 - On natural knowledge of God
“Not everything that is more difficult is more meritorious.”
Summa Theologica - On the true measure of virtue
“Whatever is received is received according to the nature of the recipient.”
Summa Theologica, I, q. 75 - On how knowledge is shaped by the knower
Thomas Aquinas Quotes on Virtue and Morality
Thomas Aquinas quotes on virtue and morality present his synthesis of Aristotelian ethics with Christian theology, creating a moral framework that continues to guide Catholic social teaching and natural law theory. Aquinas adopted Aristotle's four cardinal virtues — prudence, justice, fortitude, and temperance — and supplemented them with the three theological virtues of faith, hope, and charity, arguing that while natural virtues can be developed through human effort, the theological virtues require divine grace. His ethical theory, developed in the Secunda Pars (Second Part) of the Summa Theologica, is fundamentally teleological: human actions are morally evaluated according to whether they direct us toward our ultimate end (beatitudo, or blessed union with God) or lead us away from it. His natural law theory — the idea that moral principles are inscribed in human nature and accessible to reason — has profoundly influenced Western legal theory, the Catholic Church's positions on social justice and human rights, and the development of international law. Aquinas's concept of the "just war" — conditions under which armed conflict can be morally justified — continues to shape debates about military intervention, humanitarian warfare, and the ethics of armed conflict.
“Good can exist without evil, whereas evil cannot exist without good.”
Summa Theologica, I, q. 48 - On the parasitic nature of evil
“Justice is a certain rectitude of mind whereby a man does what he ought to do in the circumstances confronting him.”
Summa Theologica, II-II, q. 58 - On the definition of justice
“Sorrow can be alleviated by good sleep, a bath, and a glass of wine.”
Commentary on Aristotle’s Ethics - On practical remedies for grief
“There is nothing on this earth more to be prized than true friendship.”
Attributed - On the supreme value of genuine human bonds
“If the highest aim of a captain were to preserve his ship, he would keep it in port forever.”
Attributed - On the necessity of risk in pursuit of purpose
”An unjust law is a human law that is not rooted in eternal law and natural law.”
Summa Theologica, I-II, q. 95 - On the moral limits of legislation
Thomas Aquinas Quotes on Knowledge and Truth
Thomas Aquinas quotes on knowledge and truth express his epistemological optimism — his conviction that human reason, though limited, is genuinely capable of grasping important truths about God, nature, and morality. His definition of truth as the correspondence between the intellect and reality (adaequatio rei et intellectus) became the standard formulation of the correspondence theory of truth in Western philosophy. Aquinas's intellectual productivity was legendary: in addition to the Summa Theologica (which runs to several thousand pages in modern editions) and the Summa contra Gentiles, he wrote extensive commentaries on Aristotle, biblical commentaries, and numerous shorter works. He reportedly dictated to multiple secretaries simultaneously, composing different works at the same time. On December 6, 1273, while celebrating Mass, Aquinas had a mystical experience after which he stopped writing entirely, declaring: "All that I have written seems to me like straw compared to what has now been revealed to me." He died three months later on March 7, 1274, at the age of forty-nine, leaving the Summa Theologica unfinished — one of the most poignant silences in the history of philosophy.
“The study of truth requires a considerable effort.”
Summa Contra Gentiles, I, ch. 4 - On the difficulty of philosophical inquiry
“We can’t have full knowledge all at once. We must start by believing; then afterwards we may be led on to master the evidence for ourselves.”
Commentary on the Apostles’ Creed - On the gradual nature of understanding
“Better to illuminate than merely to shine.”
Summa Theologica, II-II, q. 188 - On the duty to share knowledge
“The human mind cannot grasp the essence of even a fly.”
Attributed - On intellectual humility before the complexity of creation
“It is requisite for the good of the human community that there should be persons who devote themselves to the life of contemplation.”
Summa Theologica, II-II, q. 182 - On the social value of the contemplative life
“To teach in order to lead others to faith is the task of every preacher and of each believer.”
Summa Theologica - On the universal call to share truth
Frequently Asked Questions About Thomas Aquinas
What are Thomas Aquinas' five proofs for God's existence?
In his Summa Theologiae (1265-1274), Thomas Aquinas presented five arguments (the Five Ways or Quinque Viae) for God's existence. The First Way argues from motion: everything in motion must have been moved by something else, leading back to an Unmoved Mover. The Second Way argues from efficient causation: every effect has a cause, leading to a First Cause. The Third Way argues from contingency: everything that exists could not exist, so there must be a Necessary Being. The Fourth Way argues from degrees of perfection: varying degrees of goodness, truth, and nobility point to a maximum that is the cause of all perfection. The Fifth Way argues from design: natural things act purposefully, implying an intelligent designer. These arguments have been debated for over 750 years and remain central to philosophy of religion.
How did Aquinas reconcile faith and reason?
Thomas Aquinas' greatest achievement was his synthesis of Christian theology with Aristotelian philosophy, arguing that faith and reason are complementary rather than contradictory. Aquinas maintained that some truths about God can be known through reason alone (such as God's existence and certain divine attributes), while other truths require divine revelation (such as the Trinity and the Incarnation). Reason and faith can never genuinely conflict because both come from God, the source of all truth. When they appear to conflict, either the reasoning is faulty or the scripture is being misinterpreted. This balanced approach, formalized in his massive Summa Theologiae, became the official philosophical position of the Catholic Church and profoundly shaped Western intellectual history.
What is natural law theory according to Aquinas?
Thomas Aquinas' natural law theory holds that certain moral principles are embedded in the nature of things by God and can be discovered through human reason. Aquinas identified four types of law: eternal law (God's plan for all creation), natural law (the rational creature's participation in eternal law), human law (specific legislation derived from natural law), and divine law (God's specific commands in Scripture). The fundamental principle of natural law is "good is to be done and pursued, and evil is to be avoided." From this, Aquinas derived basic moral precepts: preserve life, educate children, live in society, and seek truth about God. Natural law theory has profoundly influenced Catholic moral teaching, Western legal theory, and international human rights law.
Related Quote Collections
- Aristotle Quotes — The philosopher Aquinas called 'The Philosopher'
- Plato Quotes — Platonic influence on Christian thought
- Pascal Quotes — Faith, reason, and the limits of proof
- Faith Quotes — Belief supported by reason
- Wisdom Quotes — The harmony of knowledge and faith