This page aims to make learning about the philosophy of St. Thomas Aquinas as easy as possible by bringing together the best articles, podcasts, and videos from across the internet onto one page. To get started, simply choose one of the resources listed below, or browse a selection of key quotes by Aquinas at the bottom of the page.
This section features articles from the Stanford Encyclopedia of Philosophy and the Internet Encyclopedia of Philosophy. The SEP is probably the most comprehensive online philosophy resource. It features in-depth articles on a huge number of philosophical topics, however, it is aimed at an academic audience and may be too detailed and technical for beginners. The IEP is generally more beginner-friendly but is also considered to be less reliable. Wikipedia is also an option, but it is much less reliable than either of these.
Stanford Encyclopedia of Philosophy
Internet Encyclopedia of Philosophy
- Thomas Aquinas
- Thomas Aquinas: Moral Philosophy
- Aquinas: Philosophical Theology
- Thomas Aquinas: Political Philosophy
- Aquinas: Metaphysics
This section features short articles written by professional philosophers and aimed at a general audience. These articles are ideal for anyone looking for a shorter or more beginner-friendly introduction to Aquinas than the encyclopedia articles listed above.
- Thomas Aquinas, part 1: rediscovering a father of modernity
- Thomas Aquinas, part 2: the mind as soul
- Thomas Aquinas, part 3: scripture, reason and the being of God
- Thomas Aquinas, part 4: how did the world begin?
- Thomas Aquinas, part 5: what does it mean to be human?
- Thomas Aquinas, part 6: natural law
- Thomas Aquinas, part 7: the question of evil
- Thomas Aquinas, part 8: Thomas for today
This section features episodes from leading philosophy podcasts. These are also aimed at a general audience and are a good option for beginners who prefer audio content.
The History of Philosophy Without Any Gaps
- The Ox Heard Round the World: Thomas Aquinas
- Everybody Needs Some Body: Aquinas on Soul and Knowledge
- What Comes Naturally: Ethics in Albert and Aquinas
- What Pleases the Prince: The Rule of Law
- Onward, Christian Soldiers: Just War Theory
- Scott MacDonald on Aquinas
In Our Time
New Books in Philosophy
Short Videos (<30 mins)
This section features short videos aimed at beginners.
BBC Radio 4
Lectures/Longer Videos (>30 mins)
This section features longer videos and lectures.
- Medieval Philosophy: Thomas Aquinas (Playlist)
- Aquinas and Happiness: A Lecture by Dr. Jennifer Frey
- Aquinas and the Life of the Mind, Stephen Brock
See this collection of course syllabi on Aquinas.
See this list of the best books on Aquinas.
This section features a selection of key quotes by Aquinas.
He who enters religion does not make profession to be perfect, but he professes to endeavor to attain perfection; even as he who enters the schools does not profess to have knowledge, but to study in order to acquire knowledge.
– Summa Theologica, II-II, 186, 2
Knowledge is loved not that any good may come to it but that it may be possessed.
– Summa Theologica, I, 60, 3
As the Philosopher [Aristotle] says, “one knowledge is preferable to another, either because it is about a higher object, or because it is more certain.” Hence if the objects be equally good and sublime, that virtue will be greater which possesses more certain knowledge. But a virtue which is less certain about a higher and better object, is preferable to that which is more certain about an object of inferior degree. Wherefore the Philosopher says that “it is a great thing to be able to know something about celestial beings, though it be based on weak and probable reasoning”; and again that “it is better to know a little about sublime things, than much about mean things.” Accordingly wisdom, to which knowledge about God pertains, is beyond the reach of man, especially in this life, so as to be his possession: for this “belongs to God alone”: and yet this little knowledge about God which we can have through wisdom is preferable to all other knowledge.
– Summa Theologica, I-II, 66, 5
Perfection of moral virtue does not wholly take away the passions, but regulates them.
– Summa Theologica, I, 95, 2
The purpose of human law is to lead men to virtue, not suddenly, but gradually. Wherefore it does not lay upon the multitude of imperfect men the burdens of those who are already virtuous, namely, that they should abstain from all evil. Otherwise these imperfect ones, being unable to bear such precepts, would break out into yet greater evils.
– Summa Theologica, I-II, 96, 2
Perhaps not everyone who hears this word “God” understands it to signify something than which nothing greater can be thought, seeing that some have believed God to be a body. Yet, granted that everyone understands that by this word “God” is signified something than which nothing greater can be thought, nevertheless, it does not therefore follow that he understands that what the word signifies exists actually, but only that it exists mentally.
– Summa Theologica, I, 2, 1
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 put in motion 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.
– Summa Theologica, I-I, 2, 3
It is impossible for any created good to constitute man’s happiness. For happiness is the perfect good, which lulls the appetite altogether; else it would not be the last end, if something yet remained to be desired. … Hence it is evident that naught can lull man’s will, save the universal good. This is to be found, not in any creature, but in God alone. … Therefore God alone constitutes man’s happiness.
– Summa Theologica, I-II, 2, 8
A certain participation of Happiness can be had in this life: but perfect and true Happiness cannot be had in this life. … Since happiness is a “perfect and sufficient good,” it excludes every evil, and fulfils every desire. But in this life every evil cannot be excluded. For this present life is subject to many unavoidable evils; to ignorance on the part of the intellect; to inordinate affection on the part of the appetite, and to many penalties on the part of the body. … Likewise neither can the desire for good be satiated in this life. For man naturally desires the good, which he has, to be abiding. Now the goods of the present life pass away; since life itself passes away, which we naturally desire to have, and would wish to hold abidingly, for man naturally shrinks from death. Wherefore it is impossible to have true Happiness in this life.
– Summa Theologica, I-II, 5, 3
The greatest of all pleasures consists in the contemplation of truth.
– Summa Theologica, I-II, 38, 4
All that I have written seems to me like straw compared to what has now been revealed to me.
The Daily Idea aims to make learning about philosophy as easy as possible by bringing together the best philosophy resources from across the internet. To get started, check out this organized collection of 400+ articles, podcasts, and videos on a wide range of philosophical topics.
A Collection of the Greatest Philosophical Quotations
A History of Western Philosophy in 500 Essential Quotations is a collection of the greatest thoughts from history’s greatest thinkers. Featuring classic quotations by Aristotle, Epicurus, David Hume, Friedrich Nietzsche, Bertrand Russell, Michel Foucault, and many more, A History of Western Philosophy in 500 Essential Quotations is ideal for anyone looking to quickly understand the fundamental ideas that have shaped the modern world.