St. Thomas Aquinas and the Light of Reason

Feast Day: January 28
A cross of light at Moose Falls, Yellowstone. Photo by author.

“How do you listen to God?” I think that’s the best question I got from a student on my school’s retreats. It’s not an easy one. You could have a vision of an ineffably luminous being speaking to you in a booming voice. It can happen. It’s not the way I normally hear Him. If you do, that’s excellent, but make sure you’re not giving into your mind’s capacity for self-deception or the deceptive glamour of evil spirits (as the Desert Fathers like Simeon Stylites would add).

I’m not going to give a full answer in a single blogpost, but I think good listening means not neglecting any part of your humanity. We each have a spiritual intuition that is part of our consciences; often in prayer an intuitive conviction emerges in me about what I should do. I can, like St. Ignatius, also consult my feelings when I imagine different paths or outcomes—what gives me peace and what leaves me feeling empty? And I am a social animal, so what do wise people around me say when I ask? Are all of these things pointing to the same place?

The final part of who I am and how I listen to God’s voice is reason. God’s gift of reason forms an essential part of our nature. He calls us to use our reason to know Him and know our way forward. The proof of this for early Christians was how pagan philosophers already had theorized an eternal being, an eternal soul, and much of Christian ethics just using pure reason (albeit with lots of disagreements). There is a reason that the university owes its invention to the medieval Church. Reason alone may not be enough—we need grace and we need love too—but it is good and needed.

Today’s saint is Thomas Aquinas. He is one of the greatest examples of reason seeking God in the Catholic church.

Saint Thomas Aquinas Aided by Saints Peter and Paul, by Bartolomeo degli Erri (active 1460–79). Metropolitan Museum of Art Open Access.

Thomas’ Life

It wasn’t really Thomas’ desire to become a priest that caused his wealthy family to lock him in a tower room and then toss a prostitute in it with him. They offered to finagle him leadership of a wealthy monastery—something socially acceptable and local where he could use his influence for the family’s benefit. But no, he wanted to join the Dominicans, this new-fangled group of zealous preachers who could be assigned anywhere and who lived in poverty.

The ham-fisted attempt to thwart the quietly stubborn man worked as well as could be expected, That is, it did not work at all. Thomas immediately grabbed a branch from the fire to chase out the poor woman and easily outlasted his family in the waiting game. He joined the Dominicans, went to the University of Paris to be educated, and became one of the top three or four most influential theologians in Christian history.

He had studied with St. Albert the Great, another man whose path to holiness came through his mind. Albert used logic to study everything from music to minerals, all of which filled him with wonder at God and the beauty with which He suffused creation. Thomas focused more on theology proper, but discussing God in his grand Summa theologiae inevitably led to talking about Christ incarnate, salvation, human nature, and their consequences ethics and law. He dedicated his life to teaching and this rational exploration of God and our relation to Him and the world until he died in 1274.

Thomas followed a long tradition of rational theology, but his synthesis of so many different building blocks into a single beautiful architecture has inspired centuries of later thought. He had a prodigious intelligence. He would dictate four separate treatise at once to four scribes, giving a couple sentences to one, then turning to the next while the first was still writing, and so on, somehow keeping straight what he was saying in each.

On a side note, he really did need scribes—he had absolutely illegible handwriting. One of my grad school professors told me that there are just three people in the world today who claim to be able to read it, and those three only get away with it because they already know what it is supposed to say!

S. Thomas d’Aquin (St. Thomas Aquinas), March 7th, from Les Images De Tous Les Saincts et Saintes de L’Année (Images of All of the Saints and Religious Events of the Year),
by Jacques Callot, 1636. Metropolitan Museum of Art Open Access.

The Sanctity of Thomas Aquinas

I’m personally inclined to the intellectual pursuits and may even be guilty of overthinking things on rare occasion. One thing I love about the saints is that they confirm that there is a variety of paths to holiness. A person can be a parent, a farmer, a monastery doorman, a king, or an academic, and there is a saint who somehow connects.

There are, of course, basic virtues that every Christian needs to practice such as charity to the poor and devotion to prayer. St. Thomas did those too. Without that life of prayer and giving away goods to the poor, I can’t imagine his intellectual pursuits could have transformed him into a man of wisdom and holiness. It is perhaps fitting that for many devout Catholics the words of his with which they are most familiar is a Eucharistic hymn: Pange lingua. The last verses of it are sung at Benediction after Adoration.

Simply knowing things doesn’t make one holy. Even knowing things about God is not enough (the devils know—and tremble! James 2:19). If, however, you let your heart be filled with wonder at what you find or work to understand, love, and help others, then you can find God in intellectual pursuits. No matter what you learn or research, let it be done out of love.

That is what Thomas did. And it filled him with a contemplative love and holiness that continues to enrich people’s lives. Whatever each of our vocations, may we do them for the sake of God and neighbor, alert to how it can make us grow in faith, hope, and love.

Chant of the Mystics: Pange Lingua – Divine Gregorian Chant – Eucharistic Hymn – Lyrics and Notes. Uploaded and sung by Patrick Lenk. YouTube. To read the Latin lyrics and English translation for Pange lingua, see