Duomo Press: Featured Book

Excerpts: The Primer on Aquinas

street sign
Street sign, Paris

santa sabina church
Basilica of Santa Sabina, Rome, where Aquinas began the Summa.

sabina plaque
Plaque, Basilica of Santa Sabina

sabina footpath
Footpath up the Aventine Hill in Rome to the Basilica of Santa Sabina

quoteBeing self-aware, thinking creatures, humans naturally ask questions. Why do we exist? Why do we continue to exist day after day after day? What sustains us in being? Aquinas asks these same questions. He then asks the primordial question: Why is there not nothing? He goes on to say that the mystery of existence holds within it yet another mystery: the cause of existence itself. These are questions anyone can ask, including scientists and theologians, and are as valid today as they were in the thirteenth century.


God isn’t made up of stuff. He isn’t comprised of matter that takes up space; he is not an object or an entity that exists in a certain locale. God is also outside time. God doesn’t have a beginning, a middle, or an end, no before and no after.

... According to Aquinas, while God is not defined or constrained by space-time, we are. Aquinas sees life in the universe as individual instances of matter popping up at specific times and in specific forms that can be recognized and categorized (e.g., cats, woodpeckers, people). And he says that these individual life forms change over time in sequential, predictable, and irreversible ways, having beginnings, middles, and endings, with only one phase happening at a time, in a specific order, triggered when their inherent potential runs into the world around them.


For Aquinas, goodness is a measure of this self- actualization. It is the degree to which we have become what we are drawn to become, by exercising the fullness of the nature of which we are in possession. All created things will seek to grow into their own natures, and by doing so exhibit their goodness. ... As Josef Pieper says in his book In Tune with the World, “the highest intensification of life, the absolutely perfect activity, the final stilling of all volition, and the partaking of the utmost fullness that life can offer, takes place as a kind of seeing.”


If all created things naturally seek to grow into their own natures and thereby exhibit their goodness, the thing that powers this is the gift of grace. Grace happens in our soul, and when it does, we are changed, as in a healing. In fact, Aquinas says in that the healing of the soul is the first thing that grace achieves (Summa Theologica, 1a2ae. 111. 3):

Grace does five things:
first, it heals the soul,
then it prompts us again to seek our true good,
it helps us to actually do the good we seek,
to persevere in our actions,
and finally to “come to glory.”

The Summa Theologica traces a framework that leads us from the initial question of why is there not nothing, to practical guidance on how to act, to the life of Christ, and to the meaning of the Eucharist, our ongoing source of healing grace.


If we could state how exactly a human soul is healed and what makes a person recommit to seeking their highest good, it would be much easier to explain what grace is and what sacraments do. But that is their purpose and function, to give grace, which is the healing of the soul, the recommitment to seek our highest good, and “a kind of rebirth or recreation taking place in the nature of our soul.”