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The Domestic Aquinas Project

Making the Summa Applicable to Families

The sacred duty of parents is to educate our children in the faith and in right thinking.  If St. Thomas is our Church Doctor of right thinking then it behooves us parents to get to know him better. 

At the Council of Trent, his Summa Theologica was placed on the altar second only to the Holy Scripture.

Pope Leo XIII admonishes all the faithful to learn the teachings of St. Thomas Aquinas and that it would bring security and unity to the family.

"Domestic and civil society ...  would certainly enjoy a far more peaceful and secure existence if a more wholesome doctrine were taught in the universities and high schools-one more in conformity with the teaching of the Church, such as is contained in the works of Thomas Aquinas." - Pope Leo XIII

My goal is to walk through the teachings of the St. Thomas Aquinas and provide practical ways of integrating his teachings into our family life and into the education of our children.  It all begins with forming our thinking, changing and correcting our language and then finding opportunities in family life to reinforce right thinking.

For Example: St. Thomas discusses the principle of how the good is diffusive of itself (CG 1.37).   The opportunity arose during Ember Days to look at the changes in nature with my children.  We saw how all plants and trees desired to reproduce themselves. Here is the principle in action!  All things good want to share their goodness.  It is a sign of the perfection of their nature.  

The format:

a.  I will use the translation as provided by the Dominican friars here.

b.  I will summarize the sense of the questions and articles, which may include leaving out some questions here or there.

c.  I will provide strategies/opportunities/ideas of how to integrate the teaching into family life.


We begin where St. Thomas begins: 

Prima Pars

Question 1: Treatise on Sacred Doctrine

Article 1: Do we need Sacred Doctrine at all if we already have the discipline of philosophy?

Summary of Argument: 

1.  Man is made for an end higher than himself. He is made for communion with God and thus to reach an end higher than himself, he needs a Revelation given that is from something higher than his own reason.  For in order to reach a goal, the goal must be known and to know certain aspects of God (He is triune) we needed Divine Revelation. 

2.  Man can come to some knowledge of God by reason alone, but this is a difficult route to take and would be done successfully by only a few and mixed with many errors.  Thus, for the sake of the many, Divine Revelation was given for our salvation. 

3.  Man's salvation depends on the knowledge of the truth.  Hence, it was most fitting for God to give us Sacred Doctrine and in doing so man will be more surely saved.

Taking it Home:

1.  This very first question can lead to a discussion of one of the most important questions, namely, if God has given us Sacred Doctrine, how do we come to know it? How do we know it has been preserved correctly by fallible man? The answer is simply that unless God was to provide an institution by which the doctrine was to be disseminated throughout the ages infallibly, we would have no idea what that truth would be now.  And, Deo Gratias, He did provide an institute: The Holy Catholic Church.

2.  Ask your children how it would be possible to know there is a God without the Catholic Church, parents, teaching, or the Bible? How can man, through reason, know there is a God? 

Answer: everything must have a beginning.

3.  With my children, we talk a lot about the order of nature:

mineral, animal, man, angel, God.  Our end, our goal, that

which we have been created for is not simply trying to

happy here on earth.  Because we have been created to

participate in the Divine Nature, we have a higher end - a

supernatural end.  Now here's the take home: my boys

always tell me they would just be happy if they could have

a house full of Lego.  I get to respond by explaining that

their happiness isn't going to be found here on earth in

things, for they are created for something higher.  

Prima Pars

Question 1: Treatise on Sacred Doctrine

Article 2: Is Sacred Doctrine a Science?

Summary of Argument: 

1.  All of us have first principles that are known by the 'natural light of intelligence'.  The first principles are what we use to know everything else.  A baby has the first principles - for eg: he knows that his mother is not his father or put another way: one cannot be and not be at the same time.  The baby has the power to differentiate.  Many sciences proceed from these first principles like mathematics.  

2.  Some sciences proceed as principles from a science with higher principles.  St. Thomas gives the example of music proceeding from the principles of arithmetic.  

3.  Sacred Doctrine proceeds as the second science.  It comes from principles that are higher than our own light of reason, namely the intellect of God Himself.  "It is established on principles revealed by God."

Taking it Home:

                   The study of Sacred Doctrine is a legitimate field of study.  The key here though, is that                  it is        not only just legitimate, it is the highest as it flows from the Author of all                                                knowledge.  Thus, it is important to make the Catholic Faith both the footstool                                and the crown of our children's education. At the end of the day, we have the                                     Sacred Doctrine available to us parents.  Now it is essential that we make time in our                            children's education for the study of it.  

One might even suggest that we leave our Cartesian tendencies and spend less time on math and more time on theology as in the end, as it is the study of God that will lead our children to salvation.

Article 3: Is Sacred Doctrine One Science?

Summary of Argument: 

The question is posed because the objectors insist that theology should be about God only and thus all the stuff about man and angels and creatures in Sacred Doctrine should be another type of science. 

St. Thomas disagrees and states it is one science because a thing is considered primarily under its formal aspect. This means that when I study a man, I study man formally and everything else that falls underneath that category such as his digestive system and his need for relationship. 

In the same way, the form or stamp on Sacred Doctrine is that it is Divinely revealed and this makes it one science.  But truly, since everything is created by God and all creation points to Him, everything, absolutely everything can be discussed here.  It is the queen of all sciences so to speak.

Taking it Home:

The great part of this article is the end.  This Divine Science “extends to everything.”  This principle is reflected and put into use by Pope Pius XI in his encyclical Divini Illius Magistri where he places all subjects of study under the auspice of the Catholic Church:


“first of all education belongs preeminently to the

Church, by reason of a double title in the supernatural

order, conferred exclusively upon her by God Himself;

absolutely superior therefore to any other title in the

natural order.”

In the same way, all studies we engage in with our

children (or without them) come under the authority of 

Divine Revelation as interpreted and handed down by the

Catholic Church.  We study through the lens of faith.  We

wear Catholic glasses (proudly) and see through the

world filtered through the Queen of all sciences because this is the RIGHT way to see the world.  Thus, every subject, every activity, every assignment that our children engage in, should be done in this light.  And, it does no harm to remind our children or to consistently be drawing parallels or allusions to the faith in their studies.

Article 4: Is Sacred Doctrine a Practical Science?

Summary of Argument: 

The question here is about whether sacred doctrine is a practical or a speculative science.  The objector would say it is a practical science because it a science that is ordained to action – it gives us admonitions to do things and act a certain way, to love. 

St. Thomas, however, disagrees.  Sacred Doctrine as a science must be speculative simply because it is about God.  Sure there are calls to action and practical items involved, but these are merely consequences that follow on studying God Himself. 

Taking it Home:

The take home this time is in the final sentence of his response: “man is ordained by [his actions] to the perfect knowledge of God in which consists eternal bliss.” 

All our acts should lead us to God.  EVERYTHING we do and say and see and touch and think and smell points us to God.  In Him we live, and move and have our being (Acts 17:28). 


This again is a hint to us parents that we need to, unabashedly, point out God in our daily lives.  He is the centre of our home, our family, our existence – knowing us more than we know ourselves.  He even knows how my food is digesting (or not) and how much blood flows through my veins.  I move and breathe because He gives me life.  He is my all in all.

Article 5: Whether sacred doctrine is nobler than other sciences?

Summary of the Argument:

The study of Sacred Doctrine is partially speculative and yet also practical and in both of these areas it is greater than all the sciences.  Why?

1.  A speculative science is considered to be a great science when it has a great amount of certitude.  This is probably why we fight so hard to have our students at school learning math every day.  Yet, the study of Sacred Doctrine is greater and has more certitude than even math.  For math gets its certitude from the light of human reason.   Sacred Doctrine gets its certitude from the Divine Wisdom.  It not only deals with that which is in the grasp of our intellect, but with He who transcends our intellect.

2.  A practical science is considered great if it is ordained to a great purpose.  The study of medicine is greater than the study of volcanic rock for medicine leads to the health of humans.  The purpose of the practical aspects of studying theology is to

lead us to eternal bliss … there is no greater purpose.

Taking it home:

An inquisitive and observant child would object to this argument

if they knew of Protestantism.  They would suggest that if

theology is so certain, how come so many Christians disagree?

Why then are there so many denominations all claiming to know

the truth? 

St. Thomas replies: well … the certitude of the science comes from the fact that it comes immediately from God so there is no error and absolute certitude because God cannot lie or deceive.  Error arrives on the scene with our fallibility.  So, God, knowing that we get things wrong, and that this science of the knowledge of Himself was too important to let it go awry, instituted a Church which he divinely protects with infallibility when it comes to teaching this Sacred Knowledge.  That Church is the Catholic Church. 

Article 6:  Is Sacred Doctrine the same as Wisdom?

Structure of the Argument:

First of all we have to understand what wisdom is.  What does it mean to be wise? 

-  A prudent man is called wise when he makes decisions that work towards an end that is fitting and good. 

-  A wise man is one who judges, and one who judges is one who knows the area well in which he is judging.  You cannot judge well if you don’t have much knowledge in the area you are judging. 

-  Thus, the one who is most wise is the one who has the knowledge of the highest things to be known, namely, Divine things.

Sacred Doctrine treats God as the highest of all, the beginning of all, the uncreated creator.  And since Sacred Doctrine comes from God, who knows all things, it must be wisdom.  All of our knowledge in the natural realm is set in order by the Divine knowledge.  It is the science that can judge all other sciences as it is the knowledge of the highest. 

Taking it Home:

The take-home here is found in St. Thomas’ reply to the

second objection.  He states emphatically, that God’s Divine

Revelation is the judge of all sciences and thus “whatsoever

is found in other sciences contrary to any truth of this science

must be condemned as false.”  This again brings us back to

the crux of all these articles, namely, that God has revealed

Himself to man and because man is fallible, He gave infallible

authority to “bind and loose” to Peter and the apostles and

those who follow in their office.  This ‘binding and loosing’ is

the authority to decide the truth concerning God and to judge all sciences.  For example: any science that claims a beginning of creation without God is condemned as false.  Any science that would claim to manipulate or change nature (like contraceptives, gay marriages) are condemned as false.  Thank God we have the infallible teaching of the Catholic Church to guide us through all the falsehoods that arise in our times!

Article 7:  Is God the principle object studied in this science

Structure of the Argument:

We can’t know the essence of God.  He is infinite and a finite mind can’t grasp that which is infinite.  If this is so, the objector would state that God really can’t be the object of what we are studying in theology, but it must be something we can know, namely, the effects of God that we see and experience. 

God is, however, the object of theology.  In all that we study in theology, His effects and His revelation of Himself are all in Him.  All begin and end in Him. 

The object of something is found under the aspect or the condition in which it is received.  For example: colour is the object of sight.  Everything that is seen is seen through the aspect of colour.  Light hits our eyes and we see the light wavelengths that are reflected in a specific colour.  In the Sacred Science of theology, we study everything and see everything through the aspect of God Himself as He is the beginning and end of everything.  Through God we study God so to speak.

Taking it Home:

                                                                         The key take-home with this small article is that we                                                                                  can’t define God.  A definition leads us to know the                                                                                 essence of something.  We can’t know the infinite                                                                                     essence of God.  Thus, we must come to know Him                                                                                 through His goodness, His creation, His grace and                                                                                     blessings.  And truly, this points to a good God.  This is                                                                            where Ember Days become a great feast day for                                                                                      families.  Ember Days happen 4x/year are in the old                                                                                liturgical calendar.  They happen at the change of the                                                                              season.  We take the feast day and head outside with                                                                              the children and discover ways that nature teaches us     about our Creator.  We look at the perfection of a snowflake, the rhythm of nature as trees prepare for winter (like a baptism) to rise to new life in the spring.  And there are hundreds more ways to learn about God from creation!

Article 8: Does Sacred Doctrine use arguments to come to conclusions?

Structure of the Argument:


Theology takes its principles, its articles of faith and uses them to argue to further conclusions like any other science. An example of this is the doctrine of indulgences.  Indulgences are a tertiary doctrine logically concluded to by prior principles. 


When it comes to arguing the faith with someone like a Muslim, the opponents must concede to the fact that there is divine revelation.  If the opponent is an atheist and doesn’t believe that there is any divine revelation or authority, then the faith can’t be argued from this position, but simply by answering objections against faith itself.  In other words, arguments in theology can lead us to further conclusions in the faith, but we can’t have arguments for the articles of faith themselves – they simple just are.  If we could argue by human reason to get to the articles of faith (e.g.: God is triune) then we wouldn’t have any use for faith.  We can show that it is not unreasonable that God is triune, but we can’t scientifically prove this article faith.  It is simply something we believe has been divinely revealed and that we hold to be true.


Taking it Home:


Authority is the number one issue to be

understood when it comes to the faith.  If we

believe that Scripture is the sole authority

(sola scriptura) as our protestant brothers do

, then we have to ask who had the authority

to put the Bible together and to decide what

books should be in the Bible.  The answer is

historically there for us: the Catholic Church. 

Thus, the real leap of faith is simply believing

that Christ established a Church through

which to pass on the truth about Himself

infallibly.  Authority is the key. 


This means, that we as parents must make a concerted

effort to teach our children about authority in the family. 

Since the family is a microcosm of the Church, what the children

learn about authority in the family they will automatically transfer

over to their understanding of authority in the Church.  Here is where

the father takes a large role.  The father is the head of the home.

The father needs to walk the line of being strong in his leadership

and yet not be domineering.  In other words, the children need to

learn to trust him.  Trust is given as young children and then it should grow as the children grow.  They need to trust that we fathers have their best interests at hand, that we will protect them, that we won’t place them in situations that they can’t bear, that we will love them unconditionally, and so forth.  This trust in their natural father will make it a far easier to transition to trust their supernatural father, our Pope and also our Divine Father Himself.


The unfortunate part is that many homes are fatherless.  A home without a father means it is more difficult to know God as father (but not impossible).

Article 9:  Should Scripture use metaphors?


Structure of the Argument:


The main objection for the use of metaphors in Scripture is that it is unfitting to learn about Divine things from material, earthy things.  We know that Scripture does use the natural world to help to bring an understanding of our infinite God.  Is this is a fitting thing to do? 


St. Thomas states that, it is fitting.  It is fitting because man is a part of creation and made of matter and thus everything he learns and knows comes through his senses.  And secondly, that metaphors help make the truths about God accessible to those who struggle with understanding intellectual things (like our children).


Taking it Home:


The take home here is obvious:  use

metaphors to help your children

understand the faith!  There are a myriad

of ways to do this and I’ll provide a few


  1. Spend time in the mountains with your
    children.  The mountain that is firm and
    unmovable and sustaining eco-systems
    and life is a great metaphor for God. 

  2. Use candles when you pray.  The light from a candle drives away darkness – this is a great metaphor for Christ is the light of the world and a constant reminder of His light in us.

  3. Garden with your children.  The amount of metaphors that come about when you begin to weed are numerous.  Weeds (sins), if we let them take root in our hearts are very difficult to get out – especially dandelion weeds.

Article 10:  Can a word in the Bible have several senses (meanings)?


Structure of the Argument:


The objection is mainly that having words or sections in the Bible having more than one meaning would bring confusion and deception, and that the Bible should state the truth purely and matter of fact. 


Now, we know this isn’t so.  We have 40,000 protestant denominations all interpreting Scripture differently.  The operative word being ‘interpreting’.  It needs to be interpreted and applied.


St. Thomas states that God has attached meaning to words and also to the things signified by the words.  For example: the word Jerusalem means a city in Israel, and the city of Jerusalem symbolizes the Church.  The first meaning is called the literal sense: what the words actually mean – and this is always the foundation, the starting point, the intention.  The second meaning found when things in Scripture have a symbolic meaning is called the spiritual sense and this spiritual sense is divided into three types:

1.  Allegorical Sense: when the Old Testament is prefiguring the new.  E.g.: that there was a flood and Noah was saved on the ark is the literal sense.  That the flood symbolizes baptism (I Peter 3:18-21) is the allegorical sense.


2.  Moral Sense: when the works of Christ signify what we ought to do today.  E.g.: am I the Good Samaritan or like the priest that passes by?


3.  Anagogical Sense:  when the things signify

something pertaining to eternal glory. 

E.g.: Jerusalem can also symbolize the

Heavenly Jerusalem.


And no confusion is found with all these

senses available for all the spiritual senses

must be based on the literal sense. 


Taking it Home:


First thing is first: we must be reading the Bible with our children.  How can this be done? Here is what we do:


1.  In the mornings at our prayer time, we’ll read a story from Scripture.  Our children are young and are simply learning the stories, the timeline of the Bible.  We haven’t found a great Catholic children’s Bible yet, so we use ‘The Picture Bible’ by David Cook.  It is protestant so it doesn’t have the whole Bible available, but he does add the history of the Maccabees so that is something.  During the story reading we learn the literal sense, and then apply it to our lives using the moral sense.  Sometimes we can connect an allegorical sense and it is fun to look for ways in which the Old Testament foreshadows the new.

2.  Scripture Memorization: We have our children memorize passages.  A good place to begin is Matthew 5 and 6 – the sermon on the mount. 

3.  Learn to pray the Psalms together.  We pray a Psalm together in the morning knowing that out there, somewhere, someone is needing the words of this Psalm prayed on their behalf.

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