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The Domestic Aquinas Project

Making the Summa Applicable to Families

Prima Pars

Question 7: The Infinity of God (4 Articles)


Article 1:  Is God Infinite?


Structure of the Argument:

St. Thomas uses this question to debunk the ancient philosophers that believed that matter was infinite and the first principle of life.  He takes the following approach:


1.  Everything that exists is made of matter and form.  A rock is the rock matter and the form that informs the rock.  A plant is plant matter formed by a plant form (or vegetative soul) that gives it the spark of life.  The form constricts the matter into a specific nature.  The form of man is the soul.  Our soul gives life to and forms our human matter.  Our form (a rational soul) constricts our human matter and we have a human person.  Matter is perfected by the form it receives.  The form is made finite (is constricted) by the matter.


2.  God is the author of all being.  He gives being (existence) to every single thing.  As the perfection of being itself, He can’t be constricted or contained by any physical thing nor he can be the form of any matter as He is the one giving being to that matter in the first place. 


3.  Thus, God must not have a body and must thereby be infinite.



Family Take Home:


The concept of an infinite being is wonderful to discuss with the

children.  First and foremost, they must realize that there cannot

be two infinite beings.  For an infinite being is everywhere.  There

is nowhere where that being is not.  Quite simply, there is no room

for a second infinite being. 


The result is that God’s presence is everywhere, in varying degrees

of course, but everywhere.  This means we can talk to God at any

time.  It means that we can know that He knows where we are at

all times because He is infinite.  It means He can read our

thoughts, know our intentions and know exactly how our sausage is digesting.  And all of this is excellent, because God is perfect, which means He loves us perfectly and wants our best perfectly.


Thus, we can trust Him perfectly.

Q. 7: Article 2: Whether anything but God can be essentially infinite?


Structure of the Argument:


Simply put:  Anything that is infinite must have a beginning.  God is the beginning of everything and thus is the only thing that can be infinite.


However, things can be relatively infinite. 


  1. Matter:  in regards to matter, lets say a tree, the matter of the tree receives the form of the tree at the time of its becoming.  The matter of the tree is contracted by the form and is thus finite.  However, it can have an infinite number of shapes.

  2. Form:  forms are also finite as they come to being

  3. when co-existing with matter.  However, some forms,

  4. like angels or the human soul (the form of the body)

  5. are not or may not be contracted by matter or a body. 

  6. These are relatively infinite.  Angels have a beginning,

  7. but no end – in this way they are infinite.


Only God is absolutely infinite.  He is the only thing that is

uncreated or self-subsisting. 


Family Take Home:


Children ask great questions when it comes to trying to

understand God. 


            Can God create something so big He can’t lift it?

            Can God make another God?


In answering these types of questions, the answer is more often than not that God can’t do non-sensical things or nonsense.  Asking ‘if God can create a rock so big He can’t lift it’ is like asking if He can walk and not walk through a door at the same time. 


Understanding infinity helps a child realize that there is only and that there can only be one God.  If being absolutely infinite means that one has no beginning and no end, then to create another God that has no beginning would be impossible.  God can’t create something to be uncreated.


The absolute infiniteness of God extends to His presence, His power, His knowledge, His wisdom, His perfection and to His essence insofar as He has not beginning and no end.  He is the beginning and the end.  All things begin with Him and terminate in Him.


There is nothing relatively infinite in God.

Q. 7: Article 3: Whether an actual infinite magnitude can exist?


Structure of the Argument:


In the last article St. Thomas proved that nothing but God could be infinite in its essence.  In this article he is looking to understand infinity even more by seeing if anything can be infinite in its shape or quantity.


To do this we have to look at a body, a thing in two ways: mathematically, in respect to its quantity by measurement; and naturally, by means its form and matter.


1.  Naturally

We know already that any created body cannot be actually infinite because it is constricted by the form given to it.  Every created body has what is called a substantial form – our soul is the substantial form of our body.  Treeness is the substantial form of the matter to make a tree.  However, there are accidents that exist not on their own but because there is a substantial form.  Skin colour is an accident.  If there was no skin, there would be no skin colour.  Quanity or size is another type of accident.  If there was no body, then there would be no size of that body.  Every body has a determinate size and quantity based on its nature or substantial form.  Ants will never grow to immense sizes for its quantity is determined by its nature.  Because of this, no created body can be infinite naturally. 


St. Thomas also addresses the argument in regards to motion.  All finite bodies can potentially move from one place to another because they are not already in the place they are moving to.  An infinite being would be everywhere and thus there would no place for it to move to.  Thus infinite beings are unmovable and finite beings are movable.


2.  Mathematically

If we consider a body mathematically then we have to consider it actually existing and having a quantity and if it has a size and shape then it is finite.  Its size and shape are its boundary or limit.  The objector suggests that since we can in theory always divide a body like a block of cheese in half and though the pieces get smaller and smaller we can (if we could) continue half the piece of cheese infinitely, then can we not also double the size of a body infinitely?  St. Thomas states that even here, if we are adding to something we will eventually come to the place where it is wholly present.  Once the block of cheese is a whole block of cheese again we can’t double it anymore.  Here again, a body can’t be infinite if it has a size or quantity.


Family Take-Home:


The point of these articles is to understand infinity so that we can in some way try to wrap our understanding about what God is. 


The key point here for our children is that God is unmoved.  He is unmoved because there is no place where He is not. Thus there is no place to move to.   So when Jonah tries to run from God, He finds God in the storm, in the belly of the whale and in Nineveh.  The Psalmist knew of this well:


Where can I go from your spirit?
    Or where can I flee from your presence?
8 If I ascend to heaven, you are there;
    if I make my bed in Sheol, you are there.
9 If I take the wings of the morning
    and settle at the farthest limits of the sea,
10 even there your hand shall lead me,
    and your right hand shall hold me fast.

11 If I say, ‘Surely the darkness shall cover me,
    and the light around me become night’,
12 even the darkness is not dark to you;
    the night is as bright as the day,
    for darkness is as light to you.

Q. 7: Article 4: Whether an actual infinite multitude can exist?


Structure of the Argument:


In the the final article on infinitude, St. Thomas looks whether there can be an infinite number of things.  He looks at this in two ways:


1.  Absolutely

Can there actually be an infinite number of fish in the sea? Or an infinite number of grains of sand?  His answer is 'no'.  Nothing can exist actually and be infinite in number.  For numbers only exist because there are objects to count.  Everything in existence is finite and can be counted.


2.  Mathematically

However, numbers can be potentially infinite.  Theoretically you can always add one more number.


Family Take-Home:


The point of these articles is to understand infinity so that we can in some way try to wrap our understanding about what God is. 


The key point here for our children is that God created the world.  Thus everything is finite.  Nothing created can be infinite.  Thus, only God is absolutely infinite.

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