top of page

The Domestic Aquinas Project

Making the Summa Applicable to Families

Prima Pars

Question 11: The Unity of God (4 Articles)


Article 1:  Does 'One' add anything to being?


Structure of the Argument:

This question is asked because some ancient philosophers, like Pythagoras, believed that numbers signified the substance of being.  St. Thomas, here, wants to disprove this, but also to show that 'one' is used in a different way than the #1.

The argument is relatively simple: all individual things that exist are one.  The are a unity.  They are unified into one being.  This unity and oneness is protected insofar as they desire to stay a unit.  For e.g.: a human.  We are a unity of body and soul.  Our body is a unity of many many parts.  This unity of parts makes a substantial whole and is one.  Now, this body may be separated into parts - I may lose a finger or get my hair cut, but this doesn't effect the substantiality of my unity until my body dies and my soul and body are separated. 


If something is simply one (meaning not a compound - a thing made up of parts like a human) than that simple thing is one absolutely and can't be divided into parts.

To counter Pythagorus, if we were a whole unit, one, by something other than what we are - like the #1, then we would be one by that number and that number would need to be one by another number ad infinitum.  

Family Take Home:


The take home here need not be too complicated.  St. Thomas

is trying to emphasize that oneness, unity, can be applied both

to those things that have no parts (like God Himself) and

compounds like ourselves.  We are a unity of many parts and

that unity is ipso facto one.  Our body and soul are not two

different separate entities, but are one composite.  We are our

body.  We are our soul.  We are one.



Article 2:  Are 'one' and 'many' opposed to each other? 


Structure of the Argument:

Little Boy Standing Portrait
bottom of page