Summa of the Summa: The Essential Philosophical Passages of St. Thomas Aquinas' Summa Theologica Edited and Explained for Beginners Book

A Summa of the Summa of St Thomas Aquinas
By Peter Kreeft


Peter Kreeft provides with this work a readable summary of the extensive 'Summa Theologica'.
The original text in ancient language by Aquinas needs the footnotes provided by Kreeft to make it reasonably comprehensible.
And even so, it remains a challenge.

St Thomas Aquinas (1224-1274) in his Theological analysis, the questions raised are divided into six main chapters.

I will quote a few lines of the ones that attracted my attention:

1. The Sacred Doctrine.
-It was necessary for man's salvation that there should be the knowledge revealed by God, besides philosophical and rational theology built up by man.
-The sacred doctrine is a science. It is speculative rather than practical; it is more concerned with divine things than with human acts.

2. Proofs for the existence of God. (a few illustrative examples)
-Motion: Since nothing can move itself, there must be a first, Unmoved Mover, the source of all motion.
-Design: design can be caused only by an intelligent Designer, mindless nature cannot design itself or come about by chance.
-Time: Time must have a beginning, (the Big Bang, fifteen to twenty billion years ago) the act of creation presupposes a Creator.
-Existential: If there is no God, life is ultimately meaningless.
-Historical from Jesus: If God is unreal, Jesus has died on the cross for nothing.

3. The Nature of God.
-God is not a body. God is a spirit. Only children and pagans who cannot think abstractly think that God is a body. God is the first mover and is Himself not moved. Therefore it is clear that God is not a Body.
-God is in all things.
-Everything, in so far as it is good, is willed by God. In a particular case, we add that a man who is a murderer or dangerous to society, to kill him is good; that he lives an evil.

4. Cosmology. Creation and Providence
-By faith alone do we hold, and by no demonstration can it be proved, that the world did not always exist.
-Whether there is only one world? St Thomas replies: The very order of things shows the unity of the world. Those only can assert that many worlds exist who do not acknowledge any ordaining wisdom, but rather believe in chance, as Democritus, who said that this world, besides an infinite number of other worlds, was made from casual concourse of atoms……!
For the same reason it might be said that if He had made two worlds, it would be better if He had made three; and so on to infinity…!
-Whether the world is governed by One? St Thomas replies: The multitude is better governed by one than by several. Therefore the best form of government must be by One.
(The footnotes reverse this statement: St Thomas is not making a political statement here. In fact, he thinks the best political regime is the "mixed regime" of a democratic constitutional monarchy)

5. Anthropology. Body and Soul.
-For St Thomas, the soul is both a substance and a form. As a substance, it can exist of itself without the body. As the form of the body, it is the very life of the body.
-Whether the soul was produced by creation? St Thomas replies: The rational soul can be made only by creation. Nb. Parents generate their children's bodies, but not their souls.

6. Epistemology and Psychology.
-Whether one person can understand the same thing better than another can? St Thomas replies The better disposition of the body, the better the soul allotted to it. Some men have bodies of better disposition; their souls have greater power of understanding; wherefore it is said (De Anima ii.9) that it is to be observed that those who have soft flesh are of apt mind.
-Whether our intellect can know the infinite? St Thomas replies: Now in material things the infinite does not exist actually, but only potentially. Therefore infinity is potentially in our mind through it's considering successively one thing after another.
-Whether God is the first object known to the human mind? St Thomas replies: Since the human mind in the present state of life cannot understand even immaterial substances (angels), much less can it understand the essence of uncreated substance. Hence it must simply be said that God is not the first object of our knowledge.
-Whether the image of God is in man? St Thomas replies: There is in man a likeness to God; not, indeed, a perfect likeness, but imperfect.


7. Ethics.
The question of the Summum bonum, the greatest good, the final end, meaning and purpose of life.
St Thomas replies: (here the headlines only)
-It is impossible for man's happiness to consist in wealth.
-It is impossible for happiness to consist in honor.
-Man's happiness cannot consist of human fame and glory.
-It is impossible for happiness to consist in power.
-It is impossible for man's happiness to consist in the goods of the body or pleasure.
Whether some good of the souls constitutes man's happiness?
-We must say that happiness is something belonging to the soul, but that which constitutes happiness is outside the soul.
Whether one can be happy in this life?
-A certain participation of Happiness can be had in this life, but perfect and true Happiness cannot be had in this life.

-Of the Theological Virtues. Man is perfected by virtue, for those actions whereby he is directed to happiness. It is the oldest truism of this world: if you are good, you will be happy.

-On theological virtues: The Apostle says: Now there remain faith, hope, charity, these three.
The theological virtues direct man to supernatural happiness.
-Wisdom and charity are the two greatest virtues.

-All acts of virtue are prescribed by natural law; since each one's reason naturally dictates to him to act virtuously.


I wanted to read this book to complete my previous readings and knowledge, and I am not disappointed.
Even when I was often bothered by the extreme meticulous method of going into endless detail on every subject, when I thought one phrase would do, it is drawn out into three pages.
Next to the Bible, it gives the broadest possible outlook on Christian religion.

I would not recommend this book to readers who read for entertainment.
But it is a must-read for anyone interested in Theological Philosophy.