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

by Peter Kreeft

A shortened version of Kreeft's much larger Summa of the Summa, which in turn was a shortened version of the Summa Theologica. The reason for the double shortening is pretty obvious: the original runs some 4000 pages! (The Summa of the Summa was just over 500.) The Summa is certainly the greatest, most ambitious, most rational book of theology ever written. In it, there is also much philosophy, which is selected, excerpted, arranged, introduced, and explained in footnotes here by Kreeft, a popular Thomist teacher and writer. St. Thomas Aquinas is universally recognized as one of the greatest philosophers who ever lived. His writings combine the two fundamental ideals of philosophical writing: clarity and profundity. He is a master of metaphysics and technical terminology, yet so full of both theoretical and practical wisdom. He is the master of common sense. The Summa Theologica is timeless, but particularly important today because of his synthesis of faith and reason, revelation and philosophy, and the Biblical and the classical Greco-Roman heritages. This little book is designed for beginners, either for classroom use or individually. It contains the most famous and influential passages of St. Thomas' philosophy with copious aids to understanding them.

Genres: Philosophy, Theology, Religion, Catholic, Nonfiction, Christian, Faith

206 pages, Kindle Edition

First published January 1, 1485

About the author

Peter Kreeft is an American philosopher and prolific author of over eighty books on Christian theology, philosophy, and apologetics. A convert from Protestantism to Catholicism, his journey was shaped by his study of Church history, Gothic architecture, and Thomistic thought. He earned his BA from Calvin College, an MA and PhD from Fordham University, and pursued further studies at Yale. Since 1965, he has taught philosophy at Boston College and also at The King’s College. Kreeft is known for formulating “Twenty Arguments for the Existence of God” with Ronald K. Tacelli, featured in their Handbook of Christian Apologetics. A strong advocate for unity among Christians, he emphasizes shared belief in Christ over denominational differences.

Reviews

[Jacob Aitken · Rating 5 out of 5]

Kreeft, Peter. The Shorter Summa. San Francisco: Ignatius Press, 1993.

Introduction

On one hand, there is no substitute for reading Thomas Aquinas himself. If one must have an abridgment and/or guide, then Peter Kreeft’s longer Summa of the Summa is the best bet. But if that option is already available, is there any point to a Shorter Summa? Yes, but maybe not for all readers. Although the Summa of the Summa gives the reader everything he needs to know, it is nonetheless daunting. A Shorter Summa, by contrast, introduces the reader to medieval thought, gives the reader Thomas’s exact words, and avoids the more complicated discussions.

Epistemology

With respect to our dispensationalist friends, the best way to look at Thomas’s epistemology is by using charts.


Three Acts of the Mind
Understanding
Judging
Reasoning

Metaphysics

Existence of God
Kreeft makes the distinction between necessary existence, which applies to God, and our knowledge of that necessary existence. The predicate is included in the essence of the subject (1,2,1). God’s existence is not self-evident to us because we do not know the essence of God.

These articles are preambles to faith, not articles of faith (1, 2, 2).

Proof from motion: “Motion is nothing else than the reduction of something from potentiality to actuality.” Whatever is in motion is put in motion by another, but this cannot go on to infinity. In other words, change occurs. But what changes must be actualized by another, and this other will either be purely act or an admixture of act and potency. It is important to note what Thomas is not saying at this point. He is not saying that this goes backward in a linear fashion to a First Cause, with creation having its first moment. Rather, this series of causes is hierarchical in structure. The later terms depend on the (continued) existence of the first term. For example, if car A hits car B which hits car C, car A is the first cause in this linear series. If, after the accident, car A were to disappear, the damage would still be done. This is not what we mean when we apply hierarchical causality to God.

Simplicity of God

God cannot be made of parts if he is the first being, for who, then, would have put him together? Moreover, as he does not have potentiality, he cannot be actuated by anything else.

The existence of God in things.

God is in all things, not as essence or accident, but “as an agent is present in that upon which it works” (1, 8, 1). He is in all things as the cause of their being.

The Will of God

Does God’s will have a cause? No. As God by one act understands everything in his essence, so by one act he wills all things in his goodness (I, 19, 5).


The Providence of God

Providence does not impose a necessity on things because not all things have an inherent necessity. Some have necessary causes, others contingent causes (I, 22, 4).

Epistemology and Psychology

“Free will is the cause of its own movement, because by his free will man moves himself to act. But it does not of necessity belong to liberty that what is free should be the first cause of itself” (1, 8, 31).

Conclusion and Summary

Nothing substitutes for reading Thomas, preferably in large–very large–amounts. If one were to have to choose for an abridgment of Thomas, then Kreeft’s larger work is the one to read. Nonetheless, there is something useful about this shorter Summa. And Kreeft is always fun to read.

[Abby Emilyn · Rating 5 out of 5]

I loved how logically and systematically Aquinas presented his arguments–and Kreeft's insights, as usual, were thoughtful, helpful, and witty. Not bad for two Catholics ;)

[Matt Pitts · Rating 5 out of 5]

Few will ever read the full Summa, but why let the Summa’s daunting size keep you from encountering the brilliant theological and philosophical reasoning of Aquinas?

Peter Kreeft is an able and enthusiastic guide who, like all good guides, mostly stays out of the way unless you need him and consistently leads you to important places. It’s worth noting that the subtitle indicates that philosophy, not theology, determined the selection here. Consequently you will not find passages on the missions of the persons of the trinity or discussion of the person and work of Christ (though you find passages on God more generally), but you will find passages on ethics and free will.

[lydia · Rating 4 out of 5]

cohesive and pretty clear for a dead philosopher 😂😂 this edition was really nice and “pocket sized” if you will, and i’m glad i’ve dipped my toe into the holy water of thomas aquinas. 4/5 stars

[Phoenix · Rating 2 out of 5]

NOT the Cliff's Notes Version

While I enjoyed Kreeft's introduction this is not an overview of the Summa or even a Reader's Digest version. It's a shorter version of Kreeft's Summa of the Summa which I'm currently enjoying immensely. Essentially it's a selection of excerpts for a specific course, as designed by Kreeft at Boston College, and if this is ALL you are interested in then rate it 5* - it is worth buying and your professor will fill in anything extra you might need.

The book contains 25 of Aquinas' 189 Questions and there are 7 sections, which cover the nature of God, the soul, free will and some aspects of ethics. The length of each chapter in the A Summa of the Summa: The Essential Philosophical Passages of St Thomas Aquinas' Summa Theologica is usually 2-5 times longer, though Questions 2 (The Existence of God) and Q2 (Existence of God) and Q2 in Ethics (Man's Happiness) look to be the same. The one advantage, a smaller form factor so that it's easier to carry around, becomes irrelevant if purchased in Kindle format.

My advice, given the relatively small difference in price, opt for Kreeft's longer edition as a more worthwhile investment. It has everything except Q48 from Ethics, which only runs 2 pages. You'll get a much fuller appreciation of Aquinas and his philosophical ideals.

[J. Alfred · Rating 3 out of 5]

I appreciate St. Thomas both for his faith and for his smarts (I appreciate the same things about Peter Kreeft, the editor!). This is some excellent, if difficult, stuff to meditate over, especially the section on the summum bonum-- the greatest good (which turns out to be God). I freely admit, however, that even this little book is WAY over my head. If I remember correctly, however, Chesterton said that Luther himself wouldn't even make a dot in Aquinas' labrinthine intellect. So I don't mind being outmatched too much.

[J. Wootton · Rating 2 out of 5]

Aquinas' Summa Theologica is a masterwork of philosophy, but it's not clear to me whom Kreeft's excerpt-of-excerpt is meant to serve. I agree with Pheonix on this one: get Kreeft's Summa of the Summa instead. Or go directly for Aquinas: the Summa Theologica is available online for free, in some cases with excellently annotated hypertexts to help readers track interrelated ideas.

[Manuel · Rating 3 out of 5]

I don't know how to rate this book exactly. Should I rate Peter Kreeft or Thomas Aquinas? At the beginning of this book, Kreeft states that the Summa was meant to be a reference book, like a dictionary or encyclopedia. After reading "A Shorter Summa", and trying very hard at times not to fall asleep, I have to agree 100%. It certainly doesn't read like anything we are used to in modern philosophy texts. The language can be very terse and abstruse, and the debate format can become tiresome after a while. There are some virtues in this Thomistic style of starting off with questions, followed by objections, an answer, and finally a reply to each of the objections, one of which is that you stay on point and another is that it is extremely orderly. But it comes at a cost. Because the overall plan is to provide a summa (i.e. a summary) of all known philosophy (and theology) at that time, the medieval author had to economize on words, sometimes to the point that the conclusion of an argument leaves you wanting more exposition because it is not clear or obvious at all. True, if an argument is left unclear at one point, Aquinas sometimes provides a reference to another part of the Summa where that point is further developed, which will either satisfy you, send you to another part of the Summa, or leave you still wanting more exposition. There's something to be said for the modern style of philosophy, which in the best case is presented as a conversation, an exploration, in a way that is more congenial to how we work things out in our minds. Kreeft's idea of giving us a small (very small!) taste of what the Summa is like, with copious footnotes, cannot be faulted too much, for one always wants the original author to speak for himself. But the Summa is a special case, I think, and it only works as the full text, not as a sampler like "A Shorter Summa". If the idea is just to give the reader an idea of Aquinas' genius, then a few articles would have sufficed, filling (it's true) only a handful of pages. I would come back to this book in the future, but only to consult a few articles for reference, because a pleasant reading it is not.

[Rita · Rating 4 out of 5]

I am struggling with my Philosophy of God and Man class. Don't know if it's because I've never studied philosophy or I'm expecting to understand way more than required for this level. So I'm reading this book to get more background on what we're studying. It really helps

[Samuel Kropp · Rating 5 out of 5]

Helpful. The glossary of terms and the author forcing you to read them before continuing was well-thought and I found it helpful. A couple points were a bit slow but that’s just Thomas’s fault. I thought the epistemology section could have used some more footnotes to walk through the argument since I found it very dense at points. The diagram Kreeft provides near the end of the section was illuminating, wish it were earlier in the section. The ethics section was a nice relief on the brain after that.

Overall, very helpful. I imagine this will be very useful background knowledge to have going into other scholastic writers and authors.

[Lukas Stock · Rating 3 out of 5]

By making such a short abridgment Kreeft makes the Summa accessible to all. It’s a wonderful idea. The explanatory footnotes are generally good, but ultimately a secondary source is still probably desirable, especially for those lacking classical philosophical exposure.

[Chad Veal]

Don’t worry I’m still not catholic

[Dean Landers · Rating 5 out of 5]

Aquinas is the philosopher we need for this moment in history. He does more than address thorny questions with a bracing honesty that gives opposing views their full due - he teaches us to think. Kreeft's wonderful footnotes enrich rather than distract. He eases the reader into the mind of this medieval philosopher such that by the end I feel ready to tackle The Summa of the Summa..

[Luke · Rating 5 out of 5]

Concise and helpful. Thomas is much easier to read than the Thomists.

[Ted Martin · Rating 4 out of 5]

I had to read several sentences 5 times in order to understand them. The Epistemology and Psychology chapter especially. I can't imagine what the whole must be like. Peter Kreeft does a good job of bringing out the most famous points of Thomas d'Aquin. This should be a must-read for Protestants as well :)

In any case, how beautifully logical and rational Thomas makes faith to be.

[uncatastrophe · Rating 4 out of 5]

st thomas aquinas when i go back in time and show him object oriented programming

[Drew · Rating 5 out of 5]

Sort of like Barth’s Dogmatics in Outline but for Aquinas. Kreeft’s notes are both very helpful and often quite funny.

[Linda · Rating 5 out of 5]

“God is not American.” This along with other great statements and comparisons from the author made this book super helpful in understanding St. Thomas Aquinas’ philosophical views.

[Scott · Rating 4 out of 5]

Quite helpful as an introduction to the thought of Thomas Aquinas. Sometimes I thought that Kreeft's notes had a little too much cheerleading for Thomas, but he also helped me to understand the patterns that characterized Thomas' thought as well as some of the technical vocabulary.

[Mark · Rating 4 out of 5]

I have been putting off reading two saints' works, St. Thomas Aquinas and St. John of the Cross. The reputation of both precede them. I should not have been worried about Aquinas, except for maybe for the sheer volume.[return][return]This book, more edited than written by Kreeft, is a marvelous introduction and uses Aquinas's own words in anthology form from a more direct and literal translation than some others books. Kreeft included copious amounts of footnotes that are a great aid in understanding the concepts presented, although I found Aquinas in his own words fairly understandable as is.[return][return]This book collects the essential passages of Aquinas' great work and thus much is left out. (Aquinas wrote a Summa of the Summa, cutting it down from 3000 pages to 500. This one pairs it down even further, to under 200 pages.) My appetite has been wetted by this book for more Aquinas.

[booklady]

Have a new guide to St. Thomas which may help me to get into this... I've always wanted to read and learn about St. Thomas and this book was better than many I've tried but even so I had some difficulties.

I'm putting it on a new shelf, called "OPEN BOOK". I have a small number of books set aside that I'm not actively reading but when the time is right, there is a Blue Moon, or all the stars align with Mars, then I will pull one of them down and honor it with my gracious presence. Lucky book! ;)

[Tom · Rating 4 out of 5]

Went through the 12 lecture course by Peter Kreeft, and included study guide. Written by him. Dry at times, but well worth the effort. I appreciated Kreefts explanations and illustrations. It was fairly easy for us non-theologians to understand.

[John · Rating 5 out of 5]

This summary of St. Aquinas' treatise is a rigorously logical but rewarding gem.

[John · Rating 5 out of 5]

Summa Theologica is a work that I've begun reading before, and I've read chunks of it, but it is big and systematic and structured - so it does not make that easy to get through. So, Peter Kreeft makes it easier by extracting the most important part into a shorter version, this being the shortest version. In addition, he adds a bunch of informative and necessary footnotes to guide the reader. Not all are needed tho but appreciated still.

These excerpts of the Summa are really the heart of the work of Thomas Aquinas and is a very good starting point to get under the skin of his thought. It makes you want to read more and wonder what Kreeft did not include. The book contains the usual suspects like the five proofs, but then also some uncharted territory id one has not wandered through there before.

It is almost like a collection of highlights that one would highlight if one reads the whole Summa, although too many parts are not included so there are lots of important things missing.

[Laurent Dv · Rating 4 out of 5]

Une petite suite d'extraits de la Somme théologique de Thomas d'Aquin. Kreeft a sélectionné les parties les plus pertinentes et les plus faciles à comprendre (sachant que la Somme fait des milliers de pages), ce qui donne son livre réduit de seulement de 162 pages (et en gros caractères) ! Il est bien évidemment impossible d'inclure tous les sujets traités dans ce résumé, mais ça donne déjà un bon aperçu des idées de Thomas.

On trouve une introduction qui explique la pertinence de Thomas d'Aquin à notre époque (après tout, pourquoi lire un philosophe si vieux ?), un lexique avec la définition de tous les mots importants qu'il utilise et des commentaires en notes de bas de page qui aident beaucoup à comprendre le texte original. Seul point faible, il restait certaines parties que je n'ai pas bien compris et pour lesquelles il n'y avait pas de commentaires.

[Luke Daghir · Rating 5 out of 5]

Other than directly reading St. Thomas Aquinas, this is the number one book I recommend to someone wanting to learn more about St. Thomas Aquinas' thought.

Here are my thoughts:

1. Kreeft does an exceptional job of presenting the entirety of the Summa through the backbone of Aquinas' thought presented in this book.

2. This a great walk-through the Summa.

3. The footnotes are very helpful.

4. Kreeft's introduction is incredibly helpful as well.

5. This is a read that can be read cover to cover or over time by reading the short chapters (questions) one at a time.

[Evan Leister · Rating 3 out of 5]

As someone brand new to Aquinas this is a great intro. I liked the idea of reading through the actual work itself in summary form rather than someone else's commentary on it. However this didn't sell me on why I need to care about Aquinas. That is not meant to be a slight on Aquinas or any of those who find him valuable. I'm sure there's a compelling reason to read his work, but I just don't think I got that from this book and I'm still holding out for the reason to actually take the plunge into his work.

[Curby Graham · Rating 5 out of 5]

This book is a shortened version of Kreeft's earlier work A Summa of the Summa. Which is of course a condensed version of Aquinas' Summa. So from 3000 pages to 500 pages down to 160 pages. Kreeft takes only what he considers absolutely essential from Aquinas and adds a fair amount of notes and commentary. It is a very good way to introduce someone to Aquinas and makes a good companion to GK Chesterton's biography of the Doctor.

[Noah Calcagno · Rating 5 out of 5]

Thomas Aquinas deserves every iota of his reputation. He is one of the best philosophers and theologians of all time, and reading a paragraph of his work can be more helpful and encouraging than an entire volume of someone else’s.

A truly brilliant mind that certainly left its mark on Christianity and Western thought.

Peter Kreeft, the editor, also did an excellent job of selecting passages that highlight some of Aquinas’ most central thoughts.

[Daniel Alva · Rating 3 out of 5]

Epilogue to A Shorter Summa

I found this collection of passages intentional and easy -- generally. As with Socratic Logic what might be taken by the non-believer as the opinions of an erudite yet senile professor I find as refreshing, wise, and fortifying.

The segment about the Five Ways and happiness (although he notes this English word for 'felicitas' is misleading) offers a gentle introductory text for the but recently illuminated intellect.