Summa Theologica

What It Is

Aquinas worked on the Summa from 1265 until December 1273, when he stopped writing and never resumed; he died the following year, and the final section was assembled by others from his earlier work. It runs to some three thousand double-columned pages. He called it a textbook for beginners, which tells you what a thirteenth-century beginner was expected to survive.

The architecture is the thing. The work divides into parts, parts into questions, questions into articles, and every article has the same shape: a question is posed, then a series of objections make the case against Aquinas as forcefully as he can make it, then a brief counter-authority, then his own answer, then a reply to each objection in turn. Nothing is asserted until it has been attacked.

The objections are often better than what most people can produce against him today. He wrote them himself.

Why It Matters

Aristotle had just arrived in the Latin West, carried in by Arabic and Jewish commentators — Averroes, Avicenna, Maimonides — and to many churchmen he looked like a catastrophe: a complete account of the world with no revelation in it and no need for any. Paris banned parts of him. Aquinas took the opposite view — reason and faith cannot contradict each other, because they have the same author — and spent his life showing what that costs and what it buys.

The result became the intellectual constitution of Catholicism and has been its official framework since 1879. Out of it come the Five Ways, the classical arguments for God's existence; and natural law, the theory that there are moral truths accessible to reason alone, which stands behind the modern language of human rights and most of the just war tradition.

But the reason to read Aquinas is the method. This is the most disciplined instrument for thinking ever constructed. He never caricatures an opponent, never wins by volume, and never advances a claim without first putting the best case against it. Read fifty articles and your own arguing improves. That is worth more than any doctrine in the book.

Before You Read

Do not read it whole. Nobody does, and pretending otherwise is how people end up owning five volumes they never open.

Read it in articles. Each is two or three pages, self-contained, and can be finished over a coffee. Start with the Prima Pars, Question 2, where the Five Ways appear; the treatise on law (First Part of the Second Part, Questions 90 to 97), the foundation of natural law theory; or the treatise on happiness that opens the same part.

The vocabulary is Aristotle's — act and potency, essence and existence, form and matter — and it is technical. A glossary is not optional. The style takes an hour to get used to, and then becomes a pleasure, because you always know exactly where you are.

Which Translation to Read

• The Fathers of the English Dominican Province (Christian Classics, five volumes; translated 1911 to 1925, largely by Laurence Shapcote) — recommended. Complete, literal, consistent, and the version everybody quotes. Shapcote holds the technical vocabulary steady across the entire work, which matters more here than elegance, and the whole text is free online at New Advent. The cost: the English is stiff 1920s ecclesiastical prose, there is no help with historical context, and five hardbacks is a commitment. View on Amazon →
• The Blackfriars edition (61 volumes, Latin and English facing, 1964 to 1981; reissued by Cambridge University Press). The best scholarly apparatus in English: introductions, notes and appendices for each volume, with the Latin at your elbow. The cost: sixty-one volumes, quality that varies with the translator, and a price that puts it in libraries rather than houses.
• Timothy McDermott, Summa Theologiae: A Concise Translation (1989). One volume. McDermott dissolves the articles into continuous prose and cuts to roughly a seventh of the length. The cost: he throws away the form, and the form is the thing. He gives you Aquinas's conclusions, which were never the point.

Take the Dominicans. For a way in first, Peter Kreeft's Summa of the Summa (Ignatius, 1990) prints the philosophical passages with footnotes written for readers meeting scholastic argument for the first time.

Getting the Most From This Book

Read the objections first and try to answer them yourself before you look at what he says. That is how the book was designed to be used, and it is the difference between reading Aquinas and being trained by him.

One article a day for a year will take you further than a heroic month.

Do not start at Question 1. And do not come only for the Five Ways: they occupy about two pages out of three thousand, they are compressed to the point of obscurity, and they are not what the book is for.

Read Aquinas slowly and he is astonishingly clear. Read him quickly and he is impenetrable. He is one of the few writers where the fault, when you cannot follow him, is almost always yours.