Is the Summa Theologica worth reading?

Yes. The Summa is one of the clearest books of theology ever written, and Aquinas wrote it, in his own words, "for the instruction of beginners". It is not meant to be read cover to cover. Read it one article at a time, starting with the objections, and pick questions you already care about. A single article takes ten minutes.

Why it is worth the effort

• It is shorter in each step than it looks. The whole is vast. Each article is a page or two, with the same five-part shape every time.
• It argues with its opponents fairly. Every article begins with the best case against Aquinas's own answer. You learn how to think about a question, not only what to think.
• It is the reference point. Catholic moral theology, natural law, just war, the soul, the virtues: most later discussion starts from, or argues with, the Summa.
• It is free and in English. The 1920 translation by the Fathers of the English Dominican Province is online at newadvent.org.

Why people find it hard

• They start at the beginning and stop at question 1. The opening question on the nature of sacred doctrine is one of the more technical in the book.
• They skip the objections. Aquinas writes his answer to meet them. Without them, the answer reads as a list of assertions.
• The vocabulary is technical. Act and potency, form and matter, essence and existence. These are learnable, and the Summa uses them consistently.
• They read it alone. It was written for students with a teacher.

How to read one article

Every article has the same parts:

1. The question, as "whether": Whether every lie is a sin?
2. Objections: the case for the answer Aquinas will reject.
3. On the contrary (sed contra): an authority pointing the other way.
4. I answer that (respondeo): Aquinas's own argument.
5. Replies to each objection, usually by drawing a distinction.

Read the objections, then guess the answer, then read the respondeo, then check how each reply deals with its objection. That habit is most of what a first course in scholastic method teaches.

Where to start

Pick a question you already have. Some good first articles:

• God's existence: First Part, question 2, article 3, the Five Ways.
• The soul: First Part, question 75, article 2.
• Natural law: First Part of the Second Part, question 94, article 2.
• War: Second Part of the Second Part, question 40, article 1.
• Lying: Second Part of the Second Part, question 110, article 3.

Our explainer pages read each of these in order, objections first. Start with the Five Ways.

How the Summa is organised

• First Part (Prima Pars): God, creation, angels, man.
• First Part of the Second Part (Prima Secundae): the human act, happiness, passions, habits, virtues and vices in general, law, grace.
• Second Part of the Second Part (Secunda Secundae): the virtues one by one, from faith, hope and charity to prudence, justice, fortitude and temperance.
• Third Part (Tertia Pars): Christ and the sacraments.
• Supplement: completed after Aquinas's death from his earlier writings, because he never finished the Third Part.

Is it finished?

No. Aquinas stopped writing in late 1273, part way through the Third Part, and died in March 1274. The traditional account is that after an experience at Mass he told his companion that everything he had written seemed to him like straw. The Supplement was put together afterwards by others.

Theologica or Theologiae?

Both titles are used. Summa Theologiae ("summary of theology") is the form most scholars use today. Summa Theologica is the older and still common form, used by the Dominican translation.

How Aquinian can help

Aquinian Studio is a reasoning study after the method of Aquinas. It can be a study companion for the Summa: ask about a question or article in the language you think in, and Aquinian distinguishes the terms, orders the authorities, and can put the reading into the form of a Disputation or a Lecture. Investigate takes a second pass at an answer, and is allowed to wound the first. It works in more than fifty modern languages, as well as Latin, Ancient Greek, Biblical Hebrew and Biblical Aramaic.

Aquinian is modelled on the method of St Thomas. It is not St Thomas, and it is not a priest. Named passages and editions should be checked against primary sources before formal use.

Read your first article with it: 150 free credits, no card.

FAQ

Is the Summa Theologica hard to read? Each article is short and follows the same pattern, so it is easier than its size suggests. It is hard if you start at question 1, skip the objections, or read it without help.

Can a beginner read the Summa? Yes. Aquinas wrote it for beginners. Start with a question you care about and read one article at a time.

Is the Summa Theologica available in English? Yes. The Dominican Fathers' translation (second edition, 1920) is freely available online at newadvent.org.