Summa Theologica

Overview

The Summa is not a book you read from the beginning. It is a reference work with a shape, and knowing the shape is most of what a first-time reader needs.

Its unit is the article, and there are roughly three thousand of them. Each article is one to three pages and follows a fixed form. A question is posed so that it can be answered yes or no: whether God exists, whether it is lawful to kill, whether a human law binds the conscience. Then come the objections, introduced by a phrase meaning “it seems that”, stating the strongest case for the answer Aquinas will reject. Then a counterweight from Scripture or a Father, introduced by “on the contrary”. Then Aquinas’ own answer, which begins “I answer that” and is usually the shortest part. Then a reply to each objection individually.

This machinery repays a little practice. The objections are not straw men; they are frequently better stated than in the authors who held them, and there are articles where the objections are more memorable than the reply. Learning to read the form means learning to read the objections first, then the answer, then the replies, which is the order in which the argument actually moves.

Articles are grouped into questions, questions into treatises, treatises into three parts. The Second Part is so long that it is conventionally split in two, so citations run First Part, First Part of the Second Part, Second Part of the Second Part, and Third Part, abbreviated I, I-II, II-II and III. A reference like II-II q. 64 a. 7 means Second Part, second section, question 64, article 7.

The argument

Aquinas states his purpose in a prologue: existing textbooks repeat themselves, follow the accidents of commentary rather than the order of the subject, and confuse beginners. He proposes to teach in the order things stand in themselves, which for him means starting from God, moving out to creation and the return of rational creatures to God, and ending with Christ as the means of that return.

The First Part opens by asking whether theology is a science at all and whether it may use philosophical argument. Then question 2 asks whether God exists and gives the Five Ways, arguing from motion, from efficient causation, from the contingent to the necessary, from degrees of perfection, and from the ordering of things that lack intelligence. Each concludes in a single clause identifying the result with God, and none claims to show more. Questions 3 to 26 then proceed mostly negatively, establishing that God is not a body, not composite, not changeable, and that our words for God work by analogy rather than by literal description. The rest of the First Part covers the Trinity, creation, angels, the six days, and human nature, including a detailed account of soul and body in which the soul is the form of the body rather than a separate thing lodged inside it.

The Second Part is the moral philosophy and the section most likely to be assigned. I-II begins with happiness, argues that no created good can satisfy the human appetite for good as such, then works through voluntary action, the passions, habits, virtues and vices, and arrives at the Treatise on Law in questions 90 to 108. There Aquinas defines law, distinguishes eternal, natural, human and divine law, and argues that human law derives its force from natural law and loses that force where it contradicts it. Questions 109 to 114 treat grace. II-II is a vast catalogue of the individual virtues, faith, hope, charity, prudence, justice, fortitude and temperance, with the questions on justice taking in war, killing, theft, property and lying.

The Third Part treats the Incarnation and the sacraments. Aquinas stopped writing in December 1273, having said that everything he had written seemed to him like straw, and the work was completed by others from his earlier writings in a section called the Supplement.

How to read it

Do not start at the beginning and grind forward. Choose the questions your course assigns and read them whole, including the objections and replies. Most programs assign some combination of the following: I q. 1 on the status of theology, I q. 2 on the Five Ways, I q. 12 and 13 on what can be known and said about God, I-II q. 1 to 5 on happiness, I-II q. 90 to 97 on law, and a selection from II-II on justice or war.

Read the objections first, before the answer. Aquinas designed the form so that you would hold the opposing case in mind, and skipping to “I answer that” makes the text look more dogmatic than it is.

Learn the citation system early. It saves hours, and it is how everyone else discusses the work.

Two misreadings to avoid. The Five Ways are not offered as knockdown proofs of the Christian God, and Aquinas says almost immediately afterward that we do not know what God is. And natural law in the Summa is not a list of rules read off from nature; it is the claim that practical reason has starting points as theoretical reason does, and that the first of them is that good is to be done and pursued.

The Dominican translation is free, complete and slightly archaic. Use it for quoting. Use the Cambridge or Hackett volumes if you would rather read modern English for the sections you have been set.

Questions it raises

• The Five Ways each end by identifying a conclusion with God. Is that identification argued for, or assumed?
• If we cannot say what God is, in what sense do our words about God mean anything at all?
• Aquinas says an unjust law is not a law. Does that clarify our obligations or evade them?
• Can Aristotle’s account of the virtues survive being placed under a supernatural end it knows nothing about?
• The form of the article gives the opposition a fair hearing. Does that make the work more open than its reputation, or is the outcome fixed in advance?
• Aquinas calls his own writing straw at the end. What would that mean for the status of the whole project?