Why Anything Exists at All: Aquinas, Barron, and the Five Ways

A one-minute clip can name a topic, but it cannot carry a 13th-century argument. This episode uses it only as a doorway, then does the slower work.

The interpreter, and the thinker behind him

Robert Barron is a Catholic bishop — since 2022, bishop of the Diocese of Winona-Rochester in Minnesota — and the founder of Word on Fire Catholic Ministries. Long before short-form video, he wrote Thomas Aquinas: Spiritual Master (1996; reissued by Word on Fire Academic in 2022). Its central claim, in paraphrase, is that Aquinas is misread as only a cold system-builder: for Barron, logic and spiritual life in Aquinas belong together.

That explains why a clip about divine love leads back to arguments about causes. In the Summa Theologiae, Aquinas treats love, in part, as willing good to another, not merely feeling warmly toward them. God's love, on his account, is not a reaction to goodness already there, but a cause of goodness in things. Aquinas does not rest that claim on a slogan. He first asks whether God exists at all, and tries to answer with reason.

Thomas Aquinas (c. 1225–1274) was an Italian Dominican friar who studied under Albert the Great and taught in Paris and in Italy. He wrote commentaries on Aristotle and the unfinished Summa Theologiae. His usual method is a disciplined dispute: state a question, present the strongest objections, answer, then reply to each objection.

The Five Ways, in plain language

In Part I, Question 2, Article 3 of the Summa Theologiae, Aquinas sets out five short arguments, each starting from something observable and reasoning toward a first principle he identifies with God.

1. From change. Aquinas's word is usually translated as motion, but he means change broadly: something that could become hot becoming hot. A thing does not bring about that change in itself, in the same respect — its potential must be actualised by something already actual. Follow that chain, he argues, and it cannot trail off with no starting point, or nothing in the chain would have power to change anything else: a first changer, not itself changed by another.

2. From efficient causes. Things are brought about by other things. Nothing brings itself into being, because that would require it to exist before it existed. Remove a cause and its effects go with it, so a chain with no first cause would leave nothing to explain the causes operating now: a first efficient cause.

3. From contingency and necessity. Most things can exist or fail to exist: they are born, built, decay, and die. Aquinas calls such things contingent. If everything were only contingent, he reasons, there would have been a point at which nothing existed — and from nothing, nothing would have followed. So something must exist necessarily, not borrowing its existence from another.

4. From degrees. We say one thing is better, truer, or more noble than another. Aquinas argues that degrees make sense by reference to a maximum or standard, and that such a maximum is also a cause of that quality in lesser instances: a source of goodness, truth, and being.

5. From governance, or directedness. Non-intelligent things — plants, bodies, natural processes — regularly act in consistent, end-directed ways rather than randomly. Aquinas argues that such directedness in things lacking knowledge points to guidance by something with knowledge, as an arrow's flight points to an archer.

Two qualifications matter. First, the first three ways concern mainly a simultaneous, sustaining order of causes — often called a vertical series — not simply events stretching back in time; Aquinas did not think reason alone could settle whether the past is infinitely long. Second, each Way's end is a beginning, not a finish. A first mover or necessary being is, on Aquinas's own account, still far short of a being worthy of the name God. The Summa then spends many questions arguing what such a principle would have to be like.

The criticisms, stated fairly

David Hume pressed on causation itself. We observe events following one another regularly, Hume argued, but we do not directly observe a necessary connection that must hold. If causation is less certain than Aquinas assumes, extending it from things inside the world to the world as a whole becomes questionable. Hume also raised what later writers call a composition problem: even if every part of a collection has an explanation, it does not follow that the whole needs the same kind. And he asked why the universe could not be a brute fact, or why a first cause would have to be single.

Immanuel Kant pressed a different boundary. For Kant, cause and necessity work legitimately inside possible experience; applying them beyond experience, to a being outside time and space, exceeds the limits of knowledge. Kant also argued that the cosmological route depends on an absolutely necessary being whose existence is built into its concept — the move of the ontological argument, which he believed fails.

Specific ways attract specific doubts. Degrees do not obviously require an existing maximum: people can rank temperatures without a hottest possible thing existing. End-directed patterns in nature have, since Darwin, been given powerful explanations without conscious guidance in each case, making the fifth way often the most contested.

Defenders reply that several criticisms answer a different argument — for example, treating Aquinas's causes as a temporal line rather than a sustaining order. Whether that succeeds is the live debate. The fair conclusion is neither refutation nor settlement: a serious, contested attempt to reason from experience to a first principle.

How listeners can apply this

No one needs to reach Aquinas's conclusion to learn from his method. First, state the other side in its strongest form before answering it, as Aquinas does with his opening objections; a view beaten only in its weakest version has not been beaten. Second, separate the steps: much disagreement hides in an unnoticed jump, from parts to a whole, or from a first cause to a specific picture of God. Third, define key words early — change, cause, necessary, and love all do specialised work here. Fourth, practise the account of love this episode started from, in its most general sense: willing good to another person in a disagreement — wanting them to understand, and to be understood, rather than simply to lose. That is not a religious instruction. It is a discipline for arguing charitably about questions that matter.

Independent companion commentary. Not affiliated with or endorsed by Peterson Academy, and not a substitute for its courses.