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Course 14 · Lesson 2.4

What the ontological argument would show if it worked

10 minute read

Lessons in this course

Course 14 outline

Module 1: Arguments, Existence and Necessity

  1. What natural theology attempts and what it does not
  2. Necessary and contingent existence
  3. How to read and test an argument for God
  4. Philosophy of religion today: a map of the field

Module 2: The Ontological Argument

  1. Anselm and the argument of the Proslogion
  2. Gaunilo and the perfect island objection
  3. Kant: existence is not a real predicate
  4. What the ontological argument would show if it worked

Module 3: Cosmological Arguments

  1. Aquinas: the first three ways
  2. Infinite regress: what is the problem?
  3. Leibniz, the principle of sufficient reason and the argument from contingency
  4. Objections: the brute fact reply and the fallacy of composition

Module 4: The Kalam Cosmological Argument

  1. The kalam tradition: Philoponus, al-Ghazali and Bonaventure
  2. The modern argument: whatever begins to exist has a cause
  3. Did the universe begin? Philosophy and cosmology
  4. Objections and replies, and what follows about the cause

Module 5: Teleological and Fine-Tuning Arguments

  1. From Aquinas’s fifth way to Paley’s watch
  2. Hume and the Dialogues Concerning Natural Religion
  3. Darwin and the change in the design argument
  4. The fine-tuning argument: what is claimed and what is debated
  5. The multiverse and other replies

Module 6: The Moral Argument and Divine Hiddenness

  1. The moral argument: Kant, Lewis and contemporary forms
  2. The Euthyphro question and moral realism without God
  3. Evolution and moral knowledge
  4. The argument from divine hiddenness and Christian replies

Module 7: Contemporary Modal Arguments and Evaluation

  1. Possible worlds and modal logic in plain language
  2. Plantinga’s modal ontological argument
  3. Assessing the modal argument: what it needs and what it shows
  4. Weighing the arguments together, and what none of them prove

All courses

Program / Course 14: Arguments for the Existence of God / Lesson 2.4

What you will learn

  • State what the conclusion of the ontological argument is and is not.
  • Explain the gap between a greatest conceivable being and the God of Christian faith.
  • Describe the main reasons philosophers still find the argument puzzling.
  • Give a fair summary of the case for and against the argument.

The big idea

Suppose the ontological argument were fully successful. It would show that a being than which nothing greater can be thought exists. That is a large conclusion, but it is not the whole of Christian belief. It would not by itself say that this being became human, spoke through the prophets or saves sinners. Defenders say it establishes the foundation, and critics say that a foundation built from a definition is the very problem. A fair student holds both thoughts at once.

Key terms

Perfect being theology
A way of thinking about God which begins from the idea of a most perfect being and works out what such a being must be like.
Divine attributes
The qualities traditionally ascribed to God, such as knowing everything, having all power, being good and being eternal.
Possibility premise
In modern forms of the argument, the claim that a maximally great being is at least possible.
Burden of proof
The responsibility of the party making a claim to give reasons for it.
Natural theology versus revelation
The distinction between what reason may establish about God and what is learned only from God’s self-disclosure.
Epistemic
Having to do with knowledge and how a person comes to know or justify a belief.

Background

The ontological argument is unusual among arguments for God because it asks for no observation of the world. It also has a special puzzle attached to it: even philosophers who reject it often find it hard to say exactly why it fails. Bertrand Russell, a skeptic, recalled that as a young man he suddenly saw the argument was sound while walking in Trinity Lane in Cambridge, and later changed his mind. The story is often retold to show how persuasive and how treacherous the argument can feel.

Whether the argument works or not, it is useful to be clear about the scope of its conclusion. Anselm believed that his conclusion could be developed: from the idea of a greatest being he went on to argue that God is just, merciful, all-powerful and not made of parts. In the Proslogion these follow in later chapters. Whether these steps succeed is a separate question from whether chapter 2 does.

Step-by-step explanation

Step 1: Suppose the argument works

If it works, there exists a being such that nothing greater can be conceived. Anselm and his followers hold that such a being would have the attributes traditionally given to God: knowledge, power, goodness, and eternity. This approach is called perfect being theology, and it is used by many philosophers, believing and not, to explore what the concept of God contains.

Step 2: Notice what is not yet shown

The conclusion does not say that this being is Trinitarian, that it is personal in the way Christians mean, or that it has acted in history. Nor does it say that the being is the God of Israel. Those claims rest on revelation. Aquinas, Anselm and all major Christian thinkers say that reason prepares for faith but does not replace it.

A non-Christian theist, such as a Jew or a Muslim, can accept the conclusion and reject Christian doctrine. This is a fact that defenders of the argument do not deny.

Step 3: Understand why the argument still puzzles

Many people feel that the argument must contain a mistake, because it seems impossible to learn about the real world from a definition. Yet the mistake has been hard to locate. Some say it is in the idea that existence makes a thing greater. Some say it is in the claim that the fool really grasps the phrase. Some say it is in assuming that a greatest conceivable being is possible. Each diagnosis has defenders and critics.

A more modest view holds that the argument may be valid but shows only that if such a being is possible, then it exists. The question then becomes what supports the possibility.

Step 4: The case for the argument

Defenders say that the argument expresses a real insight: God, if there is a God, is not a thing that happens to exist but one whose nature is to exist. They add that the argument, in its modern forms, is logically valid, and the debate concerns its premises, which is where most good arguments are decided. They note that many people who think the argument fails agree that it is hard to show how.

Step 5: The case against

Critics say that a priori reasoning cannot decide what exists. They point to the parodies discussed earlier, to Kant’s point, and to the suspicion that the possibility premise is where the real work is hidden. They add that the argument convinces few people who are not already believers, and that arguments that persuade only those who already agree do little philosophical work.

A fair summary is that the argument is not accepted by most philosophers, is seriously defended by a minority, and has taught philosophy a good deal about existence, necessity and definition.

  1. If the argument worked, what would you be entitled to say about God?
  2. Does a successful argument of this kind support worship, or only belief?
  3. Where do you think the argument is most likely to go wrong?
  4. Why might even critics find the argument fascinating?
  5. What is the difference between the argument being valid and its being persuasive?
  6. Would it matter to you if a Jewish or Muslim thinker accepted the argument?

Examples

Russell in Trinity Lane

Bertrand Russell wrote that in 1894, as a student, he suddenly believed the ontological argument was valid, and that he later rejected it. He used the story to illustrate how convincing it can seem. The account is from his own writing, and the date is approximate.

A Muslim philosopher’s use

Some Muslim philosophers, following Avicenna, argued from the idea of a necessary being. A Muslim theist may accept a conclusion of this kind and reject the Christian doctrines of the Incarnation and Trinity. It shows how far the conclusion is from the full Christian claim.

Faith and the argument

A pastor in a village church says that his belief did not come from an argument, and that he finds Anselm moving for a different reason: it shows him why God is not one more thing in the world. (A constructed example.)

Different perspectives

Catholic

Catholic teaching holds that God’s existence can be known by reason, but the Church has not endorsed the ontological argument as such. Aquinas rejected it and Catholic philosophers remain divided. All agree that the result would fall short of the doctrine of the Trinity and the Incarnation.

Orthodox

Orthodox theology holds that God is known in worship and ascetic life, and that no argument can convey the knowledge of God. The ontological argument is thus rarely used, and when it is, it is regarded as a pointer, not as a ground.

Protestant

Protestants range from Barth, who read Anselm as theology inside faith, to Plantinga, who judged that the modal form shows belief to be rational but does not prove it to an unbeliever. Many Protestant evangelicals regard the argument as interesting but weaker than others.

Jewish and Muslim views

Jewish and Muslim philosophers have used arguments from necessary being. Maimonides, for example, argued for a necessary being in a form close to the cosmological argument. Both traditions hold that God is one, so the conclusion is compatible with their theology.

Skeptical views

Skeptics argue that the argument shows only that people can define things in clever ways. Some, like Oppy, have written detailed studies concluding that the argument fails to give a good reason to believe, while allowing that its flaw is not simple to state.

Why it matters

Because the ontological argument is so unlike others, studying what it would show teaches a lesson that applies to every argument in the course: the gap between a philosophical conclusion and a living faith. It also trains a reader to resist two errors, dismissing the argument because it is odd and accepting it because it is clever.

Common misunderstandings

Misunderstanding: If the argument worked, Christianity would be proved.

Correction: It would at most show that a greatest conceivable being exists. The specific claims of Christianity would remain to be examined.

Misunderstanding: Philosophers all agree that the argument has an obvious flaw.

Correction: There are many proposed diagnoses and no consensus about which, if any, is decisive.

Misunderstanding: Only Christians have taken the argument seriously.

Correction: Philosophers of many views, including secular ones, have treated it as a serious puzzle, and Muslim and Jewish thinkers used related arguments.

Misunderstanding: The argument is a sermon in disguise.

Correction: Its modern forms are stated with the tools of formal logic and are discussed by philosophers of all views.

Knowledge check

What would the ontological argument show if it worked?

It would show that a being than which nothing greater can be conceived exists. That is the God of philosophers, possibly with attributes such as power, knowledge and goodness. It would not by itself establish the Trinity, the Incarnation or the claims of any particular religion. Those depend on revelation and further evidence.

Why does the argument continue to puzzle philosophers?

It seems impossible to learn about reality from a definition, yet critics have not agreed on exactly where it goes wrong. Different diagnoses locate the error in the claim that existence makes a thing greater, in the grasp of the phrase, or in the possibility of a maximal being. No one answer has convinced everyone.

What does the possibility premise do in modern versions?

Modern modal arguments claim that if it is possible that a maximally great being exists, then it exists. The key premise is therefore that such a being is possible. Critics say that this is as hard to establish as the conclusion, and defenders say that it is at least reasonable to accept and not obviously false.

Why can a Jewish or Muslim theist accept the conclusion?

The conclusion is a being of supreme greatness who is one and necessary. This agrees with their own teaching about God. What they reject is the Christian doctrine that God is three persons and became human. The argument therefore cannot decide between these religions, only about the existence of a supreme being.

Think it through

  1. Does a conclusion that is smaller than the Christian message still matter to a believer?
  2. Is it a weakness or a strength that people struggle to name the flaw?
  3. What would persuade you that the possibility premise is true or false?
  4. How should a student treat an argument they cannot refute but do not believe?

Independent assignment

A fair verdict

In your own notebook, write 350 to 500 words. Write a balanced summary of the ontological argument in three paragraphs: what it claims, the strongest objection, and the strongest reply. Then write a fourth paragraph saying what the argument would show if it worked, and what it would leave unanswered. Do not send this to anyone.

Further study