The Target Of The Criticism

A cosmological argument starts from the existence or character of the world and asks what explains it. For this AQA point, the relevant version is Aquinas' Way 3: the argument from contingency and necessity.

In Aquinas' Way 3, the basic movement is:

The criticism lesson asks whether Hume and Russell show that this move fails. They do not mainly object to a tiny detail; they challenge the deeper assumption that the universe, or the total series of contingent things, must have the same kind of explanation as objects within the universe.

Hume: The Whole And Its Parts

Hume's Dialogues Concerning Natural Religion presents debate through characters rather than a simple authorial lecture. In Part IX, a version of the necessary-being argument is put forward, then criticised. For AQA purposes, the criticism is usually taught as Hume's criticism of the cosmological argument.

The key objection is about the move from explaining parts to explaining the whole.

Hume's criticism can be expressed as an argument chain:

1. We explain events and objects by finding their particular causes.
2. If each member of a series has an explanation, it is not obvious that the whole series needs a separate extra explanation.
3. Calling many parts "one whole" may be an act of the mind: we group them together, but that does not automatically create a new thing needing a new cause.
4. Therefore, the cosmological argument may commit a composition mistake: it assumes that what is true of each part must be true of the whole.

This matters because Aquinas wants to move from "contingent things need explanation" to "the total order of contingent things needs a necessary being". Hume presses the question: why must the total order be treated as one extra object needing a further cause?

Hume: Necessary Existence

Hume also challenges the idea that God's existence can be demonstrated as necessary. His criticism is not simply "God does not exist". It is more precise: he questions whether existence can be proved in the same way as a mathematical truth.

For Hume, if we can clearly conceive of something not existing, then its existence is not logically necessary in the strictest sense. We can conceive of the non-existence of anything we encounter or imagine, including the deity as described by natural theology. That makes "necessary existence" hard to use as a proof.

This creates two problems for Aquinas' Way 3:

This does not automatically show that belief in God is irrational. It does challenge the status of the argument as a proof. A student should therefore distinguish two judgements:

• AO1: Hume criticises the reasoning from contingent things to a necessary being.
• AO2: This may show that the cosmological argument is not a demonstrative proof, even if it still has value as a way of making belief in God intellectually serious.

Russell: The Universe As Brute Fact

Russell's criticism appears in Why I Am Not a Christian, where he discusses the First Cause argument. His target is close enough to the cosmological argument for AQA because both arguments ask whether the world must be explained by a first or necessary cause.

Russell's main challenge is sometimes called the brute-fact objection. A brute fact is something accepted as real without a deeper explanation. Russell argues that if the theist can stop the explanation chain at God, the non-theist can ask why the chain cannot stop at the universe instead.

Russell's criticism can be set out like this:

1. The cosmological argument says the world needs a cause or explanation.
2. It then says God does not need the same kind of cause or explanation.
3. Russell asks why this exemption is allowed for God but not for the world.
4. If something can be uncaused or unexplained, perhaps the universe itself can be that stopping point.
5. Therefore, the argument may special-plead for God rather than prove God.

Russell also questions whether the universe must have had a beginning. If there is no need to suppose the world began, the pressure to find a first cause is reduced. This is especially damaging to simple versions of the cosmological argument that say "everything has a cause", because that claim immediately raises the question of what caused God.

Comparing Hume And Russell

Hume and Russell are both critics of the cosmological argument, but they are not identical.

The overlap is important: both critics attack the demand for a final explanation. Hume does this by questioning the logic of whole-and-parts and necessary existence. Russell does it by saying the universe itself may be the final stopping point.

The difference is just as important. Hume is especially useful against Aquinas' move from contingent parts to a necessary whole-explanation. Russell is especially useful against any argument that says every explanation must lead beyond the world to God.

Possible Replies And Evaluation

Aquinas' defenders can reply that Hume and Russell are strongest against simple versions of the cosmological argument, not necessarily against every form of the argument from contingency.

The most important reply is that Aquinas is not simply saying "everything has a cause". If he were, Russell's question "what caused God?" would be immediately damaging. Aquinas' more careful claim is that contingent beings require explanation, while a necessary being does not receive existence from another in the same way. That means the argument is trying to distinguish two kinds of being, not apply one rule to everything and then make an exception for God.

There is also a reply to Hume. A defender of Aquinas can argue that explaining each part of a contingent series still may not explain why there is any contingent series at all. If every item in the series depends on another dependent item, the whole pattern may still look unexplained. On this view, asking "why is there something rather than nothing?" is not a confused extra question; it is the deepest question.

These replies do not make the argument automatically successful. They show what the evaluation should turn on:

Paragraph-Ready Judgement

A strong paragraph on this lesson should not merely list Hume and Russell. It should show how each criticism changes the force of Aquinas' argument.

AO1-to-AO2 bridge:

A basic paragraph says:

Hume and Russell criticise the cosmological argument, so Aquinas does not prove God. Hume says the universe does not need a cause and Russell says God would need a cause too. This makes the argument weak.

A stronger paragraph says:

Hume and Russell weaken the cosmological argument by attacking its explanatory demand. Hume argues that once the parts of a causal series are explained, it may be a mistake to demand a further cause of the whole, so Aquinas' move from contingent things to a necessary being may commit a composition error. Russell adds that if the theist can stop the explanation chain at God, the non-theist can ask why the universe itself cannot be treated as the stopping point. However, Aquinas' argument is not the crude claim that everything has a cause; it distinguishes contingent beings from a necessary being. Therefore, Hume and Russell are persuasive against the argument as a strict proof, but less decisive if the argument is used as rational support for faith.

Synoptic link: this lesson belongs with the wider AQA arguments-for-God cluster. It links most directly to Aquinas' Way 3, and more broadly to the AQA requirement to judge whether arguments for God's existence are proofs, supports for faith, or examples of the relationship between reason and faith.