3.3.2 - Cosmological arguments

The Cosmological Question

Cosmological arguments start from a feature of the cosmos: change, causation, beginning, contingency or dependence. They then ask whether that feature can be fully explained from within the cosmos itself.

The guiding question is:

Why is there a changing, caused, contingent universe at all?

That question is not yet the same as "Which religion is true?" or "What is God like?" Cosmological arguments usually move in two stages:

The first stage is normally the easier one to reconstruct. The second stage is more delicate, because a critic may accept that the argument reaches some first cause but deny that it reaches the God of classical theism. That issue is a major theme of the next lesson.

For this lesson, use these terms carefully:

The AQA specification asks students to pay attention to the logical form of arguments and the strength of their conclusions. So do not treat all cosmological arguments as one vague "first cause" argument. Each begins from a different explanatory pressure.

Kalam Temporal Causation

The Kalam argument is an argument from temporal causation. It asks what explains the universe's beginning to exist.

The core idea is simple: things that begin to exist do not just pop into existence without any causal explanation. If the universe began to exist, then the universe too needs a cause.

Claim at issue: The universe has a cause of its existence.

1. P1: Everything that begins to exist has a cause of its existence.
2. P2: The universe began to exist.
3. Therefore, C1: The universe has a cause of its existence.
4. P3: The universe includes physical time, space and matter.
5. Therefore, C2: The cause of the universe is not an ordinary physical cause within the universe.
6. Further theistic conclusion: The cause is best understood as a creator, which the theist identifies with God.

Hidden assumption: Causation can apply to the beginning of the universe, even though ordinary causes occur within the universe.
Inference type: Deductive if P1 and P2 are granted; a posteriori in its appeal to the universe beginning.
Main pressure point: Whether the causal principle and the claim that the universe began to exist are both justified.

The immediate conclusion is not yet "the God of classical theism exists". It is "the universe has a cause". A defender then argues that because the universe includes space, time and matter, the cause cannot simply be another event inside space and time. This is why the argument is often pushed toward a cause that is non-physical, not located within the universe, and powerful enough to explain the universe's existence.

There is a subtle timing issue. Kalam is a temporal argument because it reasons from the universe's beginning. But if time itself begins with the universe, the cause cannot be earlier in time in the ordinary way. The defender may therefore say that the cause is causally prior rather than temporally prior. That move matters, because it keeps the argument from asking for an event "before time" as if time were already running.

The main conclusion is therefore modest at first and stronger only after an extra step:

Detailed challenges about infinite series, the causal principle and whether the argument reaches God are taught in the next lesson. Here, the essential point is the argument's form: beginning plus causal principle gives a cause of the universe.

Aquinas First Way: Motion

Aquinas' First Way is the argument from motion. In Aquinas' Aristotelian vocabulary, motion means change, not only movement through space. A cold log becoming hot, a seed growing, or a body being moved are all cases where something moves from potentiality to actuality.

A log is potentially hot before it is actually hot. Fire, already actually hot, can make the log hot.

The First Way can be reconstructed like this:

Claim at issue: There must be a first unmoved mover.

1. P1: Some things are in motion or change.
2. P2: Whatever is moved from potentiality to actuality is moved by something actual.
3. P3: Nothing can be both potential and actual in the same respect at the same time.
4. Therefore, C1: Nothing can be the complete mover of itself in the same respect.
5. P4: A series of movers ordered here and now cannot regress infinitely, because later movers depend on prior movers for their moving power.
6. Therefore, C2: There must be a first mover that is not moved by another.
7. Further theistic conclusion: This first unmoved mover is what Aquinas calls God.

Hidden assumption: Dependent motion here and now requires a first source of actualising power.
Inference type: A posteriori and deductive if Aquinas' metaphysical premises are granted.
Main pressure point: Whether an essentially ordered series of movers really requires a first unmoved mover.

This is not mainly an argument about the first event long ago. Aquinas is concerned with a dependent order of actualisation. If a hand moves a stick and the stick moves a stone, the stick has no independent moving power in that respect; it moves only because it is being moved. Aquinas thinks a chain of this sort needs a first source that is not itself being actualised by another.

The conclusion is also precise. The First Way does not begin by assuming a fully described God. It concludes first to an unmoved mover: something that can actualise without itself being actualised by another. The further claim is that this is what everyone understands as God.

Aquinas Cause And Contingency

AQA also specifies Aquinas' Second and Third Ways. The Second Way is from efficient causation; the Third Way is from contingency.

An efficient cause is what brings something about or explains its existence in the order of causes. AQA calls the Second Way an argument from atemporal causation because the key dependence is not merely "earlier event causes later event". Aquinas is interested in an ordered causal structure where dependent causes need a first cause to have causal power at all.

Claim at issue: There must be a first efficient cause.

1. P1: In the world of experience, there is an order of efficient causes.
2. P2: Nothing can be the efficient cause of itself, because it would have to be prior to itself.
3. P3: In an ordered series of efficient causes, later causes depend on prior causes.
4. P4: Such a dependent causal order cannot regress infinitely, because without a first cause there would be no intermediate causes and no effects.
5. Therefore, C1: There must be a first efficient cause.
6. Further theistic conclusion: This first efficient cause is what is called God.

Hidden assumption: The relevant causal series is essentially ordered, so its members depend here and now on a first cause.
Inference type: A posteriori and deductive if the causal-order premises are granted.
Main pressure point: Whether the impossibility of infinite regress has been established.

The Third Way begins differently. It does not start from change or efficient causation, but from things that are generated and corrupted: things that come into being and pass away. Such things are possible to be and possible not to be, so Aquinas treats them as contingent.