Cosmological argument: AQA A* grade notes

AQA RS
Philosophy

AO1: Aquinas’ third way

Aquinas’ Third Way is part of his broader project in the Summa Theologiae, where he aims to show that belief in God can be grounded in reason as well as revelation.
It draws on the modal distinction between contingent and necessary beings.
P1. We observe that there are contingent beings (things that can possibly not exist).
P2. If it is possible for something to not exist, then there is some time in which it doesn’t exist.
C1. If everything were contingent, then at one time nothing existed.
P3. If nothing once existed, nothing could begin to exist, so nothing would exist now.
C2. So, there must be something that is not contingent, “having of itself its own necessity … That thing we call God.”
Aquinas’ focus is not temporal beginnings but ontological dependence.
Contingent beings require an explanation for why they exist rather than not.
He distinguishes between beings that are necessary through another (they must exist, but their necessity is caused or derived) and necessary through itself (their existence is self-explanatory).
If a being is necessary through another, its necessity is not ultimate as it still depends on something else for why it exists.
So, even an infinite regress of such beings would consist entirely of derivative necessity.
But derivative necessity cannot explain itself; it only passes the explanatory burden along.
Therefore, without a being whose necessity is self-grounded, there would be no ultimate explanation for why anything exists at all.
So the argument ultimately aims to establish a being whose necessity is self-explanatory, grounding all contingent existence.

AO1: The status as a proof of the cosmological argument Edexcel AQArs

Cosmological arguments are a posteriori, meaning based on experience.
E.g., Aquinas’ ways are based on observation of motion, causation and contingency in the world.
They are typically inductive, meaning their premises could be true yet their conclusion false.
Their premises provide supporting evidence, but do not logically guarantee the conclusion.
Such arguments are typically made by empiricists, who hold that knowledge comes from experience.
Inductive proofs therefore cannot establish conclusions with certainty.
If successful, they show what we currently have most reason to believe based on the available evidence.
They are ‘defeasible’, meaning further evidence could overturn or shift the balance of probability.
So, they can be contested by rejecting the premises or denying the conclusion follows.
Cosmological arguments often depend on an explanatory principle such as:
Leibniz’ Principle of Sufficient Reason: that everything has an explanation for its existence, even if we cannot know it.
Aquinas’ causal principle: that whatever is caused requires a cause.
Aquinas supports such principles a posteriori, since in experience we observe that things have causes or explanations, although he holds that once grasped they are understood as necessary.
Nonetheless, the argument remains inductive despite containing a supposedly necessary premise.
This is because the principle does not straightforwardly apply to a whole series of causes, and it does not by itself establish the existence of God.
Therefore, the move from the causal principle or PSR to God is not an analytic deduction, but involves further assumptions.
So the conclusion is not logically entailed, but probabilistically supported, making the argument inductive.

AO1: Strength & weakness of the cosmological argument AO2 summary

The fallacy of composition
Weakness: The fallacy of composition attacks the assumption that the universe as a whole requires an explanation just because its parts do.
Strength: Cosmological arguments start with what we observe and don’t even mention the universe as a whole, which avoids fallacious part to whole reasoning.
The im/possibility of an infinite regress
Strength: An infinite regress may lead to paradoxes regarding infinite library examples and traversing an infinite to get to the current moment.
Weakness: Scientific models and the lack of empirical evidence undermine claims that an infinite regress is impossible, weakening philosophical arguments against it.
The brute fact
Weakness: The possibility of brute facts suggests that not everything requires an explanation, challenging the principle of sufficient reason.
Strength: The consistent practice of seeking explanations in science and philosophy supports the idea that reality is intelligible and may have an ultimate explanation.
The Im/possibility of a necessary being
Weakness: The concept of a necessary being is criticised as logically incoherent, since anything that can be conceived to exist can also be conceived not to exist.
Strength: Cosmological arguments reference God’s necessity as metaphysical rather than logical, avoiding the ontological argument’s issue of thinking existence is a predicate.

AO2: Hume’s critique of the causal principle

Cosmological arguments assume every event has a cause (the causal principle).
Hume argues this can be coherently denied, so isn’t analytically true.
An uncaused event is not an inconceivable contradiction.
Swinburne argues a causal principle could instead be synthetic a posteriori.
Since, every event we experience has a cause, the evidence justifies the causal principle as an empirical generalisation.
Hume objects:
This assumes conditions observed in the universe are evidence about its ultimate origin.
The only valid evidence for the universe having a cause would be observing its creation.
So, there seems no logical nor evidential basis for the causal principle.

Counter

Aquinas’ sustaining causation avoids Hume’s critique.
We observe ‘secondary causes’, which do not contain their own independent causal power.
So, they must depend on another cause that does contain causal power, and this chain of dependence ultimately requires a primary (first) cause.
A secondary cause with no cause is an inconceivable contradiction.
So a causal principle based on sustaining causation could be analytically true.

Evaluation:

However, there is no reason to believe sustaining causation exists.
It is based on the metaphysical assumption that motion/causation is not explained only by prior causes, but requires an ongoing primary causal support.
The issue is, modern physics sees no basis or need for this idea.
Guth’s inflation theory claims the universe has zero total energy, requiring no energy to be created. Krauss says this shows how a universe can come from nothing.
This shows Hume took the right position. The universe’s origin could be a radically strange event.
The causation we observe could have no ultimate explanation. So it needn’t have been caused by a God.

AO2: The fallacy of composition

X being true of a thing’s parts doesn’t mean it’s true of the whole.
Russell: E.g., Just because every human has a mother, doesn’t mean the human race has a mother.
Parts of the universe have a cause, mover or contingent status.
But that doesn’t mean the whole universe has such an explanation.

Counter

Copleston counters: cosmological arguments don’t claim the whole has a cause because its parts do.
Edward Feser points out Aquinas doesn’t reference the whole universe, only things we observe.
Observed things require an explanation, so the series of contingent things requires an explanation.
Copleston: a series must either be necessary or have an external explanation.
A series of contingent objects, even if regressing infinitely, cannot be necessary.
So, it still needs an external explanation.
As Aristotle put it, we can still ask why an infinite series exists.

Evaluation

However, this commits the ‘reification’ fallacy: mistaking an abstract concept for a concrete thing.
A series is not a ‘thing’ needing its own explanation.
Hume illustrates a collection of contingent beings (20 particles).
Explaining each particle explains the whole collection.
Thinking the whole has its own further explanation is absurd.
This is because a collection is not a concrete thing over and above its parts.
Likewise, a series is not a thing but a mental collection of events, nothing over and above its parts.
So, only its parts need explanation.
In an infinite series, each part is fully explained by prior parts.
This fully explains the series.
Copleston’s insistence that the series must have its own explanation mistakes a series for a concrete thing like its parts.

AO2: The im/possibility of an infinite regress

Aquinas and Leibniz didn’t think an infinite regress could be disproven, so designed their arguments to be compatible with it.
They argue an infinite series of causation or contingency still requires explanation in a primary cause or necessary being.
Craig argues an actual infinite is metaphysically impossible though, which would strengthen the argument.
E.g., a library with an infinite number of books, half of which are green.
Half infinity is still infinity, so the green books are paradoxically both less than and equal to the total.
He also argues an infinite cannot be traversed, so we could not have reached the present if infinitely many moments had passed.

Counter

Hume argues there is no contradiction in an infinite regress.
Some theoretical models support this.
Cyclic models (e.g. ‘big crunch’) propose infinite cycles without a single infinite timeline.
This could avoid Craig’s issues about infinities existing, or needing traversing.
Inflation theory posits a quantum field generating universes.
This field could be necessary or a brute fact, and even outside of spacetime, making temporal causation inapplicable.
The notion of an ‘infinite regress’ may then not apply, since there is no temporal sequence.
So reality could have no beginning, while avoiding Craig’s paradoxes.

Evaluation:

Hume takes the right stance on the relationship between philosophy and science.
Scientific theories avoiding Craig’s paradoxes shows the weakness of philosophical speculation about physical concepts.
Einstein’s joke that time is ‘what clocks measure’ highlights how little we understand it scientifically.
The ‘time’ Craig analyses might bear little resemblance to the actual phenomenon.
Scientific developments have overturned past metaphysical intuitions (e.g. non-Euclidean space, quantum mechanics).
So Hume’s intuition stands: without empirical grounds, philosophical reasoning alone cannot establish that an infinite regress is impossible.

AO2: The Im/possibility of a necessary being

Hume argues that our imagination is only constrained by necessity when it comes to logical truths, e.g., we ‘have to’ think 1+1=2.
The idea of a necessary being is inconceivable.
This is because whatever we can imagine existing, we can imagine not existing.
So, we can have no idea of a being whose non-existence implies an inconceivable contradiction.
Russell concludes necessity is a property of propositions, not beings.
So, the proposition “God exists” cannot be necessary.

Counter

However, Copleston responds that this critique only targets the ontological argument.
Anselm argued God’s non-existence was an inconceivable contradiction.
But Cosmological arguments only argue that a necessary being is the metaphysically necessary explanation of reality.
If a contingent world exists, then a necessary being must exist as its sufficient explanation.
So, cosmological arguments rely on God’s existence being metaphysically necessary, not logically necessary.
Copleston accuses Russell of reducing metaphysics to logic, treating questions about being as if they were merely about language or propositions.

Evaluation

However, Hume advances an argument that undermines even these modern defences.
Even if we grant coherence to the idea of a metaphysically necessary being, it does not follow that this being must be God.
For all we know, the necessary being could simply be the universe itself, or some fundamental form of matter.
Hume’s point anticipates modern proposals in cosmology, such as the possibility of a non-spatio-temporal quantum field that generates universes, as suggested by inflationary theory.
Naturalistic explanations could therefore play the very role that Copleston assigns to a necessary being.
Cosmological arguments cannot give us a reason to believe the necessary being must be any sort of God.