Design argument: AQA A grade notes

AQA RS
Philosophy

AO1: Paley’s design qua purpose (watch)

William Paley asks us to imagine walking on a heath and seeing a rock.
The rock seems like it could have existed forever, since nothing about it suggests otherwise.
However, Paley claims we would think differently if we found a watch, because it has complexity enabling purpose.
Its purpose depends on the intricate structure of its parts and their precise arrangement in relation to each other.
Complexity alone is not enough to indicate design, since it can arise by chance.
For example, sand on a beach forms complex patterns but does not suggest design.
However, a sandcastle is different.
Its complex arrangement serves a purpose and is highly unlikely to occur by chance.
So it is more reasonable to infer that it was designed.
Paley concludes that we can infer design when something has purpose enabled by complexity.
This same property is found in nature.
The human eye, wings of birds, and fins of fish are composed of complex parts arranged to perform functions such as seeing, flying, and swimming.
So nature also shows complexity directed towards purpose.
So there must be a powerful, intelligent mind responsible for the world.
The argument is inductive and a posteriori, as it reasons from observation to a conclusion about God’s existence.

AO1: The status as a proof of the design argument

Design arguments are a posteriori, meaning they are based on experience.
For example, Paley’s argument begins from observing purpose and complexity in the world.
They are typically inductive, meaning their premises could be true while the conclusion is still false.
The premises provide evidence supporting the conclusion, but do not logically guarantee it.
Such arguments are associated with empiricism, the view that knowledge comes from experience.
Inductive reasoning therefore cannot deliver certainty.
Instead, it aims to show what we have most reason to believe given the available evidence.
Even if successful, the conclusion remains open to challenge.
This is because inductive arguments are defeasible, meaning new evidence could weaken or overturn them.
They can be criticised either by questioning their premises or by denying that the conclusion follows.
Design arguments often use analogical reasoning.
Where we cannot directly observe the cause of something, we compare it to something similar whose cause we do know.
This allows us to make a probabilistic inductive inference about the unseen cause.
Paley follows Aquinas in using a posteriori arguments as part of natural theology.
They are not intended to prove the Christian God with certainty.
Instead, they aim to show that the evidence points towards a designer.
This supports faith by increasing the probability that a specific religious belief is true.

AO2: The validity of analogy

Swinburne defends analogical reasoning as scientifically valid.
If we observe X and know it is similar to Y, whose cause we understand, it is rational to infer a similar cause.
Design arguments apply this to nature.
Objects in nature resemble artefacts or directed objects like watches or arrows.
So their cause is likely analogous, an intelligent mind.
This makes analogy a legitimate way of reasoning from known to unknown causes.

Counter

However, Hume argues that similar effects can have very different causes.
For example, dry ice and fire both produce smoke but arise from different causes.
So similarity does not justify inferring similar causes.
He also claims the analogy between artefacts and the universe is weak.
Artefacts are precise and mechanical, while the universe appears more organic and irregular.
So the comparison between watches and natural objects lacks sufficient similarity.

Evaluation

Hume’s critique fails against stronger interpretations of design arguments.
Many modern readings of Paley do not rely on analogy but on inference to the best explanation.
The watch is better seen as an illustration of how complexity and purpose typically arise from minds.
The argument instead focuses on the improbability of such features arising by chance.
This removes dependence on the strength of analogy.
The same applies to Aquinas’ 5th way, where the arrow illustrates goal-directedness rather than forming a strict comparison.
So Hume targets a weaker version of the argument.
Once reformulated probabilistically, design arguments avoid his criticism.

AO2: Hume’s critique: God not the only explanation

Hume argues that even if the design argument succeeds, it cannot prove the Christian God in particular.
Alternative explanations remain equally possible, such as multiple gods, a limited designer, or a god who later died.
There is no basis for preferring the Christian God over these options.
So the argument could be inductively cogent, yet still limited in scope.

Counter

Swinburne responds using Ockham’s razor, arguing that one God is a simpler explanation than many.
More importantly, Aquinas, Paley and Swinburne do not aim to prove the Christian God.
Their arguments belong to natural theology, using inductive a posteriori reasoning to support belief.
Evidence for a generic designer still increases the plausibility of a specific God.

Evaluation

Hume’s critique overreaches because it targets a stronger claim than design arguments intend to make.
Sophisticated defenders are careful to limit their conclusion to a generic designer.
Aquinas explicitly ends his argument by referring to “that thing we call God,” showing awareness of this limitation.
The argument is not meant to establish the full nature of God, but to provide a rational foundation for belief.
Faith then identifies this designer as the Christian God.
This division of labour between reason and faith is central to natural theology.
So Hume’s objection commits a straw man by assuming the argument aims to prove more than it does.
The limitation in scope is not a weakness, but an intended feature of the argument.

AO2: The epicurean hypothesis & the multiverse

David Hume’s epicurean hypothesis suggests that if the universe were eternal, random atomic combinations would eventually produce order by chance.
Given infinite time, even highly ordered structures would occur.
Hume does not claim this is true, only that it is possible.
This breaks the claim that order must come from God.
A modern example which makes the same point would be the multiverse, where many universes exist, making ordered ones unsurprising and explicible by chance.

Counter

However, Swinburne argues the multiverse is highly speculative and lacks direct evidence.
It may also be unfalsifiable, so it cannot function as a proper scientific explanation.
Swinburne concludes that science can describe laws but cannot explain why those laws exist at all.

Evaluation

Nonetheless, the multiverse remains a serious challenge to design arguments.
Even if it is speculative, it is not incoherent and is taken seriously in physics.
More importantly, Hume’s point does not depend on it being true, only possible.
If another explanation of order is available, the inference to God is no longer necessary.
This weakens the force of design arguments, which aim to show that God is the best explanation of the universe.
If the multiverse can explain order and fine-tuning just as well, then God is no longer especially supported by the evidence.
We have no reason to prefer the God hypothesis.
So the design argument loses its persuasive power.

AO1: Strength & weakness of design arguments

The validity of analogy
Strength: Analogical reasoning is valid as it’s used by scientists all the time, e.g., to understand an unknown disease from the analogy of its symptoms to a known one.
Weakness: Analogical reasoning in design arguments is weak, as similarities in effects do not always imply similar causes.
Darwinian evolution
Weakness: Darwinian evolution explains the appearance of design in organisms through natural selection, making a designer unnecessary.
Strength: Modern developments like fine-tuning shift the focus from animal biology to the order and purpose in the laws of the universe, which evolution cannot explain away.
Whether God is the only explanation
Weakness: The design argument cannot establish the Christian God, as multiple or limited designers remain equally possible explanations.
Strength: Natural theology underpins the design argument, which intentionally limits its conclusion to a generic designer, making belief in God more reasonable without overreaching its evidence.