AO1: Aquinas’ 5th way
- Aquinas’ 5th Way is an a posteriori argument based on observation.
- Natural beings do not behave chaotically but almost always act in a goal-directed way towards their good end.
- We see this in flowers turning towards the sun, birds flying south in winter, and the motion of planets.
- This regularity suggests behaviour is not due to chance.
- However, these beings are not sufficiently intelligent to direct themselves.
- They cannot understand or choose their goals.
- So there must be some intelligent being which directs them towards their ends.
- Aquinas illustrates this with the example of an archer and an arrow.
- An arrow moves towards a target, but only because it is directed by an archer.
- The arrow itself has no awareness of its purpose.
- So when we observe goal-directed behaviour, we infer an intelligent director.
- Similarly, natural objects must be directed by an intelligent mind.
- God directs them through natural laws, which govern their behaviour.
- Each being has a nature which inclines it towards its telos.
- So Aquinas concludes that the order of nature points to an intelligent designer, “that thing we call God”.
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.
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: Darwinian evolution vs design
- William Paley and Thomas Aquinas appeal to the complexity and purpose of organisms as evidence of design.
- However, Darwinian evolution by natural selection provides an alternative explanation.
- There is variation within species, and individuals better adapted to their environment are more likely to survive and reproduce.
- They pass on genes coding for advantageous traits, which become more common over time.
- This leads to increasing adaptation across generations.
- As a result, organisms appear designed for survival.
- In reality, these traits developed gradually through natural selection rather than intentional design.
- Features such as instincts and goal-directed behaviour can be explained this way.
- So what Aquinas described as a telos can instead be understood as the outcome of evolutionary processes.
- Richard Dawkins develops this critique in The Blind Watchmaker.
- Referring to Paley’s example of the eye, he argues that complex organs can evolve step by step over long periods.
- Each stage offers a small advantage, allowing gradual development of complexity.
- Dawkins concludes that there is a “watchmaker”, but it is blind, meaning natural selection rather than a conscious designer.
- So complexity and purpose can be explained through natural processes, making belief in a designer unnecessary.
AO2: Hume & Darwin on Design vs the problem of evil
- Charles Darwin argued that the cruelty of natural selection undermines belief in design.
- He pointed to cases like parasitic wasps, whose larvae consume hosts alive, as evidence against a benevolent designer.
- David Hume develops this into the evidential problem of evil.
- If the world were designed by a perfect God, unnecessary suffering could have been avoided.
- So natural evil counts as evidence against a perfect creator.
Counter:
- Religious philosophers attempt to respond with theodicies.
- These generally claim it is logically impossible for God to remove evil without also removing some greater good necessarily connected to evil.
- E.g., our deserved punishment for Augustine, free will for Plantinga or soul-making for Hick.
Evaluation:
- These responses fail to address the evidential force of natural evil.
- Suffering inflicted on innocent children and animals cannot plausibly be justified by free will or punishment.
- Hick’s soul-making defence claims that random suffering is necessary to preserve epistemic distance, but this is unfalsifiable and lacks empirical support.
- So while God’s existence may be logically consistent with evil, it cannot be inferred from the evidence.
- This directly undermines the aim of design arguments.
- Natural theologians like Thomas Aquinas and William Paley appeal to observation to support faith in a perfect God.
- But once all the evidence is considered, including suffering, the world appears imperfect.
- So the most reasonable inference is not to a perfect designer, but to an imperfect or limited cause.
AO2: Design arguments after Darwin
- F. R. Tennant and Swinburne develop design arguments beyond biology to the structure and intelligibility of the universe.
- Swinburne argues Aquinas’ focus on temporal order is stronger than Paley’s spatial order.
- Evolution may explain organisms, but not why laws of nature exist.
- The precise constants required for life suggest fine-tuning by a designer.
Counter
- This assumes the laws of nature could have been different.
- However, they may be metaphysically necessary rather than contingent.
- Physicists search for a unified theory that explains why the constants must be as they are.
- Just because we can imagine different laws does not mean they are really possible.
- So fine-tuning may not require explanation by God.
Evaluation
- The broader problem is that design arguments rely on gaps in scientific explanation.
- Even in their refined form, they risk becoming a God-of-the-gaps argument.
- Evolution showed that Paley’s appeal to complexity was misplaced, but more importantly, it revealed a deeper issue.
- Lack of explanation does not justify inferring God.
- This same mistake appears in fine-tuning arguments.
- Just because we cannot currently explain the laws of nature does not mean God is the best explanation.
- Future science may provide deeper explanations, such as necessary laws or unified theories.
- So the argument rests on temporary ignorance rather than strong evidence.
- This makes modern design arguments no more convincing than earlier versions.