Design argument


A posteriori. The design argument and cosmological arguments are a posteriori arguments, which means they are based on experience. The design argument is based on the observation of particular aspects of the universe which, it claims, have the appearance of design. The cosmological argument is based on observation of everything in the universe being contingent and therefore requiring a creator which is necessary. These observations form the premises of the design and cosmological arguments. On the basis of those observations, an inference is then made to the nature of the origin of the universe.

Inductive. These arguments are called inductive arguments, which means they have premises which give evidence for, and support to, a conclusion. The truth of the premises does not logically entail the conclusion. So, inductive arguments are those for which their premises could be true and yet their conclusion false. They give us reasons for accepting a conclusion, though cannot prove that the conclusion is certain. The best an inductive argument can achieve is to show that a conclusion is what we currently have most reason to believe based on our best attempt to understand the available evidence.

William Paley’s design argument

Design qua Purpose is Paley’s argument that the combination of complexity and purpose are best explained by a designer.

Paley illustrates this with the example of a watch. If you were walking on a heath and came across a watch, you couldn’t argue it had come about by chance nor been there forever because it has Complexity & Purpose. This must mean it had a designer – a watch maker. Paley then points out there are also things in the universe that are complex and have a purpose. He points out in particular the complexity of the Human eye which is arranged to fulfil the purpose of enabling us to see. He also points to the wings of a bird and fins of a fish which are examples of complexity fitted together to perform a purpose of flying and swimming.

“Every manifestation of design, which existed in the watch, exists in the works of nature.”

Since complexity and purpose in a watch tells us there must have been a watch making, similarly the complexity and purpose in the universe tells us that there must have been a universe maker: God.

Design qua Regularity is another type of design argument made by Paley which draws on the observation of the order found in Newtonian physics. Paley pointed to the rotations of planets in the solar system and how they obey the same universal laws as shown by Newton’s laws of motion and gravity. Paley argued that unless gravity consistently has the strength it does within a narrow boundary, then the planets would be unable to maintain their order and life on earth could not exist. Similarly, why is the universe regular and not chaotic? This could not have come about by chance.

David Hume’s critiques of the design argument

Hume’s evidential problem of evil

Hume aims to show that a posteriori observation of the world cannot provide a basis to conclude that a perfect God exists because the world contains imperfections like evil. Hume isn’t trying to prove that there is no designer, just that a posteriori evidence cannot be used to show that the designer must be the God of classical theism (omniscient, omnibenevolent, omnipotent).

‘I … allow, that the bad appearances, notwithstanding all my reasonings, may be compatible with such attributes as you suppose: But surely they can never prove these attributes’

Hume, as an empiricist, insists that we are only justified in believing what the evidence suggests. The evidence of an imperfect world, while logically compatible with a perfect God, can never justify belief in a perfect God.

Paley responds that even a broken watch must have a watch maker, and so too must it be with the universe.

Alternative response to Hume’s evidential problem of evil: theodicies.

Hume’s criticism of the use of analogy

Hume argues that it doesn’t follow from the similarity of two effects that they must have had similar causes. For example, the smoke produced by fire and dry ice is very similar, but their causes not similar. So, just because the effect of the universe and the effect of a a man-made thing like a house (Hume’s example) or a watch are like each other in that they both have complexity and purpose, it doesn’t follow that the cause of the universe must be like the cause of a house/watch i.e., a designer. Two effects which are alike (analogous) might in fact have very different causes.

Hume highlights this by pointing to our utter ignorance of the state of nature during the beginning of the universe:

“Can you claim to show any such similarity between the structure of a house and the generation of a universe? Have you ever seen nature in a situation that resembles the first arrangement of the elements ·at the beginning of the universe·?” – Hume.

Even if we could claim an analogy between natural things and man-made things, for all we know there may be no analogy between their origin.

Hume argues further that we can’t even claim analogy between artefacts and natural objects. Artifacts are mechanical, but the universe appears more organic.

Paley’s argument is arguably not based on an analogy. Modern philosophers tend to read Paley’s argument as not being based on an analogy between artefacts and the universe. His argument is that there is a property which requires a designer; the property of complexity and purpose – parts fitted together in a complex way to perform a purpose. When a complex of individually complex parts are fitted together in a meticulous way so as to achieve an overall function/purpose, it seems almost impossible for that to have come about by pure chance. A better explanation is a designing mind. Man-made things have this property but so too do natural things like the eye. Therefore, nature requires a designer because it has this property, not because of any analogy to man-made things. The watch is merely an illustration. We know the universe is designed because it has complexity and purpose.

Hume: the teleological argument is arguing from a unique case

Hume challenges the idea that we could possibly know that complexity and purpose must be caused by a designer in the case of the universe. He contends that inferring the existence of one thing from the existence of another thing requires experience of their constant conjunction. It follows that if we want to infer a designer from a thing, we need one of two options: either experience of that thing being made and its designer, or experience of similar things being made and their designer.

For example, to take Hume’s example of a house, justifiably inferring a designer requires either experience of that house being made by a designer, or experience of other houses being made by a designer. Yet, regarding the universe, we clearly do not have either such experience.

“But it is hard to see how this pattern of argument can be appropriate in our present case, where the objects we are considering don’t fall into sorts, but are single, individual, without parallel or specific resemblance.“ – Hume.

“To make this reasoning secure, we would need to have had experience of the origins of worlds” – Hume.

All we experience is one case – the universe itself, we do not experience the origin of the universe, nor any creator conjoined with it. This one case is a unique case because nor do we experience the origin of other universes, let alone creators conjoined with them.

So, we ultimately have no basis on which to infer the existence of a creator from our universe. Hume concludes that the origin of the universe, “exceeds all human reason and enquiry.” So, we lack the required experience to justify inferring the existence of a God from the nature of the universe through a posteriori reasoning. The only rational thing to do is suspend judgement and admit that we do not know why the world exists as it does.

“A very small part of this great system, during a very short time, is very imperfectly discovered to us; and do we thence pronounce decisively concerning the origin of the whole?” – Hume.

Hume’s argument doesn’t apply to the watch. Paley’s argument rests on the premise that we know a watch is designed by its complexity and purpose. Arguably a person could come across a watch and would know it was designed, even if they had never seen watching being made or even heard of how they were made. So, it looks like Paley is right that someone can know something is designed by its complexity and purpose, and that Hume is wrong to think that experience of the causal process that originated it is required to know whether it was designed.

Actually it does. However, Hume’s point is that even if someone got the correct idea that a thing is designed by observing its complexity and purpose, they actually don’t have justified knowledge. It’s possible for someone to get a correct idea through unjustified means. Paley could even be right that complexity and purpose is the feature of the watch that tempts us to the conclusion that it was designed, but that doesn’t justify the belief that the watch was designed. Even though the belief be true, it may be false for anything they know, because they lack justification. The only way to know a watch is designed is to see it being made.

Hume: God is not the only explanation

Hume argues that even if we had evidence of design in the universe, that would not support the claim that it was designed by the God of classical theism. It could have been made by a junior God, apprentice God – or even a God who died. There could be multiple designers – ‘a committee of Gods’. So, the design argument doesn’t even justify monotheism.

Swinburne claims that Hume’s points here are correct and that the design argument cannot prove that the designer has the attributes of the God of classical theism. Other arguments will be needed for that.

However, Swinburne thinks that Ockham’s razor can be used against some of Hume’s claims here. One God being responsible for the design of the universe is a simpler explanation than multiple. Swinburne also points to the uniformity of the laws of physics as suggesting a single designer.

Hume’s Epicurean hypothesis

Epicures was an ancient Greek philosopher who thought the universe was had existed infinitely and was composed of atoms. Hume pointed out that if Epicures was correct, then a chaotic random universe, given an infinite amount of time, will by complete chance occasionally assemble itself into an orderly one. The atoms will happen to collide in such a way that an orderly arrangement of them will come about. On an infinite time scale, if something can possibly happen then no matter how low the probability, it becomes 100% guaranteed to happen. Not just once, but an infinite number of times! For example if monkeys were randomly banging away on typewriters for an infinite amount of time, then they would produce the entire works of Shakespeare. Similarly, a chaotic universe of randomly moving and fluctuating objects will happen to coalesce into an orderly arrangement given an infinite time frame.

The current scientific view is that time began at the big bang, however. Therefore there has not been an infinite amount of time.

However, perhaps there were infinite universes before ours or an infinite number of universes (multiverse theory). Rather than a regular universe occurring by chance due to an infinite time-frame, instead it could be that a regular universe occurred by chance due to there being an infinite number of every type (regular and chaotic) of universe.

Swinburne’s response: however, there is very little evidence for the multiverse theory. Polkinghorne agrees and claims that the multiverse theory is a ‘bold speculation’, a ‘metaphysical guess’.

Darwin & modern design arguments

Darwin’s theory of evolution by the process of natural selection showed that order in nature was not necessarily evidence of purpose and design but could instead be explained by natural scientific means. This suggests that proponents of the design argument are wrong to think that apparently purposeful features of animals must have been created by a designer.

Paley identifies that cases where complexity serves a purpose are so unlikely to come about by chance that it is more reasonable to believe that they were designed.

However, evolution shows that there is a third option. There is genetic diversity within all species. Natural selection refers to the increased chance for members of a species more adapted to survival to pass on their genes. The result is increased prevalence of adaptive traits over time. This explains how incredibly complex organisms can come to exist through the process of evolution by natural selection. It’s not an organism coming about by random chance, but nor does it require a designer. So, design arguments are wrong to think that complexity is suggestive of purpose or design.

F. R. Tennent

Tennent made two main arguments which paved the way that most defenders of the design argument went in after Darwin. Tennant accepted the scientific evidence for evolution but argued that humans had features that evolution without God could not explain (aesthetic principle) and that for evolution itself to be possible presupposes an extraordinarily unlikely level of order (anthropic principle) which is better explained by a God than by chance.

Tennent’s aesthetic principle suggests that evolution could not have produced humans without God’s interference with evolution. How can Darwinian evolution explain our perception of beauty? It doesn’t give us a survival advantage, yet it evolved. Only God controlling evolution can explain this.

Dawkins’ criticism of Tennent: perception of beauty makes animals more attractive to their mate which results in more offspring, which is good for survival.

Defence of Tennent: sexual attractiveness doesn’t seem to be all there is to beauty, what about music, literature, nature.

Counter-defence: The evolution of the perception of beauty could simply be a biproduct of the evolution of intelligence

Tennent’s anthropic principle. Tennant points out that this universe being hospitable to living beings requires a “unique assembly of unique properties” on a “vast” scale, including “astronomical, thermal, chemical, and so on”. Our universe has to be orderly and the order must be of a particular kind in order for evolution to have been possible and thus for us to exist. This suggests that our planet has been specially designed for human life to be possible.

However, it started to become clear that although the conditions on earth were very precise, given how large the universe is and how many planets there are in it, we should expect there to be many earth like planets completely by chance. No special kind of explanation like design is necessary. In our galaxy alone there are 100 billion planets.

Swinburne’s design argument from temporal order/regularities of succession

This argument is also sometimes called the anthropic fine-tuning argument.

Swinburne’s argument does not rely on spatial order or regularities of co-presence. This refers to the order of objects in space. For example, Paley’s illustration of the human eye is a case of spatial order because the order involved refers to the complex arrangement of things in space.

Because of this, Paley’s argument is susceptible to critique by Hume and evolution.

Swinburne bases his design argument on temporal regularities, also called regularities of succession.

E.g., the element of carbon has the same properties now as it did 10 billion years ago. Hydrogen in our part of the universe behaves in exactly the same was as Hydrogen across the other side of the universe. There are only a few laws which sum up all of nature. Everything in the universe is composed of around 12 fundamental sub-atomic particles. All of this orderliness persists throughout time which makes it temporal order.

The important point about temporal order is that it depends on laws of nature/physics.

This all requires explanation, Swinburne argues. We should not expect such order to exist by chance.

  • Why are there laws of nature at all?
  • Why are the laws of nature uniform and unchanging?
  • Why do we have these laws, rather than other laws?
  • Why are the laws that exist so perfect for human existence, when so many others are possible?

Number 3 is sometimes called ‘fine tuning’. If the laws of our universe, such as the charge of the election, were a tiny degree greater or lesser, life could not exist at all.

Swinburne thinks it is unimaginably unlikely for all these things to happen exactly as they do by chance.

Swinburne then claims that science cannot answer these questions. Science tells us the what but not the why. Science can only discover the laws of nature but cannot tell us why there are laws. Science cannot even explain why the universe can even be understood by science at all.

Science cannot explain the existence, orderliness and fine-tuning of the physical laws that enable temporal order. So, Swinburne turns to another sort of explanation. We know from experience that temporal regularities can be caused by persons. Human behaviour and technology often follow temporal regularities, such as sleeping at night. The explanation of those temporal regularities is that they were designed, i.e., intentionally created by an intelligent mind. Swinburne calls this a personal explanation.

The only available and therefore best explanation of the temporal regularities in nature is a personal explanation. Only God would have the power to have designed the laws of physics. So, God exists.

Multiverse theory: Max Tegmark, a physicist, suggests a scientific explanation of fine tuning. The multiverse theory suggests our universe is just one of an infinite number of universes, all of which have different laws of physics. So, the fact that some universes are so perfectly fine tuned for human existence doesn’t require any special explanation, since there are an infinite number of every possible configuration of universes.

Swinburne’s defence: However, there is very little evidence for the multiverse theory. Polkinghorne agrees and claims that the multiverse theory is a ‘bold speculation’, a ‘metaphysical guess’.

Hume’s unique case argument applied to Swinburne. Hume insists that there is a standard of empirical evidence required to justifiably infer design.

Swinburne claims that because science cannot explain temporal order, personal explanation is the best explanation.

However, it seems that Hume would respond that Swinburne is not justified in relying on an inference to the best explanation style argument. Hume thinks that unless we have empirical evidence of the creation of the universes, or other universe to compare ours to, then we are not justified in inferring design. Without such experience, we should suspend judgement.

Swinburne could be correct that an analogy between temporal order in the physical laws of the universe and human creation of temporal order is the best explanation we have.

Swinburne could even be correct that science will never be able to provide us with a better explanation.

Yet, according to Hume, this is irrelevant. The wise person proportions their belief to the evidence. We have insufficient evidence to judge whether the universe is designed. Even our best explanation is not empirically valid and so we should suspend judgement and accept that we do not know why the universe is the way it is.