The original reasoning put forward by Richard Dawkins comprised the following text:
1. One of the greatest challenges to the human intellect… has been to explain how the improbable appearance of design in the universe arise.
2. The natural temptation is to attribute the appearance of design to actual design itself. In the case of a man-made artefact such as a watch, the designer really was an intelligent engineer. It is tempting to apply the same logic to an eye or a wing, a spider, or a person.
3. The temptation is a false one, because the design hypothesis immediately raises the larger problem of who designed the designer. The whole problem we started out with was the problem of explaining statistical improbability. It is obviously no solution to postulate something even more improbable. We need a ‘crane,’ not a ‘skyhook,’ for only a crane can do the business of working up gradually and plausibly from simplicity to otherwise improbable complexity.
4. The most ingenious and powerful crane so far discovered is Darwinian evolution by natural selection. Darwin and his successors have shown how living creatures, with their spectacular statistical improbability and appearance of design, have evolved by slow, gradual degrees from simple beginnings. We can now safely say that the illusion of design in living creatures is just that — an illusion.
5. We don’t yet have an equivalent crane for physics. Some kind of multiverse theory could in principle do for physics the same explanatory work as Darwinism does for biology. This kind of explanation is superficially less satisfying than the biological version of Darwinism, because it makes heavier demands on luck. But the anthropic principle entitles us to postulate far more luck than our limited human intuition is comfortable with.
6. We should not give up hope for a better crane arising in physics, something as powerful as Darwinism is for biology. But even in the absence of a strongly satisfying crane to match the biological one, the relatively weak cranes we have at present are, when abetted by the anthropic principle, self-evidently better than self-defeating skyhook hypothesis of an intelligent designer.
Therefore, God almost certainly does not exist. 1
Put in argument form, can be formulated as follows:
P1. We see evidence of apparent design
P2. One hypothesis for the cause of apparent design is God
P3. If God is the cause of the apparent design then he must be complex and we must also account for who designed God (which would be even more complex than God)
P4. Natural selection is a much simpler hypothesis for apparent design (even though we currently have a weak explanation of the required physics)
C. Therefore God almost certainly does not exist
The reason why the Boeing 747 argument is so named is in response to Fred Hoyle reportedly saying that the:
probability of life originating on Earth is no greater than the chance that a hurricane, sweeping through a scrapyard, would have the luck to assemble a Boeing 747. 2
The argument which claims to conclude that God almost certainly does not exist, has been heavily criticised from both theists and atheist philosophers, mostly notably for being a non sequitur. The conclusion does not at all follow from the premises.
William Lane Craig commented on this argument’s inference to the conclusion:
This argument is jarring because the atheistic conclusion, “Therefore, God almost certainly does not exist” doesn’t follow from the six previous statements even if we concede that each of them is true and justified. At most, all that follows is that we should not infer God’s existence on the basis of the appearance of design in the universe. But that conclusion is quite compatible with God’s existence and even with our justifiably believing in God’s existence on other grounds. Rejecting design arguments for God’s existence does nothing to prove that God does not exist or even that belief in God is unjustified. 3
We can replace the overly ambitious conclusion with the more appropriate “Therefore God is not the best hypothesis for apparent design”, in which case the argument becomes relevant and interesting. However this is a much weaker conclusion, as David Glass has pointed out:
A particular problem is that his argument for the improbability of theism rests on a highly questionable application of probability theory since, even if it were sound, it would only establish that the prior probability of God’s existence is low, a conclusion which is compatible with the posterior probability of God’s existence being high 4
There are also multiple objections to the premises of the argument, of which some are outlined below. In summary, it is difficult to find the argument compelling when comparing the simplicity and complexity of unknowns with unknowns.
The criterion of simplicity
The argument rests on the assertion that natural selection is a simpler hypothesis (less complex and therefore more probable) than a designer. While simplicity is important, simplicity as the main criteria for the best hypothesis is a controversial assertion.
A common concern is that notions of simplicity appear vague, and judgments about the relative simplicity of particular theories appear irredeemably subjective. Thus, one problem is to explain more precisely what it is for theories to be simpler than others and how, if at all, the relative simplicity of theories can be objectively measured. In addition, even if we can get clearer about what simplicity is and how it is to be measured, there remains the problem of explaining what justification, if any, can be provided for choosing between rival scientific theories on grounds of simplicity.
It should be noted, however, that not all scientists agree that simplicity should be regarded as a legitimate criterion for theory choice. The eminent biologist Francis Crick once complained, “[w]hile Occam’s razor is a useful tool in physics, it can be a very dangerous implement in biology. It is thus very rash to use simplicity and elegance as a guide in biological research” (Crick, 1988, p138).
Hence, while very many scientists assert that rival theories should be evaluated on grounds of simplicity, others are much more skeptical about this idea
William Lane Craig has said:
there are many other factors besides simplicity that scientists weigh in determining which hypothesis is the best, such as explanatory power, explanatory scope, and so forth. A hypothesis that has, for example, broader explanatory scope may be less simple than a rival hypothesis but still be preferred because it explains more things. Simplicity is not the only, or even most important, criterion for assessing theories!
It is not at all clear that natural selection is a simpler hypothesis (and more probable) than a single designer
However for the sake of argument if we grant that simplicity is the only criteria to be used then Graham Veale has questioned the simplicity of the natural selection hypothesis:
it is unreasonable to describe evolution by natural selection as a simple state of affairs. Evolution depends on the existence of replicators: structures which cause copies of themselves to be made; each acts as its own template for copying. The copying system must allow for a little variation in each new generation; this allows a population of variants to come into existence. Yet the copying process must also be very reliable – otherwise beneficial variations would not be preserved.
Furthermore, natural selection requires more than variation and very reliable replication. The replicators must exist in an environment in which they compete for resources. Finally, to explain the taxonomic diversity and organised complexity of our world, these replicators must be able to combine to form vehicles – that is, structures (for example, organisms) which work to propagate their replicators.
It is remarkable that such a replication process is even possible. Evolution can only take place because the laws of physics and chemistry allow inorganic molecules to combine to form organic molecules which can become replicators of the correct kind. So evolution by natural selection depends upon specific laws of physics and chemistry, and extraordinarily precise cosmological constants. The point here is that natural selection is not a simple process; it depends on an extremely complex and improbable states of affairs.
The initial state of affairs that bring about natural selection, as well as the ongoing states of affairs needed, are themselves highly complex and improbable and far from simple. The probability of a life permitting universe is so vastly improbable as to be outrageous.
In just one example…
“Reasons to Believe” lists hundreds of these constants and qualities:
- Fine-Tuning for Life in the Universe
- Fine-Tuning for Intelligent Physical Life
- Probability Estimates for Features Required by Various Life Forms
- Probability Estimates on Different Size Scales for the Features Required by Advanced Life
William Lane Craig said:
Dawkins seems to confuse the simplicity of a hypothesis with the simplicity of the entity described in the hypothesis.  Positing a complex cause to explain some effect can be a very simple hypothesis, especially when contrasted with rival hypotheses. Think, for example, of our archaeologists’ postulating a human fabricator to explain the arrowheads they discovered. A human being is a vastly more complex entity than an arrowhead, but the hypothesis of a human designer is a very simple explanation. It is certainly more simple than the hypothesis that the artifacts were the unintended result of, say, a stampede of buffalo that chipped a rock to look like an arrowhead. The point is that it is rival hypotheses are assessed by the criterion of simplicity, not the entities they postulate.
It is difficult to see why natural selection should be considered a simpler and more probable hypothesis than a designer especially when it is not clear how complex a designer would actually need to be.
It is not at all clear that the mechanism which would allow natural selection to occur is a simpler (and more probable) hypothesis than a designer’s designer
Dawkins contends that:
the design hypothesis immediately raises the larger problem of who designed the designer…It is obviously no solution to postulate something even more improbable. 5
It is not a scientific problem to postulate an even more complex explanation of an explanation as long as it is the best hypothesis and has more explanatory scope etc. However we know nothing of the required complexity of a designer’s designer or why it could not be the case that the designer’ designer could be equally if not less complex than the designer, in the same way that complexity could naturally arise from simplicity as in the case of the natural selection hypothesis.
To be consistent, the natural selection hypothesis also immediately raises the larger problem of what caused the enormously improbable initial state of affairs for natural selection to occur.
Dawkins unparsimonious appeals to the multiverse to explain the fine tuning required for natural selection however appealing to a multiverse has its obvious problems for any argument which claims that God is improbable:
it is not clear a multiverse explains anything anyway – stating instead that everything is possible somewhere. If science routinely proceeded on that basis, it would have to conclude that God exists in some universes, following Richard Dawkins’ reasoning that whilst God is highly unlikely, the possibility cannot be ruled out tout à fait.6
So it is not at all clear that an appeal to the multiverse does not inadvertently increase the probability of the God hypothesis.
Again it is difficult to see why the mechanism for the highly improbable initial conditions in natural selection should be considered a simpler and more probable hypothesis than a designer’s designer.
The Ultimate Boeing 747 Gambit argument which forms part of the central argument in the God Delusion has rightly been accused of being an obvious non sequitur.
It becomes relevant if we weaken the conclusion, however the most that can be concluded (if the premises are true, which is controversial) is that God is not the simplest hypothesis for apparent design and that the traditional argument from design is defeated, of which the jury is still out. As the atheist philosopher Graham Oppy has said:
…the claim that Darwin and his successors did utterly demolish the argument for biological design is not obviously correct. 7
- Dawkins, The God Delusion
- Dawkins, The God Delusion
- William Lane Craig. 2018. The New Atheism and Five Arguments for God. [ONLINE] Available at: https://www.reasonablefaith.org/writings/popular-writings/existence-nature-of-god/the-new-atheism-and-five-arguments-for-god/. [Accessed 3 April 2018].
- Dawkins, The God Delusion
- Arguing about Gods, Graham Oppy p237