Hume criticism of the teleological argument questions the strength of Paley’s watchmaker analogy (although it must be noted that Hume’s criticism came 23 years before Paley made his argument) by debating whether the universe and watches are actually alike. If the universe and watches were alike, then it would be supposed that the universe has a designers because as Hume says ‘like effects presuppose like causes.’ For instance, if I saw two chocolate Mars bars I would be able to assume that they had the same cause, i.e. the same starting ingredients. However, Hume rejected Paley’s use of analogy as the watch and the universe are not similar. This is because the watch is mechanical while the universe is organic. We can assume a house has an architect and a builder because a house is unnatural and cannot be produced by nature. The universe on the other hand is natural however (unlike the watch used in Paley’s analogy), so the universe and the watch are not ‘like effects’, with Hume saying the analogy would work just as well between the watch and a giant vegetable. Evidently, it would not be plausible to conclude that the vegetable was designed. People have seen watches being made, so it cannot be debated whether they are designed, but no one has seen a universe being constructed neither is it as evident of design as the watch. Because of this Paley’s is flawed and cannot infer a designer.

Although the world appears designed, this does not mean that the best explanation for this appearance in design. Darwin’s theory of natural selection proposes that design could come about without anything actually being designed. Millions of mutations randomly take place in a creature, most of the, disappearing without trait. Traits that coincidentally help a creature to survive spreads, because the creature is better suited to its environment, and so can reproduce easier. As a result, more creatures end up with the specific trait, as those without it will die due to not being as ‘genetically advanced’ or adapted to their environment as other competitors. This is what is known as the ‘survival of the fittest’. What appears to be designed and complexity is just evidence of good functioning. We don’t need to say that living things are actually designed (which would require the existence of a designer). Dawkins agrees with this, arguing that the process of natural selection is the ‘blind watchmaker’ of nature as natural selection in itself has no purpose and does not plan for the future.