A creationist canard holds that if you find a watch lying on the ground, you would know it had to have been created, and therefore, when we look at our world, we know that it too was created.
This is mistaken for a number of reasons. First, most of us today know what a watch is and how it is made. But someone who had never been exposed to a watch before, say a time traveler from 500 CE or an inhabitant of the Nicobar Islands, saw one, he or she would have no reason to presume the timepiece had been designed.
An Answers in Reason blogger using the pseudonym Artificial Agent wrote that if the same person happened upon a cave, they would have “no reason to assume it was man-made, nor that it formed naturally as a result of plate tectonics and rocky structure.”
I saw a documentary in which Papua New Guinea natives were spooked by mirrors and fascinated by matches. With the islanders’ highly limited frame of reference, these inventions may have seemed like supernatural, intelligently-designed products, but this inference would not make it so. Similarly, Artificial Agent cited a BBC program in which a tribesman was taken into an urban area and interpreted a large truck to be a strange beast. This shows what happens when observers lack a frame of reference, and this lack or reference dooms the watchmaker analogy.
On a related note, Artificial Agent wrote that a person might see a puddle and presume the ground was made specifically for it since the puddle had just enough space to hold the water. The truth, of course, is inverse, and the puddle formed the way it did because of the ground’s shape.
And as stated before, we know how watches are made. But have no idea how a planet would be constructed. Thus, it is mistaken to infer that our universe has been created by an intelligent designer just because a watch was made by human hands.
Enlightenment philosopher David Hume argued the universe and a watch have too few similarities to assert that both were created. The universe consists of organic natural substances, while a watch is made of artificial mechanic materials.
In The God Delusion, Richard Dawkins argued that a person could only make a watch if they were more complex than their creation, and this goes for all things created and their creator. Therefore if Earth was created, it would have to have been designed by something more complex than itself. That creator, then, would have to be created something even more complex, and the creator’s creator made by something more complex yet, ad infinitum.