There is an old argument that creationists like to trundle out from time to time, called the Watchmaker Argument. It’s been roundly defeated by evolutionary biologists (many times over), but I’d like to address a part of it that most modern evolutionists skip over, because it’s an interesting philosophical exercise.
In 1802, William Paley published, Natural Theology, which was an extended argument in favor of the existence of God, and a refutation of the current ideas about evolution. Astute readers might have noticed that 1802 was 57 years before the publication of On the Origin of Species by Charles Darwin. In fact, Darwin took the arguments in Natural Theology very seriously and went to great lengths to refute them. I suppose he might have had it in front of him while he composed his treatise, although I’m not enough of a historian to say.
Anyway, the central argument of Natural Theology goes like this. Say you’re walking along, thinking evolutionary thoughts to yourself, when you come upon a pocket watch. The watch was probably planted there by a creationist, but that’s neither here nor there. Anyway, you pick up the watch and examine it, and immediately understand that it is a complex device that was been made by a watchmaker. It did not just pop up out of the ground like a stone.
So far so good. The next step of the argument says that if the watch is complex and was made by a watchmaker, then a living being, which is even more complex must also have been made by… Something. Presumably not a watchmaker, or we would all be better at getting to our appointments on time. Anyway, let’s call the “Something” God. So, God must exist and all living things were made by God, QED. There are a lot more details, but we’ll stop here for now.
This was a very successful argument in its time, mostly because Darwin hadn’t worked his magic yet. The crux of the argument is that we can’t think of any way for a watch to form itself. So it must have had a watchmaker, and by analogy, because we can’t think of any way for a living thing to form itself, so there must be (or once have been) a Designer, God.
And then Darwin came along and thought of a way for an organism to in effect form itself. The nifty thing about On the Origin was not that it introduced the concept of evolution, but that it proposed the first viable way for organisms to change without the aid of an external designer or, for that matter, any mystical force. Natural selection is a process, an algorithm, if you like, that occurs blindly over the aeons. Let’s review it.
Assume there are 50 organisms of a certain species living in a particular area. They are not identical. Because they have differences, some of them will be better able than others to amass resources and reproduce. Which ones are “better” will depend entirely on the circumstances. But in the next generation, the ones that fit the environment better will have left more descendants. That’s called selection. So long as we can assume that each generation maintains variation, there will be multiple rounds of selection, leading to very different-looking organisms. Hence, evolution.
So, the watchmaker hypothesis fails because it depended only on the unimaginability of adaptive change without external design, and we have just imagined such a scenario. Since it turns out that all the assumptions of this algorithm are in fact met in the real world, and there are multiple other supporting lines of evidence (like fossils), we can say that the Watchmaker hypothesis is doomed.
So far, this is the line of reasoning advocated by most evolutionary biologists.
But I want to go back and look at the watch again, because we are left with a lingering question: How did we know that the watch was made by a watchmaker? How do we know that it didn’t evolve? We need to explain why we can look at a watch and conclude one thing about it, but look at an organism and conclude another.
Imagine that you are walking in the field, as before, but this time, assume also that you are primitive and have never seen a watch before. You pick it up. It ticks, and the hands move on their own.
What process made this thing? How do you reach your conclusion?
I argue that we are perfectly capable of differentiating between something that grows organically and something that was made by an artificer. We do it by analogy.
You have never seen a watch, but you have wide experience of your environment, and you have manufactured a thing or two yourself. You know that things like arrows and fish hooks are made by taking small rocks or bones, shaping them intricately and attaching them to other things. You know that living things have flesh and bone.
You also know that living things grow and reproduce on their own, without external aid. You know that the process of making one is not the same as the process of making a fish hook.
The watch looks like it is made of small, strange rocks. Hence, you conclude that it is probably not quite alive – except in so far as a bow or a river is alive – and so might have been man-made.
But if you had found a dead animal that you had never seen before, you probably would not conclude that it had been made by a person. It was born from some sort of parents, then grew and died. And you can reach that conclusion because it has the characteristics of other creatures that you know also grow and die.
To argue that the watch evolved would require that we could see watches grow and reproduce. And that would be an extremely silly thing to do – except that Paley has already done it! Part of Paley’s argument did in fact require the reader to imagine a watch that could self-assemble and reproduce itself.
But notice that once the watch can reproduce itself, all we need is variation, small errors in reproduction, and we have all the requisites for evolution by natural selection. Paley is hoisted by his own petard!
But how do we start the process? Didn’t we need an artificer for the first organism, just as we needed a watchmaker for the first evolving watch?
Now we’re getting into the realm of abiogenesis: the evolution of life from non-life. We have ideas about how it can happen, but that’s a story for another time.