What is evolution?
The theory of evolution was initially proposed in 1859 by Sir Charles Darwin in his book “On the Origin of Species”. The theory was co-discovered by Alfred Russel Wallace, but Darwin receives the lion’s share of the credit; indeed, some people refer to the theory as Darwinism. Though the theory is fascinating, its details are outside the scope of this article. Suffice it to say that this scientific theory lays out an extremely elegant explanation for the diversity and complexity of life forms, all without the need of a creator.
The theory of evolution forced humans to see themselves as animals for the first time, on an equal footing with all other organisms on the planet. Not God’s special project. That rubbed many people the wrong way. Each religion has its own creation story, an explanation of how some great creator brought the world, and everything in it, into existence. Creation stories explain the complexity and diversity of life as the intention of an intelligent being. Belief in these creation stories is called “creationism”.
What is Intelligent Design (ID)?
According to the Discovery Institute,
The theory of intelligent design holds that certain features of the universe and of living things are best explained by an intelligent cause, not an undirected process such as natural selection.
That is, an intelligent designer (eg. God) is a more likely explanation for life and the universe than any natural process. How do they reach that conclusion?
Such research is conducted by observing the types of information produced when intelligent agents act.
In other words, ID adherents study the properties of things they know are designed (by humans). They refer to this ensemble of properties as “complex and specified information”, or CSI. Thus, if something is designed, it has CSI, a sentiment echoed on the same web page,
Design theorists hypothesize that if a natural object was designed, it will contain high levels of CSI.
Then these scholars look for other non-man-made objects or systems that have CSI. When they find them, they conclude that the objects were designed.
When ID researchers find [CSI] in biology, they conclude that such structures were designed.
This conclusion pops up repeatedly, like here
… specified and complex information is known to be a reliable indicator of design.
Problems with ID
Here we run into our first glaring problem with ID. Here is the logic of that argument.
- All designed objects exhibit CSI.
- Natural object X has CSI.
- Thus, X was designed.
This is what we call a non sequitur, a conclusion that does not logically follow from the argument. Here is another more familiar version of the same logical argument.
- All rapists are human.
- You are human.
- Thus, you are a rapist.
No, I didn’t think you were. The conclusion doesn’t follow. Just because every designed object exhibits CSI, it doesn’t mean that everything that exhibits CSI is designed. Here is a graphical way of understanding the logic error. Notice that X is an object with CSI, but is not designed.
Not all ID arguments follow that faulty logic. Others focus-in on objects that exhibit CSI, and try to convince you that the object could not have arisen from natural, unguided processes. In essence, it’s the reverse of (1) above, that is, “All objects that exhibit CSI are designed.”
Michael J. Behe of Lehigh University has argued that so-called irreducible complexity fulfills this role. An irreducibly complex system consists of interdependent parts such that if any one part was removed, the system would fail to function. According to Behe, one such system is the bacterial flagellum, a tiny hair-like structure that rotates like an outboard motor to propel the bacteria cell. Other examples include the eye, the wing, blood coagulation, and species symbiosis. Behe says that if you take away one component from these systems, the remaining subsystem will have no function and have no purpose or benefit. And if that’s true, then how could these complex systems have arisen by the process of evolution that requires only advantageous traits get passed down the generations? Behe states that they can’t, so the only other alternative is that these systems did not evolve, but were instead designed by an intelligent agent.
The problem with that argument is with the assumption that an incomplete system has no benefit. Each alleged case of irreducible complexity is soon discredited by scientists in the peer-reviewed literature (for a small list, see this). It turns out that Behe couldn’t think of how an incomplete system could be beneficial, so Behe concluded that it must have been designed. This is called the argument from ignorance, also knows as the “god of the gaps” argument. Not being able to explain something does not mean it’s not explainable. This is the most fundamental error in the ID argument.
Not that it’s relavant at this point, but another leader of the ID movement is William Dembski, of Southwestern Baptist Theological Seminary. He claims to have worked out an objective way to measure CSI, able to distinguish between the complexity generated by randomness and the complexity generated by intelligent design. It can’t. Dembski’s publications are not peer-reviewed by the scientific community, and have been thoroughly discredited in the scientific literature by Elsberry and Shallit.
So, why doesn’t ID avoid those fallacious arguments, and instead put forward a serious scientific theory? The answer to THAT is in the definition of science.
What is science?
According to the Oxford Dictionaries, science is
the intellectual and practical activity encompassing the systematic study of the structure and behaviour of the physical and natural world through observation and experiment
Another source defines science as “systematically acquired knowledge that is verifiable.” Or, in the words of Richard P. Feynman, “Science is a way of trying not to fool yourself.” It’s a methodology for how to go about gathering knowledge about the world in an objective fashion. That methodology is designed to avoid the pitfalls of subjective human perception.
I’d like to draw your attention to two key points about science:
- Scientific claims have to be falsifiable. That is, there must be an experiment that could – at least in principle – refute or disprove the claim.
- Anyone is able – at least in principle – to repeat the experiments. Results are only valid if they are reproducible.
People come up with some pretty out-there claims about how the world works (water memory, quantum physics, iridology, relativity). How does one convince skeptics that they’ve got a valuable piece of knowledge? Answer: They demonstrate it. This is exactly where we get the notions of falsifiability and repeatability. Science takes beliefs and either demonstrates that they are false, or turns them into objective knowledge. As a consequence, science is objective and self-correcting.
Is ID science?
Many ID proponents bemoan the fact that science explicitly excludes the supernatural. That’s true, it does. Why? According to the Oxford Dictionaries,
(of a manifestation or event) attributed to some force beyond scientific understanding or the laws of nature
That is, “supernatural” is defined as everything outside of science. There’s a good reason for that. If we can’t test it and observe it, then what good is it? If I claimed that a miracle occurred, how does that help us understand how the universe behaves? As soon as ID plays the supernatural card, they exclude themselves from science.
ID evangelists claim that ID is an important theory because it provides a framework through which scientists can make hypotheses… based on the design principle. That is, scientists benefit when they approach a complex system as though it were intelligently designed. Nothing could be further from the truth. What ID theory gives us is a list of systems that we label as designed, but since those systems did not arise by natural processes, we can’t form any scientific conclusions from them. All we can do is try to decipher the intention of the designer; hardly a useful exercise.
More importantly, phenomena that were once considered supernatural are today understood as science. God doesn’t hold the stars up; they follow trajectories well understood by physics. Lightning isn’t Zeus getting angry; it’s an atmospheric discharge of electricity. Things are unexplained until they are explained. The question is, what do you do with things that aren’t explained yet? ID would have you believe that God (or some other intelligence) did it.
Then why is ID popular?
There was a pre-scientific time when people lacked a formal system for establishing which claims were true, and which claims were false. In that era, saying that the stars were lights on a black sheet probably seemed more reasonable than huge glowing balls of gas billions of kilometres away. But there was no systematic way to separate the right from the wrong; people had only their intuition.
In those days, religions offered the most satisfying explanations of why the world is the way it is. Intelligent design, and other forms of creationism, trace their roots back to religion (though ID proponents will deny this until they turn blue in the face).
We even have scientific hypotheses, based on the theory of evolution, that explain why humans have a tendency to detect intelligent agency.
It’s not at all surprising that religious world views still abound. And it’s relatively easy to confuse people about theories that have complex ensembles of evidence. The theory of evolution can be quite subtle, but it has mountains of evidence from many fields of science (for a good recent survey, read The Greatest Show on Earth by Richard Dawkins). ID advocates use grossly simplified and incorrect versions of the theory to persuade religious people to suspend their disbelief until the next sermon.
Science can be hard to understand. Our brains didn’t evolve to untangle the complexity and nuance of all the laws of nature. It’s natural that we should prefer a simplistic world view.
But these cognitive challenges do not excuse us from reality. Almost all species eventually go extinct, and humans are no exception. Our best hope for long-term survival is to use our strongest asset, our brains, to understand who we really are, and where we fit in the cosmos.