Why 'Life Had To Have Been Designed' Is a Terrible Justification for God's Existence

"Just look around you. Look at life, and the universe, and everything. Doesn't it seem like it had to have been designed?"

A lot of arguments for religion are very bad indeed. A lot of arguments for religion aren't even arguments: they're deflections, excuses for why the believer isn't making an argument, bigoted insults, expressions of wishful thinking, complaints that atheists are mean bad people to even ask for an argument, heartfelt wishes that atheists would just shut up.

But some believers do take the question "Why do you believe in God?" seriously. Some believers don't want to believe just out of blind faith or wishful thinking; they care about whether the things they believe are true, and they think the question "What evidence do you have to support this belief?" is a valid one. They think they have good answers for it. They think they have positive evidence for their spiritual beliefs, and they're happy to explain that evidence and defend it.

The argument from design -- that life had to have been designed, because it just looks so much like it was designed -- leads the list of these answers. According to Michael Shermer's How We Believe, the argument from design is the single most common reason religious believers give for why they believe.

Since these people are taking atheists' questions about their religion seriously, I want to return the favor, and take their religious answer seriously.

And I want to talk about why this is really, really not a good answer. At all. Even a little bit.

Have You Heard of This Darwin Fellow?

The argument for design argues that the evidence for God lies in the seemingly inexplicable complexity and functionality and balance of life: of individual life forms, of specific biological organs and systems, of the ecosystem itself.

"Look at the eye!" the argument goes. "Look at an ant colony! Look at a bat's sonar! Look at symbiotic relationships between species! Look at the human brain! They work so well! They do such astonishing things! Are you trying to tell me that these things just...happened? How can you possibly explain all that without a designer?"

Not to be snarky, but: Have you heard of this Darwin fellow?

I'm assuming that I'm not talking to creationists here. Creationists definitely do not count as people who care about reason and evidence and whether what they believe is consistent with reality. I'm assuming that I'm talking here to reasonably educated people, people who accept the basic reality of the theory of evolution...but who still think that God had to have been involved in it somehow. I'm assuming that I'm talking to people who understand that the theory of evolution is supported by a massive body of evidence from every relevant field of science (and from some that you might not think of as relevant)...but who still think that evolution, while a jolly clever idea, is still not quite sufficient to explain the complexity and diversity and exquisite high functioning of biological life.

To those people, I say: You really need to study evolution a little more carefully.

The theory of evolution is completely sufficient to explain the complexity and diversity and exquisite high functioning of biological life. That's exactly what it does. The whole point of evolutionary theory is that it explains exactly how life came to be the complex and amazingly balanced web of interconnections that it is, with species beautifully adapted to their environments -- not through design, but through natural selection and descent with modification. It explains it beautifully, and elegantly, and with no need for any supernatural designer to explain anything.

Descent with modification; the survival and reproduction of life forms that are best able to survive and reproduce; great heaping gobs of time. That's all it takes. (Here's a good primer on what evolution is and how it works; for a more detailed explanation, you can check out Why Evolution Is True by Jerry A. Coyne, or The Greatest Show On Earth: The Evidence for Evolution by Richard Dawkins, or Evolution: What the Fossils Say and Why It Matters by Donald R. Prothero, or... oh, you get the idea.) The more familiar you become with evolution, the more you understand that it is more than sufficient to explain what seems at first glance to be design in biological life.