told him not to debate the merits of evolution with the noted young-earth creationist, Ken Ham, Bill Nye went ahead and did it. Not only that, he did it in the belly of the beast: Ham’s own Creation Museum in Petersburg, Kentucky.

Good for him. As I have argued many times in this space, people who believe things strongly have a moral obligation to persuade others. Ken Ham is not a lone voice in the wilderness. Millions of people believe as he does, and it does no good to call them all stupid extremists. Engaging with people whose beliefs one considers mistaken is part of what it means to be a citizen.

And by all accounts, Nye won the debate. Except for those accounts where he lost the debate. And the accounts that say that nobody really won because everybody is going to keep believing what they have always believed no matter what anybody said — which is usually how these things turn out. Maybe the only indication that anybody actually did win is the fact that, after the debate, no less a Christian stalwart than Pat Robertson said that young earth creationism is ridiculous and that Ham should “put a sock in it.”

Robertson’s critique, I think, actually does get to the problem that plagued the Nye-Ham debate — and that plagues the whole “Evolution vs Creationism” controversy in our public discussions of science today. The simple fact is that it is not a debate — it is two debates, only one of which has anything to do with science.

One position, which we can call “Creationism,” holds that the existence of stuff implies both a creator and a purpose -- and most creationists believe that one or more of the religious texts available in the world contains clues to that purpose -- if not a complete history -- of the creation. Opposed to the philosophical position of Creationism is a philosophy that we might call “Accidentalism,” or a belief that matter in the universe, and life on earth, emerged without any external influencers. Stuff, according to acidentalists, just happened.

“Creationism vs Accidentalism” is not a scientific debate, since it makes no testable assertions and generates no falsifiable hypotheses. It is a philosophical debate about the cosmic master narrative. It requires us to make and defend assertions about the ultimate nature of reality and about the extent to which human beings have access to this ultimate nature. Such questions will always be beyond the modest organon of the scientific method.

The second debate, however, involves the mechanism through which life on earth has developed. There are really only two possibilities for this mechanism. One of them is evolution by natural selection. The other one is “Magic.”

Unlike “Creation,” Evolution does not pretend to be a master narrative. It tells us nothing about the ultimate nature of reality or about the great designs of forces beyond our comprehension. It is a specific mechanism that produces changes in populations of organisms over long periods of time. We can watch it happen in a petri dish, and, whether we are talking about dinosaurs or microbes, the mechanism works the same.

The specific mechanism of natural selection works equally well as part of either one of the cosmic master narratives. It could be part of the plan of an intelligent Creator. Or, it could be one of the lucky breaks that go into the cosmic theory of Accidentalism. It is not necessary to decide which cosmic narrative to subscribe to before learning how the mechanism works.

But natural selection generates oodles of testable hypotheses, and scientists have been testing them for the last 150 years. Though this has required corrections at the margins, Darwin’s theory of evolution has performed nearly flawlessly under nearly every possible set of experimental conditions. Our students need to know this, and they need to learn how to conduct their own experiments. Only somebody who has studied evolution deeply will ever be able to falsify an evolutionary hypothesis. This is how science works.

When we frame the argument as "Creation vs Evolution," we are asking people to chose between a philosophical principle and a scientific mechanism. This is not apples and oranges; it is apples and France, and it will almost always lead to people talking past each other in something that only vaguely resembles a debate.

So let's have two debates instead. Let's have philosophers and theologians debate the ultimate questions of the cosmos and the proper role of Genesis in understanding the same. And let's have scientists argue over the most likely mechanisms that produced increasingly complex forms of life on Earth. Then, the millions of Americans who have no problem believing in both natural selection and a divine creator might see their position represented in public conversations about religion and science.