On slippery slopes, evidence and fairness

Commenter Geremy worries about the long-term implications of allowing intelligent design in science class:

I think my problem with [reading] the paragraph is the slippery slope it might lead to in the future. There’s value in bright lines about what belongs and doesn’t belong in a Science classroom because it protects against future encroachment of ideology so that you don’t have to fight every battle as it comes up.

Let’s leave aside that this response avoids the main questions on this blog: Why is there “value” in bright lines? Who decided that? And who decides what belongs or doesn’t belong in a science classroom? Let’s simply accept Geremy’s premises. Even then, I question whether there is any slippery-slope. I see two examples of ideology encroaching on science class: climate change and evolution. Other than these two, what future encroachments are we worried about? Is there a wide push to teach astrology as science?

I’m reminded of the run-up to Obamacare. Some people worried that if the government could force us to buy health insurance it could also force us to buy broccoli. Austin Frankt helpfully noted that we cannot treat “a slippery slope argument as a logical one, when in fact it is an empirical one” (emphasis added). The logical possibility that A might lead to B is not by itself argument enough to oppose A. You need evidence. So I would gently push Geremy, or anyone else, to provide supporting data for the slippery-slope hypothesis. I personally don’t see any reason to worry. Rather, I see that an overwhelming majority of Americans support science research and believe the positives outweigh its negatives. Americans have some of the most favorable attitudes towards science and technology in the world.

I’m also reminded of how some social conservatives treat sex education. They argue, as scientists do for creationism, that teaching sex ed will have catastrophic long-term consequences. How did the scientific community respond? By gathering evidence! We didn’t speculate on the outcome or make assumptions. We conducted solid scientific research to make our case. Why don’t we do the same for creationism?

If we’re going to question slippery-slope arguments (and I think we must), we should do so for all groups all the time. Isn’t it unfair to simply pick-and-choose when we oppose such arguments? Shouldn’t we at least try to be consistent?

With all that, I’ll add a wrinkle to my thought experiment to better make my point. Assume that other than evolution everyone always agrees with the prevailing scientific consensus. So now there is no worry at all about the slippery slope. Do we still have a problem if one group of students hears that intelligent design is a valid alternative to evolution?


  1. I worry that that the subject of creationism or ID is not the end result but just the product of a type of thinking. If my congressional representative believed in creationism, then fine. But if my congressional representative believed in creationism as part of a strong belief that there should be more, say, explicit Christian teachings in public school, then that goes against the principles which I believe. Is it possible to separate those two situations in the eyes of the voter?

  2. Yes, we still have a problem if one group of students hears that intelligent design is a valid alternative to evolution. The existing framework of ideas for intelligent design (specified complex information, irreducible complexity, Dembski’s design filter, et cetera) are not used in biological research, even by ID proponents. We should not imply otherwise. By stating that intelligent design is a valid alternative to evolution, we are conveying that false implication.

    1. Thanks again Robert. I appreciate your many comments! I don’t believe I said ID is a “valid alternative.” I was simply arguing that the horror stories predicted for people who learn evolution will probably not materialize. It’s a (very bad) slippery slope argument. In any other context, we would call out how bad this argument is. We should do the same here.

Leave a Comment

Your email address will not be published. Required fields are marked *