How do we draw the line? How do we know when to punish a teacher for being wrong and when to insist that teachers have a right to express their views on controversial topics? A new bill in Montana again insists that creationist teachers should have legal protection to teach their views. Nor is this simply a Montana question. From its headquarters in Seattle, the Discovery Institute has proposed a model bill for legislatures nationwide. From Alabama to Colorado, Florida to South Dakota, lawmakers have offered similar bills.

The basic argument is the same: Teachers must be allowed to teach the full range of ideas about evolution and the origins of life. Should they? And if they shouldn’t, why not?

These are not easy questions, though they might seem so at first. Opponents of these sorts of creationist “academic freedom” laws scoff that no teacher has the right to tell students things that aren’t true. Supporters, on the other hand, might insist that this is a simple question of teachers’ rights to academic freedom.

Neither of those positions captures the complexity of the situation, though. For those of us who oppose these bills, it seems obvious that teachers must not be allowed to tell students things that are not true. As Glenn Branch of the National Center for Science Education put it, Montana teachers do not have the right to teach “bunk.”

The hard question, though, is who decides on the definition of bunk, and how. Historically, we’ve seen teachers persecuted for unpopular political beliefs. As historian Clarence Taylor has described, in the early 1950s eight New York teachers were fired for their leftist sympathies.

Throughout the twentieth century, as I argued in my new book, progressive teachers and school administrators struggled to protect their rights to their political opinions. These educators insisted on their right to hold controversial opinions. More pertinent, they insisted on their right to teach students about these ideas.

In hindsight, it’s clear that the rights of these teachers were egregiously violated. What’s worse, the climate of public education as a whole was degraded by these educational witch-hunts. Only a few teachers were actually purged, but a climate of fear pushed teachers and students to hew more closely to the patriotic party line. That’s not good education.

So creationists ask: Aren’t these bills protecting the same right? Don’t creationist teachers have the right to present all sides of scientific questions about origins?

Yes and no. As philosopher Harvey Siegel and I argue in our upcoming book, creationist teachers and students DO have enormous rights in public-school classrooms. Too often, evolution mavens get too wrapped up in winning culture-war battles to admit it. Far too often, science teachers imply that students need to believe evolution; earnest teachers want students to acknowledge the fact that real knowing means abjuring supernatural explanations of events. Creationist students have every right to dissent from such beliefs. If students want to believe that the earth is 6,000 years old, or that the earth is a floating turtle, or any other sort of thing, they have every right to do so.

Public schools must welcome a plurality of religious beliefs. Creationists—teachers and students alike—must be defended in their quest to protect their faith from assault, even if that assault is only implied or suggested.

By that same token, however, these sorts of academic bills fail on two counts. First, students in public schools have the right to be protected from religious indoctrination. No teacher may preach religious doctrine. Though creationists might howl in protest, even the most intelligently designed creationist bills have religious goals. Instead of protecting teachers’ rights to teach controversial subjects, in effect these sorts of academic freedom bills protect a non-existent right to preach a certain religion-friendly doctrine in public-school classrooms.

Second, students in public schools have the right to learn the best ideas available. When issues are truly controversial, students must be exposed to those controversies. But when ideas are not controversial, students must not be forced to mull false ideas as co-equal to truer ones.

This is not only an evolution/creation idea. In history classes, for example, students should not learn that the South won the Civil War. Or that most enslaved people preferred bondage to freedom. These ideas are held by lots of people, but that doesn’t make them just as true as other historical ideas.

Teach the controversy?

In science classes, the sorts of dissent that people such as Montana legislator Clayton Fiscus wants to protect are not equally scientifically valid. True academic freedom does not include the right to offer worse scientific ideas as equal to better ones. True academic freedom does not include the right to preach religious ideas as facts.

So do teachers have the right to be wrong? Yes, indeed. But they do not have a right to encourage students to believe any particular sort of religious belief. Nor do they have the right to pretend two sets of ideas are equally valid when they are not.