When you’ve been fighting over the same thing for well-nigh 90 years, there’s a good chance some new policy won’t suddenly make it divisive. Nonetheless, that’s what an L.A. Times article, citing critics, suggests about a new law in Tennessee allowing in-class discussions critical of evolutionary theory and other scientific topics:

The measure will allow classroom debates over evolution, permitting discussions of creationism alongside evolutionary teachings about the origins of life. Critics say the law, disparagingly called “The Monkey Bill,” will plunge Tennessee back to the divisive days of the notorious Scopes “Monkey Trial’’ in Dayton, Tenn., in 1925.

You don’t have to be Charles Darwin—or God—to figure this one out: the law was passed because the topic is already divisive. Government-schooling defenders might not want to acknowledge that, and they have been able to keep it slightly hidden by having discussion of creationism de jure forbidden in public schools, but hard evidence reveals that Americans are mightily torn.

Time after time, surveys expose the deep split. Most recently, a 2010 Gallup poll found that 40 percent of Americans believe that “God created humans in present form”; 38 percent accept that “humans evolved, with God guiding”; and 16 percent believe that “humans evolved, but God had no part in the process.” Those numbers have stayed pretty consistent since 1982, the first year for which Gallup has data.

Clearly, whether you want to acknowledge it or not, Americans are already very divided on evolution, and have been for quite some time.

How has what peace we’ve had been kept? Generally, by avoiding evolution in the schools. As Berkman and Plutzer have found, about 60 percent of high school biology teachers either completely avoid or soft-pedal evolution so as not to stir up controversy.

Public schools haven’t been happily chugging along, teaching rigorous evolutionary theory and eschewing any alternative explanations for human origins. A large number have been either teaching evolutionary pap, or nothing.

One of the major arguments government schooling defenders employ against school choice is that choice would lead to a balkanized, divided America. To make that argument, they have to ignore the history of American education—it was largely government-free for about two centuries, and public schools were long grounded in homogeneous communities—and assume that if you force diverse people together they will give up their conflicting values and ultimately engage in a gigantic, society-wide group hug.

Our endless battling over evolution—not to mention incessant fighting over countless other matters—reveals that that just doesn’t happen. You cannot force conscience uniformity, and you can’t have peace or rigor without educational freedom. Tennessee is just helping to make that clear.