The Texas State Board of Education this month approved new curriculum standards for US history and social studies. The standards — which dictate what will be taught in Texas public schools and incorporated in textbooks and achievement tests — include teaching students about the “unintended consequences” of the Great Society, the link between McCarthyism and “Soviet agent infiltration of the US government,” and how government regulations and taxes affect consumer prices. Critics (mostly liberal) blasted the new standards as a politicized travesty; supporters (mostly conservative) praised them as a long-overdue rebalancing. After months of debate, they were adopted on a party-line vote.

A new Arizona law, meanwhile, restricts what can be taught in ethnic studies classes in the state’s public schools. The measure bars any courses that “are designed primarily for pupils of a particular ethnic group” or “advocate ethnic solidarity instead of the treatment of pupils as individuals.” The legislation was a pet project of state school chief Tom Horne, a vocal opponent of the Mexican-American Studies Program in the Tucson public schools. The new law was greeted with indignation from Hispanic activists and a protest.

Such skirmishing over textbooks and classroom instruction is anything but new.

It was 85 years ago that John Scopes was indicted in Dayton, Tenn., for teaching Darwin’s theory of evolution. Scopes, a high school science teacher, was charged with violating a law passed by the Tennessee legislature and signed by the governor just two months earlier. His “monkey trial” that summer drew thousands of spectators and made front-page headlines nationwide. More than 80 years before that, a controversy over Bible reading in the Philadelphia public schools led to deadly riots, in which 25 residents were killed and dozens of homes and churches were burned down.

“Throughout American history,” writes Neal McCluskey of the Cato Institute, “public schooling has produced political disputes, animosity, and sometimes even bloodshed between diverse people.” Political fighting is neither rare nor anomalous: In the course of just one school year, 2005-06, McCluskey tallied almost 150 reported cases of public-school conflicts.

There were bitter battles that year over Darwinism-vs.-intelligent-design in Pennsylvania and Kansas, heated fights over books about Cuba in Florida, and an emotional dispute in California over the portrayal of Hindus in history texts. In Lexington, Mass., a teacher’s decision to read a story celebrating gay marriage to her second-grade class without first notifying parents triggered a fight that ultimately wound up in federal court.

Again and again, Americans find themselves at war with each other over public schooling. Yet furious conflict over religion in this country is almost unheard-of. Why? Why don’t American Catholics and Protestants angrily attack each other’s views of clerical celibacy or papal infallibility? Why is there no bitter struggle between Orthodox and Reform Jews to control the content of the Sabbath liturgy? Why don’t American atheists clash with American believers over whether children should be taught to pray before going to sleep?

Americans presumably feel as strongly about religion as they do about education. So why does the endless variety of religious life in the United States lead to so little strife, while the strife over public schooling never seems to end?

The answer is no mystery. America is a land of religious freedom, in which people decide for themselves what to believe and how to worship. No religion is funded by government. Elected officials have no say in the doctrine of any faith or the content of any religious service. Religion flourishes in America because church and state are separate. And it flourishes so peacefully because no one is forced to support anyone else’s faith, or to attend a church he isn’t happy with, or to bring up children according to the religious views of whichever faction has the most votes.

Religion is peaceful because it is government-free. Liberate the schools, and they too would be at peace. Taxpayer-funded, one-curriculum-fits-all schooling makes conflict inevitable. There would be far less animosity if parents were as free to choose how and where their children learn as they are to choose how and where they worship. Separation of church and state has made America an exemplar of religious pluralism and tolerance. Imagine what separation of school and state could do for education.

© Copyright 2010 Globe Newspaper Company.