RALEIGH — Advocates of greater parental choice in education advance a variety of arguments for their cause. Competition would improve the quality of schooling. A broader array of choices would lead to a better “fit” between child and academic environment. Markets would squeeze inefficiencies out of the government monopoly schools. And so on.

I’ve always thought, however, that perhaps the most persuasive argument for school choice has little to do with academic performance or cost-effectiveness — though I believe both to be important, and likely to improve as educational freedom expands.

What I’m talking about is the “diversity of values” argument. That is, a major source of bitter controversy within public-school systems is the inability of individual schools to define and reinforce a shared value system among their teachers, parents, and children. Some people prefer a “progressive,” open-classroom model. Some prefer a more traditional approach. There are major differences among families in religious outlook, in moral values, in styles of discipline, and in social standards and behaviors.

In an all-or-nothing world, many of these conflicts cannot be resolved without someone winning — and someone else losing. You either start each school day in a system with a (voluntary but customary) prayer or, fearful of offending someone, you don’t. You either teach abstinence-based sex education in the district or you don’t. You either impose a “zero-tolerance” policy in areas such as weapons and drugs, or you use a more common-sense approach that distinguishes between handguns and dinner knives, or between meth and Motrin.

In an educational marketplace based on voluntary associations, however, many of these win-lose choices can become win-win choices. Like-minded parents can choose schools that best reflect their values. Ideally, this system should allow for a continuum of government involvement — ranging from today’s district-run public schools, entirely subject to the regulatory authority of government officials and funded by tax dollars, to private and religious schools where students are eligible for scholarships or tax breaks to help defray the cost of tuition. In such an environment, parental values need never be sacrificed at the altar of political correctness or social convention.

I was reminded of how important this is when I ran across a story out of Australia where several day-care centers have banned the wearing of superhero costumes, citing an alleged link between Batman or Spider-Man role-playing and violent behavior. Naturally, this outrage caught my attention for the obvious reason. But what also stood out to me was how refreshing it was that this debate was occurring within day-care centers instead of within public-school systems. In the former, attendance is voluntary and diverse alternatives exist. Parents have no power to demand that everyone else comply with their preferences about clothing, toys, corporal punishment, or anything else.

Shortly after reading the piece, I left work for the day and headed to my oldest son’s school to pick him up. A couple of years ago, my wife and I decided for a number of reasons to make some sacrifices and start his educational career in a private school. One of those reasons became obvious this afternoon, as I approached Alex and his friends playing on the multipurpose-room floor. “What are you playing with?” I asked him.

“Army men,” he replied, “the green ones are the good guys and the yellow ones are the bad guys.”

No trendy “ban the violent toys” nonsense here. And no moral relativism.

“And whose army guys are those?” I asked.

“My teacher’s,” he said.

Excellent.

Hood is president of the John Locke Foundation and publisher of Carolina Journal.